Author: "Lionel Salmon" - Searchworks@Jio Institute Digital Library Search Results

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270 results on '"Lionel Salmon"'

1. Stereolithography 3D Printing of Stimuli-Responsive Spin Crossover@Polymer Nanocomposites with Optimized Actuating Properties

Author: Onkar Kulkarni, Alejandro Enriquez-Cabrera, Xinyu Yang, Julie Foncy, Liviu Nicu, Gábor Molnár, and Lionel Salmon
Subjects: stereolithography, nanocomposites, spin crossover, mechanical properties, Chemistry, QD1-999
Abstract: We used stereolithography to print polymer nanocomposite samples of stimuli-responsive spin crossover materials in the commercial photo-curable printing resins DS3000 and PEGDA-250. The thermomechanical analysis of the SLA-printed objects revealed not only the expected reinforcement of the polymer resins by the introduction of the stiffer SCO particles, but also a significant mechanical damping, as well as a sizeable linear strain around the spin transition temperatures. For the highest accessible loads (ca. 13–15 vol.%) we measured transformation strains in the range of 1.2–1.5%, giving rise to peaks in the coefficient of thermal expansion as high as 10−3 °C−1, which was exploited in 3D printed bilayer actuators to produce bending movement. The results pave the way for integrating these advanced stimuli-responsive composites into mechanical actuators and 4D printing applications.
Published: 2024
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2. Soft Actuators Based on Spin‐Crossover Particles Embedded in Thermoplastic Polyurethane

Author: Yue Zan, Mario Piedrahita-Bello, Seyed E. Alavi, Gábor Molnár, Bertrand Tondu, Lionel Salmon, and Azzedine Bousseksou
Subjects: actuator identification and control, bilayer beams, polymer composites, soft actuators, spin crossovers, Computer engineering. Computer hardware, TK7885-7895, Control engineering systems. Automatic machinery (General), TJ212-225
Abstract: Molecular spin‐crossover (SCO) complexes are phase‐change materials that develop large spontaneous strains across the thermally induced phase transition, which can be advantageously used in designing soft actuators. Herein, a bilayer bending cantilever, made of thermoplastic polyurethane (TPU) with embedded [Fe(NH2trz)3](SO4) SCO particles (25 wt%), is presented. The proposed actuator is fabricated by blade casting an SCO@TPU layer on a conducting Ag@TPU film to convert electrothermal input into mechanical response. Experiments are conducted to characterize the curvature of bilayer beams, which is then further analyzed using the Euler–Bernoulli beam theory. The beam curvature change, free transformation strain, and effective work density associated with the SCO are 0.11 mm−1, 1.6%, and 1.25 mJ cm−3, respectively. Further, the open‐ and closed‐loop response of the actuator is investigated using a custom‐built setup. The open‐loop identification suggests that the actuator gain increases monotonously when the control current increases. This natural adaptive character can explain the drastically diminished response time in closed‐loop proportional–integral–derivative control experiments (2–3 s). Finally, tracking experiments are carried out to evaluate the robustness of the actuator with and without payloads. The results for 30 240 endurance cycles reveal a mean positioning error of 0.8%.
Published: 2023
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3. Unprecedented switching endurance affords for high-resolution surface temperature mapping using a spin-crossover film

Author: Karl Ridier, Alin-Ciprian Bas, Yuteng Zhang, Lucie Routaboul, Lionel Salmon, Gábor Molnár, Christian Bergaud, and Azzedine Bousseksou
Subjects: Science
Abstract: Developing novel thermometry techniques for nanoscale temperature measurements are vital for realizing efficient thermal management of nanoscale devices. Here, the authors report thermally stable spin-crossover material-based nanothermometers for high-resolution surface temperature mapping.
Published: 2020
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4. Morphological Studies of Composite Spin Crossover@SiO2 Nanoparticles

Author: Yue Zan, Lionel Salmon, and Azzedine Bousseksou
Subjects: reverse microemulsion, nanoparticles, core@shell, spin crossover, Chemistry, QD1-999
Abstract: Spin crossover (SCO) iron (II) 1,2,4-triazole-based coordination compounds in the form of composite SCO@SiO2 nanoparticles were prepared using a reverse microemulsion technique. The thickness of the silica shell and the morphology of the as obtained core@shell nanoparticles were studied by modifying the polar phase/surfactant ratio (ω), as well as the quantity and the insertion phase (organic, aqueous and micellar phases) of the tetraethylorthosilicate (TEOS) precursor, the quantity of ammonia and the reaction temperature. The morphology of the nanoparticles was monitored by transmission electron microscopy (TEM/HRTEM) while their composition probed by combined elemental analyses, thermogravimetry and EDX analyses. We report that not only the particle size can be controlled but also the size of the silica shell, allowing for interesting perspectives in post-synthetic modification of the shell. The evolution of the spin crossover properties associated with the change in morphology was investigated by variable temperature optical and magnetic measurements.
Published: 2021
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5. Investigation of the Effect of Spin Crossover on the Static and Dynamic Properties of MEMS Microcantilevers Coated with Nanocomposite Films of [Fe(Htrz)2(trz)](BF4)@P(VDF-TrFE)

Author: José Elías Angulo-Cervera, Mario Piedrahita-Bello, Fabrice Mathieu, Thierry Leichle, Liviu Nicu, Lionel Salmon, Gábor Molnár, and Azzedine Bousseksou
Subjects: spin crossover, MEMS, mechanical properties, Chemistry, QD1-999
Abstract: We used a spray-coating process to cover silicon microcantilevers with ca. 33 wt% [Fe(Htrz)2(trz)](BF4)@P(VDF70-TrFE30) nanocomposite thin films of 1500 nm thickness. The bilayer cantilevers were then used to investigate the thermomechanical properties of the composites through a combined static and dynamic flexural analysis. The out-of-plane flexural resonance frequencies were used to assess the Young’s modulus of the spray-coated films (3.2 GPa). Then, the quasi-static flexural bending data allowed us to extract the actuation strain (1.3%) and an actuation stress (7.7 MPa) associated with the spin transition in the composite.
Published: 2021
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6. Water Soluble Iron-Based Coordination Trimers as Synergistic Adjuvants for Pancreatic Cancer

Author: Marco Cordani, Esther Resines-Urien, Arturo Gamonal, Paula Milán-Rois, Lionel Salmon, Azzedine Bousseksou, Jose Sanchez Costa, and Álvaro Somoza
Subjects: pancreatic cancer, antitumor agents, coordination polymers, bioinorganic chemistry, reactive oxygen species, Therapeutics. Pharmacology, RM1-950
Abstract: Pancreatic cancer is a usually fatal disease that needs innovative therapeutic approaches since the current treatments are poorly effective. In this study, based on cell lines, triazole-based coordination trimers made with soluble Fe(II) in an aqueous media were explored for the first time as adjuvant agents for the treatment of this condition. These coordination complexes were effective at relatively high concentrations and led to an increase in reactive oxygen species (ROS) in two pancreatic cancer cell lines, PANC-1 and BXPC-3, and this effect was accompanied by a significant reduction in cell viability in the presence of gemcitabine (GEM). Importantly, the tested compounds enhanced the effect of GEM, an approved drug for pancreatic cancer, through apoptosis induction and downregulation of the mTOR pathway. Although further evaluation in animal-based models of pancreatic cancer is needed, these results open novel avenues for exploring these iron-based materials in biomedicine in general and in pancreatic cancer treatment.
Published: 2021
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7. Hybrid spin-crossover nanostructures

Author: Carlos M. Quintero, Gautier Félix, Iurii Suleimanov, José Sánchez Costa, Gábor Molnár, Lionel Salmon, William Nicolazzi, and Azzedine Bousseksou
Subjects: core–shell particle, multifunctionality, nanomaterials, spin-crossover, Technology, Chemical technology, TP1-1185, Science, Physics, QC1-999
Abstract: This review reports on the recent progress in the synthesis, modelling and application of hybrid spin-crossover materials, including core–shell nanoparticles and multilayer thin films or nanopatterns. These systems combine, often in synergy, different physical properties (optical, magnetic, mechanical and electrical) of their constituents with the switching properties of spin-crossover complexes, providing access to materials with unprecedented capabilities.
Published: 2014
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8. Bilayer Thin Films That Combine Luminescent and Spin Crossover Properties for an Efficient and Reversible Fluorescence Switching

Author: Alin-Ciprian Bas, Xavier Thompson, Lionel Salmon, Christophe Thibault, Gábor Molnár, Oleg Palamarciuc, Lucie Routaboul, and Azzedine Bousseksou
Subjects: spin crossover, luminescence, thin films, Chemistry, QD1-999
Abstract: We report on the vacuum thermal deposition of bilayer thin films of the luminescent complex Ir(ppy)3, tris[2-phenylpyridinato-C2,N]iridium(III), and the spin crossover complex [Fe(HB(tz)3)2], bis[hydrotris(1,2,4-triazol-1-yl)borate]iron(II). Switching the spin state of iron ions from the low spin to the high spin state around 337 K leads to a reversible jump of the luminescence intensity, while the spectrum shape and the luminescence lifetime remain unchanged. The luminescence modulation occurs due to the different UV light absorption properties of the iron complex in the two spin states and its magnitude can therefore be precisely adjusted by varying the film thickness. These multilayer luminescence switches hold potential for micro- and nanoscale thermal sensing and imaging applications.
Published: 2019
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9. In Situ AFM Imaging of Microstructural Changes Associated with The Spin Transition in [Fe(Htrz)2(Trz)](Bf4) Nanoparticles

Author: María D. Manrique-Juárez, Iurii Suleimanov, Edna M. Hernández, Lionel Salmon, Gábor Molnár, and Azzedine Bousseksou
Subjects: spin crossover, microstructures, atomic force microscopy, Technology, Electrical engineering. Electronics. Nuclear engineering, TK1-9971, Engineering (General). Civil engineering (General), TA1-2040, Microscopy, QH201-278.5, Descriptive and experimental mechanics, QC120-168.85
Abstract: Topographic images of [Fe(Htrz)2(trz)](BF4) nanoparticles were acquired across the first-order spin transition using variable-temperature atomic force microscopy (AFM) in amplitude modulation mode. These studies revealed a complex morphology of the particles consisting of aggregates of small nanocrystals, which expand, separate and re-aggregate due to the mechanical stress during the spin-state switching events. Both reversible (prompt or slow recovery) and irreversible effects (fatigue) on the particle morphology were evidenced and correlated with the spin crossover properties.
Published: 2016
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10. Dramatic acceleration by visible light and mechanism of AuPd@ZIF-8-catalyzed ammonia borane methanolysis for efficient hydrogen production

Author: Naixin Kang, Ruofan Shen, Baojun Li, Fangyu Fu, Bruno Espuche, Sergio Moya, Lionel Salmon, Jean-Luc Pozzo, and Didier Astruc
Subjects: Renewable Energy, Sustainability and the Environment, General Materials Science, General Chemistry
Abstract: The novel nanomaterials AuxPdy@ZIF-8 catalyze H2-producing ammonia borane methanolysis; the reaction is considerably boosted by visible-light irradiation and ZIF-8 surpassing other supports. KIE studies and DFT calculations delineate the mechanism.
Published: 2023

11. High-Sensitivity Microthermometry Method Based on Vacuum-Deposited Thin Films Exhibiting Gradual Spin Crossover above Room Temperature

Author: Oleksandr Ye. Horniichuk, Karl Ridier, Lijun Zhang, Yuteng Zhang, Gábor Molnár, Lionel Salmon, Azzedine Bousseksou, Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Department of Chemistry, Taras Shevchenko National University of Kyiv, and Taras Shevchenko National University of Kyiv
Subjects: Thermoreflectance imaging, Microthermometry, Vacuum thermal evaporation, Thin films, [CHIM.COOR]Chemical Sciences/Coordination chemistry, General Materials Science, Spin crossover
Abstract: International audience; We report on the fabrication, characterization, and microthermometry application of high-quality, nanometric thin films, with thicknesses in the range 20–200 nm, of the molecular spin-crossover complex [Fe(HB(1,2,3-triazol-1-yl)3)2]. The films were obtained by vacuum thermal evaporation and characterized by X-ray diffraction, UV spectrophotometry, and atomic force microscopy. The as-deposited films are dense and crystalline with a preferred [011] orientation of the monoclinic crystal lattice normal to the substrate surface. The films exhibit a gradual spin conversion centered at ca. 374 K spanning the 273–473 K temperature range, irrespective of their thickness. When deposited on a microelectronic device, these films can be used to enhance the UV-light thermoreflectance coefficient of reflective surfaces by more than an order of magnitude, allowing for high-sensitivity thermoreflectance thermal imaging.
Published: 2022

12. Solvatomorphism, polymorphism and spin crossover in bis[hydrotris(1,2,3-triazol-1-yl)borate]iron(<scp>ii</scp>)

Author: Oleksandr Ye. Horniichuk, Karl Ridier, Gábor Molnár, Volodymyr O. Kotsyubynsky, Sergiu Shova, Vladimir M. Amirkhanov, Il’ya A. Gural'skiy, Lionel Salmon, Azzedine Bousseksou, Department of Chemistry, Taras Shevchenko National University of Kyiv, Taras Shevchenko National University of Kyiv, Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Vasyl Stefanyk Precarpathian National University, 'Petru Poni' Institute of Macromolecular Chemistry, and Ministry of Education and Science of Ukraine (grant 22BF037-09)
Subjects: Materials Chemistry, [CHIM.COOR]Chemical Sciences/Coordination chemistry, General Chemistry, Catalysis
Abstract: International audience; Solvatomorphism and polymorphism play a crutial role in defining charachteristics of spin crossover (SCO) in coordination compounds. In this paper we describe a detailed characterization of the SCO bis[hydrotris(1,2,3-triazol-1-yl)borate]iron(II) complex ([Fe(HB(1,2,3-tz)3)2]) 1. Five solvatomorphs of 1∙2Solv (where Solv = DMSO, MeOH, CHCl3), 1∙7DMSO and 1∙2DMF∙H2O were obtained ¬via recrystallization from the respective organic solvents. Solvatomorphs 1∙2MeOH and 1∙2CHCl3 undergo single-crystal-to-single-crystal transformations leading to 1 upon heating above 313 K. Single-crystal X-Ray diffraction analysis revealed π-π stacking and C–H···N contacts between molecules of the complex both in the solvated and desolvated crystals. Spin crossover and thermal properties of 1 and its solvates were investigated by means of calorimetry, thermogravimetry, Mössbauer spectroscopy, variable temperature magnetic susceptibility, Raman spectroscopy and powder X-Ray diffraction measurements. The anhydrous [Fe(HB(1,2,3-tz)3)2] complex, obtained via dehydration of the dodecahydrate, undergoes structural phase transitions upon the first heating in the 303-493 K range followed by reversible, gradual spin crossover upon further thermal cycling, with a transition temperature of T1/2 = 373 K.
Published: 2022

13. Switching endurance of the molecular spin crossover complex [Fe(HB(tz)3)2]: from single crystals to thin films and electronic devices

Author: Yuteng Zhang, Lijun Zhang, Karl Ridier, Lionel Salmon, Isabelle Séguy, Gábor Molnár, and Azzedine Bousseksou
Subjects: Chemistry (miscellaneous), General Materials Science
Abstract: The spin-state switching behavior of [Fe(HB(tz)3)2] remains virtually unaltered for more than 104 endurance cycles in ambient air in single crystals, thin films and metal–insulator–metal junctions, highlighting the scope for technological applications.
Published: 2022

14. Facile MOF Support Improvement in Synergy with Light Acceleration for Efficient Nanoalloy-Catalyzed H2 Production from Formic Acid

Author: Yue Liu, Fangyu Fu, Lionel Salmon, Bruno Espuche, Sergio Moya, Murielle Berlande, Jean-Luc Pozzo, Jean-René Hamon, Didier Astruc, Institut des Sciences Moléculaires (ISM), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1 (UB)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Beijing Institute of Technology (BIT), Laboratoire de cryptographie et composants (LCC), Agence nationale de la sécurité des systèmes d'information (ANSSI), Centro de Investigación Cooperativa en Biomateriales (CIC biomaGUNE), University of the Basque Country/Euskal Herriko Unibertsitatea (UPV/EHU), China Scholarship Council (CSC), Ministerio de Economia, Industria y Competitividad, gobierno de Espana [MAT2017-88752-R], Centre National de la Recherche Scientifique (CNRS), University of Bordeaux, and University of Rennes
Subjects: plasmonic acceleration, hydrogen production, [CHIM]Chemical Sciences, General Materials Science, formic acid dehydrogenation, [CHIM.MATE]Chemical Sciences/Material chemistry, PdAg nanoalloy, double ZIF
Abstract: International audience; Hydrogen (H2) generation and storage are actively investigated to provide a green source of energy, and formic acid (HCOOH), a major product obtained from the biomass, is regarded as a productive source of H2. Therefore, improvements in heterogeneous catalysts are called for. Here, a novel type of catalyst support is proposed involving simple addition of the mixture of metal ion precursors to core-shell ZIF-8@ZIF-67, followed by reduction with NaBH4, with performances surpassing those obtained using nanocatalysts in ZIF-8 or ZIF-67. The nanocatalysts PdxAg were optimized with ZIF-8@Pd2Ag1@ZIF-67 under visible-light illumination for selective HCOOH dehydrogenation involving a turnover frequency value of 430 h-1 under light irradiation at 353 K. These results also reveal the crucial roles of the Pd sites electronically promoted in the presence of visible by the plasmon resonance and the core-shell light by Ag plasmon advantageous MOF structure. In order to examine the potential of extending this catalyst improvement principle to other catalytic reactions, 4nitrophenol reduction, a benchmarking model of catalytic reaction, was tested, and the results also confirmed the superiority of the performance of ZIF-8@Pd2Ag1@ZIF-67 over Pd2Ag1@ZIF-8 and Pd2Ag1@ZIF-67, confirming the interest in the novel catalyst design.
Published: 2023

15. Design and synthesis of benzothiadiazole-based molecular systems: self-assembly, optical and electronic properties

Author: Montserrat Miranda-Olvera, Rafael Arcos-Ramos, Mauricio Maldonado-Domínguez, Lionel Salmon, Gábor Molnár, Azzedine Bousseksou, María del Pilar Carreón-Castro, Instituto de Ciencias Nucleares, UNAM, Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM), Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), J. Heyrovský Institute of Physical Chemistry of the ASCR, Czech Academy of Sciences [Prague] (CAS), DGAPA-UNAM (PAPIIT IN-207421), SEP-CONACYT-ANUIES-ECOS Francia (296682) Ingeniería de películas delgadas basadas en compuestos de transición de espín para aplicaciones en micro(opto)electromecánicos, and Ministry of Education, Youth and Sports of the Czech Republic - e-INFRA CZ (ID:90140)
Subjects: Materials Chemistry, [CHIM.COOR]Chemical Sciences/Coordination chemistry, General Chemistry, Catalysis
Abstract: International audience; A set of small benzothiadiazole (BTD)-based derivatives with a D–A–D architecture were synthesized and characterized as building blocks of organic semiconducting materials by applying an experimental–theoretical approach. The four derivatives tend to self-assemble into highly ordered crystalline solids, with varying degrees of responsiveness to mechanical and thermal stimuli. The featured derivatives exhibit absorption maxima in solution and molar extinction coefficient values related to π–π* electronic transitions with minor solvatochromic responses, displaying broad fluorescence profiles with large Stokes shifts and high fluorescence quantum yields. In the solid-state, the BTD derivatives display absorption maxima in the visible range and intense fluorescence emission of the n-butoxy and fluorene derivatives. The stability of the one-electron reduced and oxidized forms of all compounds was assessed by means of cyclic voltammetry, which complemented by DFT calculations allowed the identification of one BTD derivative (BuO-BTD) as a strong candidate for use as an electron transport layer in organoelectronic devices.
Published: 2022

16. Sharp Volcano-Type Synergy and Visible Light Acceleration in H 2 Release upon B 2 (OH) 4 Hydrolysis Catalyzed by Au-Rh@Click-Dendrimer Nanozymes

Author: Qiuxia Zhao, Naixin Kang, Marta Martinez Moro, Eduardo Guisasola Cal, Sergio Moya, Emerson Coy, Lionel Salmon, Xiang Liu, Didier Astruc, Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Moléculaires (ISM), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1 (UB)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centro de Investigación Cooperativa en Biomateriales (CIC biomaGUNE), Adam Mickiewicz University in Poznań (UAM), China Three Gorges University, China Scholarship Council, National Science Centre of Poland - the program OPUS, National Natural Science Foundation of China, CNRS, and University of Bordeaux
Subjects: B2(OH)4 hydrolysis, Nanozyme, Energy Engineering and Power Technology, Volcano synergy effect, [CHIM.CATA]Chemical Sciences/Catalysis, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, Materials Chemistry, Electrochemistry, Hydrogen production, Chemical Engineering (miscellaneous), Rhodium, Plasmonic rate enhancement, Gold, Electrical and Electronic Engineering, Visible light acceleration
Abstract: International audience; Hydrogen (H2) formation from hydrogen-rich precursors is a hot topic, whereby carbon-free energy perspectives, mechanistic features, and synthetic applications are actively searched. Here, we report oxygen atom uptake from water under ambient conditions, producing H2 in the presence of alloyed Au-Rh nanoparticle catalysts encapsulated in a “click”-dendrimer. These systems are named nanozymes (NZs) because their function and mechanism resemble those of hydrogenase enzymes. The Au-Rh NZs with variable proportions of Au and Rh exhibit positive sharp volcano-type synergy and visible light-induced acceleration. The best synergy in the dark is disclosed in Au4Rh1, achieving a turnover frequency (TOFs) of 5100 molH2 molcata–1 min–1 in dark, 3.4 times higher than the related Au NZ and 8.9 times higher than the related Rh NZ at 25 ± 1 °C. The catalytic activity of Au-Rh for H2 evolution is enhanced by visible light irradiation due to the Au plasmon, so that the synergistic effect in the dark and the visible light-induced rate enhancement cumulate for Au4Rh1, allowing for complete B2(OH)4 hydrolysis in 39 s at 25 ± 1 °C (TOFs = 6000 molH2 molcata–1 min–1). Upon increasing the Rh content, Au-Rh provides less synergy in the dark, whereas the light enhancement of the reaction rate increases, reaching a maximum for Au1Rh2. Experiments using D2O, including kinetic isotope effect determination, suggest that the rate-determining step of the reaction involves concerted O–H bond cleavage of water and support the proposed catalytic reaction mechanism.
Published: 2022

17. Post-synthetic modification mechanism for 1D spin crossover coordination polymers

Author: Alejandro Enríquez-Cabrera, Livia Getzner, Lionel Salmon, Lucie Routaboul, Azzedine Bousseksou, Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), and ANR-19-CE09-0008,NAGAM,Actionnement nanomoléculaire pour une nouvelle génération de muscles artificiels(2019)
Subjects: [CHIM.POLY]Chemical Sciences/Polymers, Materials Chemistry, [CHIM.COOR]Chemical Sciences/Coordination chemistry, General Chemistry, Catalysis
Abstract: International audience; In this work we present a comprehensive study of the influence of the solvent on the post-synthetic modification (PSM) on the [Fe(NH2trz)3](NO3) spin crossover (SCO) complex with p-anisaldehyde. We demonstrate that the use of a suitable solvent such as ethanol results in a complete PSM, where the final crystalline material exhibits a gradual conversion just below room temperature. In the other hand, when an unsuitable solvent such as toluene or 1-octanol is used, either no reaction or very long reaction time is needed, leading to undesired Fe(III) species. Transmission electronic microscopy analyses show that the complete PSM reaction carried out on nanoparticles of the same complex, changes drastically the size and morphology of the particles.
Published: 2022

18. Thermal hysteresis of stress and strain in spin-crossover@polymer composites: towards a rational design of actuator devices

Author: José Elias Angulo-Cervera, Mario Piedrahita-Bello, Baptiste Martin, Seyed Ehsan Alavi, William Nicolazzi, Lionel Salmon, Gábor Molnár, Azzedine Bousseksou, Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), and European Project: 101019522,https://cordis.europa.eu/project/id/101019522/fr,E-MOTION(2021)
Subjects: [PHYS.MECA.MEMA]Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph], [CHIM.POLY]Chemical Sciences/Polymers, Chemistry (miscellaneous), General Materials Science, [CHIM.COOR]Chemical Sciences/Coordination chemistry
Abstract: International audience; Polymer composites of molecular spin crossover complexes have emerged as promising mechanical actuator materials, but their effective thermomechanical properties remain elusive. In this work, we investigated a series of iron(II)-triazole@P(VDF-TrFE) particulate composites using a tensile testing stage with temperature control. From these measurements, we assessed the temperature dependence of the Young's modulus as well as the free deformation and blocking stress, associated with the thermally-induced spin transition. The results denote that the expansion of the particles at the spin transition is effectively transferred to the macroscopic composite material, providing ca. 1–3% axial strain for 25% particle load. This strain is in excess of the ‘neat’ particle strain, which we attribute to particle-matrix mechanical coupling. On the other hand, the blocking stress (∼1 MPa) appears reduced by the softening of the composite around the spin transition temperature.
Published: 2022

19. Fast Au-Ni@ZIF-8-catalyzed ammonia borane hydrolysis boosted by dramatic volcano-type synergy and plasmonic acceleration

Author: Naixin Kang, Xiaorong Wei, Ruofan Shen, Baojun Li, Eduardo Guisasola Cal, Sergio Moya, Lionel Salmon, Changlong Wang, Emerson Coy, Murielle Berlande, Jean-Luc Pozzo, and Didier Astruc
Subjects: Process Chemistry and Technology, Catalysis, General Environmental Science
Published: 2023

20. Investigation of the Effect of Spin Crossover on the Static and Dynamic Properties of MEMS Microcantilevers Coated with Nanocomposite Films of [Fe(Htrz)2(trz)](BF4)@P(VDF-TrFE)

Author: Lionel Salmon, Fabrice Mathieu, Gábor Molnár, Azzedine Bousseksou, Thierry Leichle, José Elias Angulo-Cervera, Mario Piedrahita-Bello, Liviu Nicu, Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Équipe Microsystèmes électromécaniques (LAAS-MEMS), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Équipe Mouvement des Systèmes Anthropomorphes (LAAS-GEPETTO), Service Instrumentation Conception Caractérisation (LAAS-I2C), Georgia Tech Lorraine [Metz], Ecole Nationale Supérieure des Arts et Metiers Metz-Georgia Institute of Technology [Atlanta]-Ecole Supérieure d'Electricité - SUPELEC (FRANCE)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), CONACyT-Mexico, Occitanie Region/Federal University of Toulouse, ANR-19-CE09-0008,NAGAM,Actionnement nanomoléculaire pour une nouvelle génération de muscles artificiels(2019), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Université de Franche-Comté (UFC), and Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Ecole Supérieure d'Electricité - SUPELEC (FRANCE)-Georgia Institute of Technology [Atlanta]-CentraleSupélec-Ecole Nationale Supérieure des Arts et Metiers Metz-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, spin crossover, MEMS, mechanical properties, Composite number, Spin transition, Mechanical properties, 02 engineering and technology, Bending, 010402 general chemistry, 01 natural sciences, Stress (mechanics), Flexural strength, Spin crossover, Materials Chemistry, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Composite material, QD1-999, Nanocomposite, Bilayer, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, Chemistry, Chemistry (miscellaneous), 0210 nano-technology
Abstract: We used a spray-coating process to cover silicon microcantilevers with ca. 33 wt% [Fe(Htrz)2(trz)](BF4)@P(VDF70-TrFE30) nanocomposite thin films of 1500 nm thickness. The bilayer cantilevers were then used to investigate the thermomechanical properties of the composites through a combined static and dynamic flexural analysis. The out-of-plane flexural resonance frequencies were used to assess the Young’s modulus of the spray-coated films (3.2 GPa). Then, the quasi-static flexural bending data allowed us to extract the actuation strain (1.3%) and an actuation stress (7.7 MPa) associated with the spin transition in the composite.
Published: 2021

21. Smart Sensing of Vital-Signs: Co-Design of Tunable Quantum-Spin Crossover Materials with Secure Photonics and RF Front-End-Module

Author: Azzedine Bousseksou, S. Wane, Q.H. Tran, A. E. Cabrera, V. Huard, Lionel Salmon, and Gábor Molnár
Subjects: RF front end, Application-specific integrated circuit, business.industry, Computer science, Crossover, Hardware_INTEGRATEDCIRCUITS, Electrical engineering, Silicon on insulator, System on a chip, Radio frequency, Photonics, business, Wireless sensor network
Abstract: In this paper, a new sensor technology solution is proposed based on the co-design of tunable quantum-spin crossover material with smart photonics and RF Front-End-Module (FEM) integrating innovative Thermal-Body harvesting. The quantum-spin crossover material, co-integrated with the Photonics and RF Front-End-Module, hosts smart Low-Power Signal-Processor (LPSP) embedding Artificial-Intelligence (AI) and Machine-Learning (ML) algorithms for accurate sensing of vital-signs information. The smart signal-processing capabilities are brought near the sensor to allow for real-time Correlation-based data analytics and decision-making process with secure wireless data transfer. The performances of the proposed technology solution are demonstrated by building a smart wearable Bracelet device for real-time sensing of Correlated body temperature and oxygen saturation levels. Porting of the Photonics and RF FEM into 22nm Fully Depleted Silicon On Insulator (FD-SOI) platform using Application Specific Integrated Circuit-based System on a Chip (ASIC-SoC) technology solution will foster a broad range of applications in mobile communications with smart devices and systems.
Published: 2021

22. Dramatic Synergy in CoPt Nanocatalysts Stabilized by 'Click' Dendrimers for Evolution of Hydrogen from Hydrolysis of Ammonia Borane

Author: Marta Martinez Moro, Fangyu Fu, Lionel Salmon, Maria de los Angeles Ramirez, Didier Astruc, Sha Yang, Qi Wang, Sergio Moya, Jaime Ruiz, Institut des Sciences Moléculaires (ISM), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1 (UB)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Anhui University [Hefei], Unidad Biosuperficies (CIC biomaGUNE), Centro de Investigación Cooperativa en Biomateriales (CIC biomaGUNE), Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), China Scholarship Council (CSC) of the People’s Republic of China, Centre National de la Recherche Scientifique (CNRS), University of Bordeaux, CIC biomaGUNE at San Sebastian, Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: AMMONIA BORANE, Reaction mechanism, NANOCATALYST, DENDRIMER, Ammonia borane, 010402 general chemistry, 01 natural sciences, 7. Clean energy, Catalysis, Reaction rate, chemistry.chemical_compound, Cascade reaction, purl.org/becyt/ford/2.10 [https], Dendrimer, COBALT, [CHIM.COOR]Chemical Sciences/Coordination chemistry, SYNERGY, Bond cleavage, 010405 organic chemistry, Chemistry, General Chemistry, HYDROLYSIS, Combinatorial chemistry, Nanomaterial-based catalyst, 0104 chemical sciences, purl.org/becyt/ford/2 [https]
Abstract: Hydrolysis of ammonia borane (AB) is a very convenient source of H 2 , but this reaction needs catalytic activation to become practical under ambient conditions. Here this reaction is catalyzed by bimetallic late transition-metal nanoparticles (NPs) that are stabilized and activated by "click" dendrimers. Dendrimers 1 and 2 contain 27 or 81 triethylene glycol terminal groups and 9 or 27 1,2,3-triazole ligands, respectively, located on the dendritic tethers. A remarkable synergy between Pt and Co in the Pt-Co/"click" dendrimer nanocatalysts is revealed. These Pt-Co/"click" dendrimer catalysts are much more efficient for hydrolysis of AB than either "click" dendrimer-stabilized Co or Pt analogues alone. The best catalyst, Pt 1 Co 1 1, stabilized by the nonatriazole "click" dendrimer 1 achieves a turnover frequency number (TOF) of 303 mol H 2 mol cat -1 min -1 (606 mol H 2 mol Pt -1 min -1 ) at 20 ± 1 °C. The AB hydrolysis reaction catalyzed by Pt 1 Co 1 1 is boosted by NaOH, the TOF value reaching 476.2 mol H 2 mol cat -1 min -1 (952.4 mol H2 mol Pt -1 min -1 ), one of the very best results ever obtained for this reaction. The presence of ≥25% Pt in the CoPt nanoalloy provides a reaction rate higher than that obtained with the pure PtNP catalyst alone. The kinetics involves in particular a kinetic isotope effect k D k H of 2.46 obtained for the hydrolysis reaction with D 2 O, suggesting that an O-H bond of water is cleaved in the rate-determining step. Tandem reactions were carried out for the hydrogenation of styrene with hydrogen generated from the hydrolysis of AB. Performing this tandem reaction with D 2 O shows deuteration of the ethylbenzene products, confirming O-D bond cleavage and H/D scrambling on the bimetallic NP surface. Finally, a full reaction mechanism is proposed. This dramatic synergy type should also prove to be useful in a number of other catalytic systems. Fil: Wang, Qi. Universite de Bordeaux; Francia. Centre National de la Recherche Scientifique; Francia Fil: Fu, Fangyu. Universite de Bordeaux; Francia. Centre National de la Recherche Scientifique; Francia Fil: Yang, Sha. Anhui University; China Fil: Martinez Moro, Marta. Centro de Investigacion Cooperativa En Biomateriales.; España Fil: Ramirez, Maria de Los Angeles. Centro de Investigacion Cooperativa En Biomateriales.; España. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Moya, Sergio Enrique. Centro de Investigacion Cooperativa En Biomateriales.; España Fil: Salmon, Lionel. Centre National de la Recherche Scientifique; Francia Fil: Ruiz, Jaime. Universite de Bordeaux; Francia. Centre National de la Recherche Scientifique; Francia Fil: Astruc, Didier. Universite de Bordeaux; Francia. Centre National de la Recherche Scientifique; Francia
Published: 2018

23. Spin Crossover Metal-Organic Frameworks with Inserted Photoactive Guests: On the Quest to Control the Spin State by Photoisomerization

Author: Francisco Javier Valverde-Muñoz, Ján Moncoľ, Azzedine Bousseksou, Ivan Šalitroš, Gábor Molnár, Lionel Salmon, Barbora Brachňaková, Sébastien Bonhommeau, Ján Pavlik, Lucie Routaboul, Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Slovak University of Technology in Bratislava, Faculty of Science [Univ Palacký], Palacky University Olomouc, Central European Institute of Technology [Brno] (CEITEC MU), Brno University of Technology [Brno] (BUT), Institut des Sciences Moléculaires (ISM), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Instituto de Ciencia Molecular (ICMol), Universitat de València (UV), Slovak grant agencies (APVV-18-0197, APVV-18-0016, APVV-19-0087, VEGA 1/0125/18, KEGA 018-STU-4), European Regional Development Fund : Operational Program Integrated Infrastructure for the project: 'Strategic research in the field of SMART monitoring, treatment and preventive protection against coronavirus (SARS-CoV-2)', project no. 313011ASS8, National Scholarship Programme of the Slovak Republic, Department of Inorganic Chemistry, Palacký University Olomouc, Czech Republic, Ministry of Education, Youth and Sports of the Czech Republic under the project CEITEC 2020 (LQ1601), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), and Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1 (UB)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Spin states, Photoisomerization, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Inorganic Chemistry, Thermogravimetry, Crystallography, chemistry.chemical_compound, symbols.namesake, Acetylene, chemistry, Spin crossover, symbols, [CHIM.CRIS]Chemical Sciences/Cristallography, Molecule, Metal-organic framework, [CHIM.COOR]Chemical Sciences/Coordination chemistry, 0210 nano-technology, Raman spectroscopy
Abstract: International audience; Three Hofmann-like metal-organic frameworks {Fe(bpac)[Pt(CN)4]}•G (bpac=1,2-bis(4-pyridyl)acetylene) were synthesized with photoisomerizable guest molecules (G = trans-azobenzene, trans-stilbene or cis-stilbene) and were characterized by elemental analysis, thermogravimetry and powder X-ray diffraction. The insertion of guest molecules and their conformation were inferred from Raman and FTIR spectra and from single-crystal X-ray diffraction and confronted with computational simulation. The magnetic and photomagnetic behaviors of the framework are significantly altered by the different guest molecules and different conformations. On the other hand, photoisomerization of the guest molecules becomes strongly hindered by the framework.
Published: 2021

24. Sequential Activation of Molecular and Macroscopic Spin-State Switching within the Hysteretic Region Following Pulsed Light Excitation

Author: Lionel Salmon, Gábor Molnár, Karl Ridier, Azzedine Bousseksou, William Nicolazzi, Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), European Project: 36241,SPINSWITCH, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), and SPINSWITCH project (H2020-MSCA-RISE-2016, Grant Agreement No.734322)
Subjects: Phase transition, Materials science, Bistability, Spin states, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Crystal, Pump-probe optical microscopy, Spin crossover, Metastability, General Materials Science, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Photo-responsive materials, Mechanical Engineering, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Dynamics, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Mechanics of Materials, Chemical physics, 0210 nano-technology, Single crystal, Excitation
Abstract: Molecular spin-crossover (SCO) compounds constitute a promising class of photoactive materials exhibiting efficient photo-induced phase transitions (PIPTs), driven by cooperative elastic interactions between the switchable molecules. Taking advantage of the unique, picture-perfect reproducibility of the spin-transition properties in the compound [Fe(HB(1,2,4-triazol-1-yl)3 )2 ], we have dissected the spatiotemporal dynamics of the PIPT within the thermodynamic metastability (hysteretic) region of a single crystal, using pump-probe optical microscopy. Beyond a threshold laser excitation density, complete PIPTs were evidenced, with conversion rates up to 200 switched molecules per absorbed photon. We show that the PIPT takes place through the sequential activation of two (molecular and macroscopic) switching mechanisms, occurring on sub-μs and ms timescales, governed by the intramolecular and free energy barriers of the system, respectively. The main finding here is that the thermodynamic metastability has strictly no influence on the sub-ms switching dynamics. Indeed, before this ms timescale, the response of the crystal to the laser excitation involves a gradual, molecular conversion process, as if there was no hysteresis loop. Consequently, in this regime, even a 100% photo-induced conversion may not give rise to a PIPT. These results provide new insight on the intrinsic dynamical limits of the PIPT in SCO solids (and other types of bistable materials), which is an important issue, from a technological perspective, for achieving fast and efficient photo-control of the functionalities of condensed matter. This article is protected by copyright. All rights reserved.
Published: 2021
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25. Complete and versatile post‐synthetic modification on iron‐triazole spin crossover complexes: a relevant material elaboration method

Author: Karl Ridier, Lucie Routaboul, Lionel Salmon, Alejandro Enríquez-Cabrera, Azzedine Bousseksou, Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), and ANR-19-CE09-0008,NAGAM,Actionnement nanomoléculaire pour une nouvelle génération de muscles artificiels(2019)
Subjects: Amide, Solid state reaction, 010405 organic chemistry, Imine, Triazole, 010402 general chemistry, 01 natural sciences, 0104 chemical sciences, Inorganic Chemistry, chemistry.chemical_compound, Crystallography, chemistry, Spin crossover, Post-Synthetic modification, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Spin Crossover
Abstract: International audience; In this paper we study the post‐synthetic modification (PSM) reaction on solid spin crossover (SCO) [Fe(NH 2 trz) 3 ]X 2 (X = NO 3 , OTs, Cl, SO 4 , BF 4 ) complexes with different substrates. The wide access to a diversity of functionalized complexes with imine, amide and carbamide groups from the same amino parent compound demonstrates the synthetic approach value of this method. The as‐obtained post‐synthetic complexes were studied by IR, solid NMR, elemental analyses and powder X‐ray diffraction, and compared to the corresponding compounds obtained by direct synthesis (DS) routes. Moreover, after digestion of the complexes obtained by PSM reactions, the free ligands were characterized by NMR in solution, which allowed us to indirectly confirm the formation of complexes we wished to synthesize. The study reveals in numerous cases that a complete post synthetic modification is possible despite the structural cohesion that is established between the 1D coordination chains within these materials. Spin crossover properties of some complexes obtained by both methods are also reported and compared.
Published: 2021

26. Photoactuation of micromechanical devices by photochromic molecules

Author: Barbora Brachňaková, Lucie Routaboul, Alejandro Enríquez-Cabrera, Liviu Nicu, Fabrice Mathieu, Mario Piedrahita-Bello, Lionel Salmon, José Elias Angulo-Cervera, Azzedine Bousseksou, Gábor Molnár, Thierry Leichle, Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Équipe Microsystèmes électromécaniques (LAAS-MEMS), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Slovak University of Technology in Bratislava, School of Electrical and Computer Engineering, Georgia Institute of Technology [Atlanta], Georgia Tech Lorraine [Metz], Ecole Nationale Supérieure des Arts et Metiers Metz-Georgia Institute of Technology [Atlanta]-Ecole Supérieure d'Electricité - SUPELEC (FRANCE)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Service Instrumentation Conception Caractérisation (LAAS-I2C), Occitanie Region, Federal University of Toulouse, CONACyT–Mexico, National Scholarship Programme of the Slovak Republic, LAAS-CNRS, ANR-19-CE09-0008,NAGAM,Actionnement nanomoléculaire pour une nouvelle génération de muscles artificiels(2019), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Université de Franche-Comté (UFC), and Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Ecole Supérieure d'Electricité - SUPELEC (FRANCE)-Georgia Institute of Technology [Atlanta]-CentraleSupélec-Ecole Nationale Supérieure des Arts et Metiers Metz-Centre National de la Recherche Scientifique (CNRS)
Subjects: Spiropyran, Nanocomposite, Materials science, Photoisomerization, Silicon, Resonance, chemistry.chemical_element, 02 engineering and technology, Bending, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Photochromism, chemistry.chemical_compound, chemistry, Flexural strength, Chemistry (miscellaneous), General Materials Science, Composite material, 0210 nano-technology
Abstract: International audience; Spiropyran doped P(VDF-TrFE) nanocomposite films were spray-coated onto silicon micro-cantilevers. We show that switching the molecules from the closed- to the open-ring form by UV light gives rise to a downward bending of the cantilever as well as to a decrease of its resonance frequency. This photoactuation is reversible by means of heating and simultaneous visible light irradiation. From the flexural bending and resonance data, we extracted the actuation strain (0.13 ± 0.03%), stress (4 ± 1 MPa) and elastic energy density (2.3 ± 1 mJ cm−3) associated with the photoisomerization of spiropyran molecules in the composite films.
Published: 2021

27. On the Spin-State Dependence of Redox Potentials of Spin Crossover Complexes

Author: Azzedine Bousseksou, Isabelle M. Dixon, Alix Sournia-Saquet, Sylvain Rat, Lionel Salmon, Gábor Molnár, Laboratoire de Chimie et Physique Quantiques (LCPQ), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse)
Subjects: Electrochemical reduction, Spin states, 010405 organic chemistry, Chemistry, Spin transition, Charge (physics), 010402 general chemistry, 01 natural sciences, Quantum mechanics, 0104 chemical sciences, Inorganic Chemistry, Mathematical methods, Spin crossover, Chemical physics, Oxidation, Molecule, [CHIM]Chemical Sciences, Molecular orbital, Density functional theory, Physical and Theoretical Chemistry, Redox reactions, Spin-½
Abstract: International audience; Resistance switching properties of nanoscale junctions of spin crossover molecules have received recently much interest. In many cases, this property has been traced back to the variation of molecular orbital energies upon spin transition. However, one can also expect a substantial reorganization of the molecular structure due to charge localization, which calls for a better understanding of the relationship between the redox potential and the spin state of the molecule. To investigate this issue, we carried out a detailed density functional theory and variable temperature cyclic voltammetry investigation of the benchmark compound [Fe(HB(1,2,4-triazol-1-yl)3)2] in solution. We show that, for a correct thermodynamical picture, it is necessary to take into account the charge transfer-induced electronic and structural reorganization as well as spin equilibria in the oxidized and reduced species.
Published: 2020

28. Unprecedented switching endurance affords for high-resolution surface temperature mapping using a spin-crossover film

Author: Azzedine Bousseksou, Christian Bergaud, Alin-Ciprian Bas, Lucie Routaboul, Gábor Molnár, Karl Ridier, Yuteng Zhang, Lionel Salmon, Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Équipe Microsystèmes électromécaniques (LAAS-MEMS), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), the European Commission - SPINSWITCH project (H2020-MSCA-RISE-2016, Grant Agreement No. 734322), and China Scholarship Council
Subjects: Work (thermodynamics), Fabrication, Materials science, Science, General Physics and Astronomy, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, 7. Clean energy, Temperature measurement, Characterization and analytical techniques, General Biochemistry, Genetics and Molecular Biology, Article, Spin crossover, Thermal, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Thin film, lcsh:Science, Nanoscopic scale, Multidisciplinary, business.industry, Resolution (electron density), General Chemistry, 021001 nanoscience & nanotechnology, Sensors and biosensors, 0104 chemical sciences, Optoelectronics, lcsh:Q, 0210 nano-technology, business
Abstract: Temperature measurement at the nanoscale is of paramount importance in the fields of nanoscience and nanotechnology, and calls for the development of versatile, high-resolution thermometry techniques. Here, the working principle and quantitative performance of a cost-effective nanothermometer are experimentally demonstrated, using a molecular spin-crossover thin film as a surface temperature sensor, probed optically. We evidence highly reliable thermometric performance (diffraction-limited sub-µm spatial, µs temporal and 1 °C thermal resolution), which stems to a large extent from the unprecedented quality of the vacuum-deposited thin films of the molecular complex [Fe(HB(1,2,4-triazol-1-yl)3)2] used in this work, in terms of fabrication and switching endurance (>107 thermal cycles in ambient air). As such, our results not only afford for a fully-fledged nanothermometry method, but set also a forthcoming stage in spin-crossover research, which has awaited, since the visionary ideas of Olivier Kahn in the 90’s, a real-world, technological application., Developing novel thermometry techniques for nanoscale temperature measurements are vital for realizing efficient thermal management of nanoscale devices. Here, the authors report thermally stable spin-crossover material-based nanothermometers for high-resolution surface temperature mapping.
Published: 2020

29. Visible-Light Acceleration of H

Author: Naixin, Kang, Qi, Wang, Rodrigue, Djeda, Wenjuan, Wang, Fangyu, Fu, Marta Martinez, Moro, Maria de Los Angeles, Ramirez, Sergio, Moya, Emerson, Coy, Lionel, Salmon, Jean-Luc, Pozzo, and Didier, Astruc
Abstract: Production of hydrogen (H
Published: 2020

30. Effect of the spin crossover filler concentration on the performance of composite bilayer actuators

Author: Mario Piedrahita-Bello, Yue Zan, Alejandro Enriquez-Cabrera, Gábor Molnár, Bertrand Tondu, Lionel Salmon, Azzedine Bousseksou, Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Équipe Mouvement des Systèmes Anthropomorphes (LAAS-GEPETTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), and ANR-19-CE09-0008,NAGAM,Actionnement nanomoléculaire pour une nouvelle génération de muscles artificiels(2019)
Subjects: Nanocomposite, Actuator, General Physics and Astronomy, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Physical and Theoretical Chemistry, Spin crossover, Polymer, Computer Science::Other, Automatization
Abstract: International audience; Macroscopic, soft bilayer spin crossover@polymer actuators were fabricated by a blade casting technique using [Fe(NH2trz)3]SO4 spin crossover particles embedded in a P(VDF-TrFE) matrix. Incorporation of silver flakes in the second layer allowed for electro-thermal actuation via Joule heating. The speed and amplitude of the actuator bending movement, resulting from the expansion/contraction of the spin crossover particles on heating/cooling, were tested for different particle concentrations (15, 25, 33 and 50 wt%) under both open- and closed-loop controls. The capability of the actuators to embark charge and to follow a sinusoidal position was also investigated.
Published: 2022

31. Robust linear control of a bending molecular artificial muscle based on spin crossover molecules

Author: Bertrand Tondu, Mario Piedrahita-Bello, Lionel Salmon, Gábor Molnár, Azzedine Bousseksou, Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT), Équipe Mouvement des Systèmes Anthropomorphes (LAAS-GEPETTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Federal University of Toulouse/ Région Occitanie, France, and ANR-19-CE09-0008,NAGAM,Actionnement nanomoléculaire pour une nouvelle génération de muscles artificiels(2019)
Subjects: Metals and Alloys, Artificial muscle, Spin crossover, Condensed Matter Physics, [SPI.AUTO]Engineering Sciences [physics]/Automatic, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Computer Science::Robotics, [CHIM.POLY]Chemical Sciences/Polymers, Open-loop identification, PID control, Electrical and Electronic Engineering, Bending actuator, [SDV.IB.BIO]Life Sciences [q-bio]/Bioengineering/Biomaterials, Instrumentation
Abstract: International audience; Bending actuators represent a popular class of artificial muscles for which efficient closed-loop control is a remarkable challenge, due to the complexity of physico-chemical phenomena occurring during dynamic contraction. In this study, we investigate an electro-thermally actuated, bilayer bending actuator based on spin crossover molecules. While these artificial muscles can open-loop contract in several tens of seconds, we show that a simple closed-loop PID-control is able to reduce the response time to ca. 1.5 s, even with loads up to 5 times the actuator weight (i.e. a maximal load of about 343 mg). We demonstrate also satisfactory sine wave tracking performance. The relevance of this linear control approach applied to a nonlinear actuator is the consequence of the high sensibility of the actuator to the current, responsible for the Joule effect. Notably, the actuator roughly behaves like a second-order linear system, whose time “constants” decrease with current. Consequently, the natural speed improvement peculiar to the PID-controller is further amplified by this nonlinear effect, without any loss in stability of the closed-loop system.
Published: 2022

32. Sequential Activation of Molecular and Macroscopic Spin‐State Switching within the Hysteretic Region Following Pulsed Light Excitation (Adv. Mater. 6/2022)

Author: Karl Ridier, William Nicolazzi, Lionel Salmon, Gábor Molnár, and Azzedine Bousseksou
Subjects: Mechanics of Materials, Mechanical Engineering, General Materials Science
Published: 2022

33. Spin crossover polymer composites, polymers and related soft materials

Author: Azzedine Bousseksou, Lionel Salmon, Amalia Rapakousiou, Gábor Molnár, Mario Piedrahita Bello, Alejandro Enríquez-Cabrera, Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), CONACYT, Occitanie Région, Federal University of Toulouse, and ANR-19-CE09-0008,NAGAM,Actionnement nanomoléculaire pour une nouvelle génération de muscles artificiels(2019)
Subjects: Polymers, Supramolecular chemistry, 010402 general chemistry, 01 natural sciences, Langmuir–Blodgett film, Inorganic Chemistry, Liquid crystal, Spin crossover, Dendrimer, Materials Chemistry, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Physical and Theoretical Chemistry, Alkyl, chemistry.chemical_classification, Quantitative Biology::Biomolecules, 010405 organic chemistry, Polymer, Composite materials, 0104 chemical sciences, Condensed Matter::Soft Condensed Matter, chemistry, Chemical physics, Spin crossover complexes, Artificial muscle, Condensed Matter::Strongly Correlated Electrons, Soft matter
Abstract: International audience; We review the synthesis, properties and applications of spin crossover polymer composites, polymers and some related ‘soft’ materials. These materials have received recently much attention because they provide an efficient way for the processing of spin crossover complexes in various shapes at various size scales and can give rise also to unique physical properties. First, we discuss in detail the state of the art of the elaboration of spin crossover polymer composites, using either inorganic complex precursors in solution or preformed spin crossover powder. A particular attention is paid on the influence of the polymer matrix on the spin crossover properties and on the use of ‘active’ polymers for development of synergies between the properties of the matrix and the load. Polymer composite devices for applications in the fields of artificial muscles, energy harvesting and thermochromic sensors are also highlighted. Then, more recent works, in which organic polymeric chains are used as ligands for the transition metal ions are presented. Finally, we overview various related ‘soft’ spin crossover compounds including spin crossover dendrimers, gels, liquid crystals and Langmuir Blodgett films with particular emphasis on compounds with supramolecular interactions of alkyl chains.
Published: 2020

34. A molecular spin-crossover film allows for wavelength tuning of the resonance of a Fabry–Perot cavity

Author: Victoria Shalabaeva, Azzedine Bousseksou, Yuteng Zhang, Lucie Routaboul, Sylvain Pelloquin, Isabelle Séguy, Stephane Calvez, Gábor Molnár, Karl Ridier, Lionel Salmon, Henri Camon, Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Équipe Matériaux et Procédés pour la Nanoélectronique (LAAS-MPN), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Équipe Photonique (LAAS-PHOTO), CNRS MITI 'CMTS-SLM', Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), and Université de Toulouse (UT)
Subjects: [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Materials science, business.industry, Resonance, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, Wavelength, Spin crossover, Materials Chemistry, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Optoelectronics, Photonics, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, 0210 nano-technology, Absorption (electromagnetic radiation), business, Refractive index, Fabry–Pérot interferometer
Abstract: International audience; We harness the remarkable refractive index switching (0.04 < Δn(λ) < 0.2) between the low-spin and high-spin states of the molecular spin-crossover (SCO) complex [Fe(HB(1,2,4-triazol-1-yl)3)2] to realize a wavelength-tunable Ag/SCO/Ag multilayer Fabry–Perot cavity. This tuneability is coupled with low absorption losses (k ≤ 10−4) between 350 and 1000 nm providing scope for reconfigurable and self-adaptive photonics applications in the visible spectral region.
Published: 2020

35. 4D printing with spin-crossover polymer composites

Author: Bertrand Tondu, Lionel Salmon, José Elias Angulo-Cervera, Mario Piedrahita-Bello, Gábor Molnár, Christophe Thibault, Rémi Courson, Azzedine Bousseksou, Laurent Malaquin, Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Équipe Mouvement des Systèmes Anthropomorphes (LAAS-GEPETTO), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Équipe Microsystèmes électromécaniques (LAAS-MEMS), Service Techniques et Équipements Appliqués à la Microélectronique (LAAS-TEAM), Équipe Ingénierie pour les sciences du vivant (LAAS-ELIA), Federal University of Toulouse/Région Occitanie, CONACYT, FEDER European Regional Funds and Région Occitanie (Grant No. 16007407/MP0011594), European Commission (H2020-MSCA-RISE-2016, SPINSWITCH, No. 734322 and H2020-NMBP-PILOTS-2017, HoliFAB, No. 760927), ANR-19-CE09-0008,NAGAM,Actionnement nanomoléculaire pour une nouvelle génération de muscles artificiels(2019), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), and Université Fédérale Toulouse Midi-Pyrénées
Subjects: chemistry.chemical_classification, Filler (packaging), Materials science, business.industry, Composite number, 3D printing, 02 engineering and technology, General Chemistry, Polymer, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, chemistry, Spin crossover, Materials Chemistry, Polymer composites, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Composite material, 0210 nano-technology, business, 4d printing, Spin-½
Abstract: International audience; A stereolithographic 3D printing method was used to fabricate spin crossover–polymer composite materials with various shapes and sizes (up to several cm). The thermomechanical properties of the polymer and the stiumuli-responsive properties of the filler are preserved in the composite – affording for a new approach of 4D printing.
Published: 2020

36. Spin crossover in Fe(triazole)-Pt nanoparticle self-assembly structured at the sub-5 nm scale

Author: Phillipe Demont, Benedikt Lassalle-Kaiser, José Sánchez Costa, Suhail Usmani, Mirko Mikolasek, Gábor Molnár, Azzedine Bousseksou, Mathilde Rigoulet, Bruno Chaudret, Angélique Gillet, Simon Tricard, Julian Carrey, Lionel Salmon, Laboratoire de physique et chimie des nano-objets (LPCNO), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC), Laboratoire de chimie de coordination (LCC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), Instituto IMDEA Nanociencia [Madrid], Instituto Imdea Nanociencia, Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Centre National de la Recherche Scientifique - CNRS (FRANCE), European Synchrotron Radiation Facility - ESRF (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut National des Sciences Appliquées de Toulouse - INSA (FRANCE), Synchrotron SOLEIL - SSOLEIL (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Universidad Autonoma de Madrid (SPAIN), Centre Interuniversitaire de Recherche et d'Ingénierie des Matériaux - CIRIMAT (Toulouse, France), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT), Marie-Curie research program (NanoSCOpe 328078), Indo-French Centre for the Promotion of Advanced Research - CEFIPRA, Spanish MINECO - National Research Project (CTQ2016-80635-P), Ramon y Cajal Research program (RYC-2014-16866), ANR-10-LABX-0037,NEXT,Nano, EXtreme Measurements & Theory(2010), ANR-18-CE09-0007,MOSC,Chimie supraparticulaire orientée par des molécules(2018), ANR-13-BS07-0020,NanoHybrid,Nanostructures hybrides bistables(2013), and ANR-17-EURE-0009,NanoX,Science et Ingénierie à l'Echelle Nano(2017)
Subjects: Materials science, Matériaux, Population, Infrared spectroscopy, Nanoparticle, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, [CHIM.GENI]Chemical Sciences/Chemical engineering, Spin crossover, Molecule, Génie chimique, General Materials Science, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, education, Génie des procédés, Molecular switch, education.field_of_study, Molecular electronics, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Chemical physics, Self-assembly, 0210 nano-technology
Abstract: International audience; A main goal of molecular electronics is to relate the performance of devices to the structure and electronic state of molecules. Among the variety of possibilities that organic, organometallic and coordination chemistries offer to tune the energy levels of molecular components, spin crossover phenomenon is a perfect candidate for elaboration of molecular switches. The reorganization of the electronic state population of the molecules associated to the spin crossover can indeed lead to a significant change in conductivity. However, molecular spin crossover is very sensitive to the environment and can disappear once the molecules are integrated into devices. Here, we show that the association of ultra-small 1.2 nm platinum nanoparticles with FeII triazole-based spin crossover coordination polymers leads to self-assemblies, extremely well organized at the sub-3 nm scale. The quasi-perfect alignment of nanoparticles observed by transmission electron microscopy, in addition to specific signature in infrared spectroscopy, demonstrates the coordination of the long-chain molecules with the nanoparticles. Spin crossover is confirmed in such assemblies by X-ray absorption spectroscopic measurements and shows unambiguous characteristics both in magnetic and charge transport measurements. Coordinating polymers are therefore ideal candidates for the elaboration of robust, well-organized, hybrid self-assemblies with metallic nanoparticles, while maintaining sensitive functional properties, such as spin crossover.
Published: 2020

37. Ligand substitution effects on the charge transport properties of the spin crossover complex [Fe(Htrz)1+y−x (trz)2−y (NH2trz) x ](BF4)y·nH2O

Author: Aurelian Rotaru, Ionela Rusu, Gábor Molnár, Azzedine Bousseksou, Mario Piedrahita-Bello, Lionel Salmon, Philippe Demont, Ion Soroceanu, Simona-Lacramioara Lupu, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Universitatea Stefan cel Mare Suceava - USU (ROMANIA), Laboratoire de Chimie de Coordination - LCC (Toulouse, France), MANSiD Research Center [Suceava], Universitatea Stefan cel Mare Suceava (USU), Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), European Commission - SPINSWITCH project (H2020-MSCA-RISE-2016, Grant Agreement No. 734322), Federal Univeristy of Toulouse and the Occitanie Region, and EXCALIBUR project (Contract No. 18 PFE/16.10.2018)
Subjects: Permittivity, Materials science, Spin states, Matériaux, 02 engineering and technology, Dielectric, Conductivity, 01 natural sciences, Broad-band dielectric spectroscopy, [SPI.MAT]Engineering Sciences [physics]/Materials, symbols.namesake, Spin crossover, 0103 physical sciences, General Materials Science, 010306 general physics, Debye model, Phase transition, Hysteresis, Relaxation (NMR), 021001 nanoscience & nanotechnology, Condensed Matter Physics, Molecular switches, Dipole, Crystallography, symbols, Charge transport properties, 0210 nano-technology
Abstract: International audience; The complex dielectric permittivity of a series of spin crossover complexes, with variable ligand stoichiometry [Fe(Htrz)1+y−x (trz)2−y (NH2trz) x ](BF4) y centerdotnH2O, has been investigated as a function of temperature in a wide frequency range. In each compound, a substantial drop of the conductivity and permittivity is evidenced when going from the low spin to the high spin state, albeit with decreasing amplitude for increasing ligand substitution (i.e. for increasing x). The deconvolution of the dielectric spectra using the Havriliak–Negami equation allowed to extract the dipole and conductivity relaxation times, their distributions as well as the dielectric strengths in both spin states. Remarkably, no clear correlation appears between the conductivity changes and the lattice properties (Debye temperature) in the dilution series. We rationalize these results by considering the dimensionality of the system (1D), wherein the charge transport occurs most likely by hopping along the [Fe(Rtrz)3] n n+ chains.
Published: 2020

38. Ligand substitution effects on the charge transport properties of the spin crossover complex [Fe(Htrz)

Author: Ion, Soroceanu, Simona-Lacramioara, Lupu, Ionela, Rusu, Mario, Piedrahita-Bello, Lionel, Salmon, Gábor, Molnár, Philippe, Demont, Azzedine, Bousseksou, and Aurelian, Rotaru
Abstract: The complex dielectric permittivity of a series of spin crossover complexes, with variable ligand stoichiometry [Fe(Htrz)
Published: 2020

39. Resistance Switching in Large-Area Vertical Junctions of the Molecular Spin Crossover Complex [Fe(HB(tz) 3 ) 2 ]: ON/OFF Ratios and Device Stability

Author: Azzedine Bousseksou, Isabelle Séguy, Aurelian Rotaru, Yuteng Zhang, Lionel Salmon, Mario Piedrahita-Bello, Victoria Shalabaeva, Gábor Molnár, Karl Ridier, Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Équipe Matériaux et Procédés pour la Nanoélectronique (LAAS-MPN), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), University Stefan cel Mare of Suceava (USU), SPINSWITCH project (H2020-MSCA-RISE-2016, Grant Agreement No. 734322), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Équipe MICrosystèmes d'Analyse (LAAS-MICA), Université Toulouse 1 Capitole (UT1)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse 1 Capitole (UT1)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), MANSiD Research Center [Suceava], and Universitatea Stefan cel Mare Suceava (USU)
Subjects: Materials science, Condensed matter physics, Spin states, Charge (physics), Device Properties, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Stability (probability), Cathode, law.invention, multilayer junctions, spin crossover, Spin crossover, law, 0103 physical sciences, Electrode, General Materials Science, [CHIM.COOR]Chemical Sciences/Coordination chemistry, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, 010306 general physics, 0210 nano-technology, Layer (electronics), resistance switching
Abstract: International audience; Multilayer crossbar junctions composed of ITO/[Fe(HB(1,2,4-triazol-1-yl)3)2]/M (with M = Al or Ca) were fabricated and investigated for their resistance switching properties. Current–voltage–temperature maps revealed ON/OFF resistance ratios as high as 400, with the ON and OFF states defined, respectively, as the low-resistance, low spin state and the high-resistance, high spin state of the spin crossover layer. Similar results were obtained with Al and Ca cathodes indicating that the charge transport in the insulating spin crossover film is at the origin of the resistance switching instead of electron injection at the electrodes. The reproducibility and stability of the device properties were also studied.
Published: 2020

40. Resistance switching in large-area vertical junctions of the molecular spin crossover complex [Fe(HB(tz)

Author: Yuteng, Zhang, Isabelle, Séguy, Karl, Ridier, Victoria, Shalabaeva, Mario, Piedrahita-Bello, Aurelian, Rotaru, Lionel, Salmon, Gábor, Molnár, and Azzedine, Bousseksou
Abstract: Multilayer crossbar junctions composed of ITO/[Fe(HB(1,2,4-triazol-1-yl)
Published: 2020

41. Mechano-electric coupling in P(VDF–TrFE)/spin crossover composites

Author: Azzedine Bousseksou, Philippe Demont, Mario Piedrahita-Bello, Baptiste Martin, Gábor Molnár, Lionel Salmon, Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), European Commission (H2020-MSCA-RISE-2016, SPINSWITCH, No. 734322), Federal University of Toulouse/Occitanie Région, and ANR-19-CE09-0008,NAGAM,Actionnement nanomoléculaire pour une nouvelle génération de muscles artificiels(2019)
Subjects: Materials science, Matériaux, Spin transition, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 7. Clean energy, Ferroelectricity, Piezoelectricity, 0104 chemical sciences, Pyroelectricity, [SPI.MAT]Engineering Sciences [physics]/Materials, Differential scanning calorimetry, [CHIM.GENI]Chemical Sciences/Chemical engineering, Spin crossover, Materials Chemistry, Electroactive polymers, Curie temperature, Génie chimique, Composite material, 0210 nano-technology, Spin crossover composites
Abstract: Spin crossover particles dispersed in a piezo/ferroelectric poly(vinylidene fluoride-co-trifluoro-ethylene), P(VDF–TrFE), matrix give rise to inspiring mechano-electric phenomena, with possible applications for energy harvesting and sensing. Particles of different chemical compositions, morphologies and concentrations were loaded into copolymers with different TrFE molar contents to investigate the effect of these parameters on the mechano-electric coupling between the polymer and the spin crossover material. The samples were characterized by elemental analysis, powder X-ray diffraction, Raman spectroscopy, optical reflectivity, differential scanning calorimetry, and electron microscopy and were studied also for their piezo/pyroelectric properties. We show that it is possible to tune simultaneously the spin transition temperature of the particles and the Curie temperature of the matrix in such a way that the piezoelectric effect from the spin transition and the pyroelectric response of the polymer can be concomitantly observed. This result provides prospects for the development of smart, multifunctional electroactive polymer composites and for increasing their thermal–electrical harvester output.
Published: 2020

42. Heat Capacity and Thermal Damping Properties of Spin‐Crossover Molecules: A New Look at an Old Topic

Author: Carlos M. Quintero, Gábor Molnár, Karl Ridier, Azzedine Bousseksou, Mario Piedrahita-Bello, Yuteng Zhang, Christian Bergaud, Lionel Salmon, Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Équipe Microsystèmes électromécaniques (LAAS-MEMS), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), and Université de Toulouse (UT)
Subjects: Materials science, Spin transition, 02 engineering and technology, 010402 general chemistry, Thermal energy storage, 01 natural sciences, 7. Clean energy, Heat capacity, Transition metal, Spin crossover, Thermal, Molecular film, Molecular thin films, General Materials Science, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Spin-crossover, Condensed matter physics, business.industry, Mechanical Engineering, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Excess heat capacity, Mechanics of Materials, Thermal management, 0210 nano-technology, business, Thermal energy
Abstract: International audience; The thermally induced spin-crossover (SCO) phenomenon in transition metal complexes is an entropy-driven process, which has been extensively studied through calorimetric methods. Yet, the excess heat capacity associated with the molecular spin-state switching has never been explored for practical applications. Herein, the thermal damping effect of an SCO film is experimentally assessed by monitoring the transient heating response of SCO-coated metallic microwires, Joule-heated by current pulses. A damping of the wire temperature, up to 10%, is evidenced on a time scale of tens of microseconds due to the spin-state switching of the molecular film. Fast heat-charging dynamics and negligible fatigability are demonstrated, which, together with the solid-solid nature of the spin transition, appear as promising features for achieving thermal energy management applications in functional devices.
Published: 2020

43. Visible-Light Acceleration of H 2 Evolution from Aqueous Solutions of Inorganic Hydrides Catalyzed by Gold-Transition-Metal Nanoalloys

Author: Didier Astruc, Marta Martinez Moro, Wenjuan Wang, Rodrigue Djeda, Qi Wang, Sergio Moya, Maria de los Angeles Ramirez, Lionel Salmon, Naixin Kang, Fangyu Fu, Emerson Coy, Jean-Luc Pozzo, Institut des Sciences Moléculaires (ISM), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), CIC BiomaGUNE [Espagne], Universidad Nacional de San Martin (UNSAM), Adam Mickiewicz University in Poznań (UAM), Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1 (UB)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), China Scholarship Council (CSC), National Science Centre of Poland - program OPUS, Centre National de la Recherche Scientifique (CNRS), and University of Bordeaux
Subjects: Materials science, Hydrogen, chemistry.chemical_element, 02 engineering and technology, [CHIM.INOR]Chemical Sciences/Inorganic chemistry, 010402 general chemistry, Photochemistry, 7. Clean energy, 01 natural sciences, Catalysis, Metal, Transition metal, Electromagnetic radiation, Alloys, General Materials Science, Hydrogen production, Aqueous solution, Hydrolysis, [CHIM.CATA]Chemical Sciences/Catalysis, 021001 nanoscience & nanotechnology, Oxidative addition, Nanomaterial-based catalyst, 0104 chemical sciences, chemistry, 13. Climate action, visual_art, visual_art.visual_art_medium, Irradiation, Gold, 0210 nano-technology
Abstract: International audience; Production of hydrogen (H2) upon hydrolysis of inorganic hydrides potentially is a key step in green energy production. We find that visible-light irradiation of aqueous solutions of ammonia-borane (AB) or NaBH4 containing “click”-dendrimer-stabilized alloyed nanocatalysts composed of nanogold and another late transition-metal nanoparticle (LTMNP) highly enhances catalytic activity for H2 generation while also inducing alloy to Au core@M shell nanocatalyst restructuration. In terms of visible-light-induced acceleration of H2 production from both AB and NaBH4, the Au1Ru1 alloy catalysts show the most significant light-boosting effect. Au–Rh and Au–PtNPs are also remarkable with total H2 release time from AB and NaBH4 down to 1.3 min at 25 °C (AuRh), 3 times less than in the dark, and Co is the best earth-abundant metal alloyed with nanogold. This boosting effect is explained by the transfer of plasmon-induced hot electron from the Au atoms to the LTMNP atoms facilitating water O–H oxidative addition on the LTMNP surface, as shown by the large primary kinetic isotope effect kH/kD upon using D2O obtained for both AB and NaBH4. The second simultaneous and progressive effect of visible-light irradiation during these reactions, alloy to Au core@M shell restructuration, enhances the catalytic activity in the recycling, because, in the resulting Au core@M shell, the surface metal (such as Ru) is much more active than the original Au-containing alloy surface in dark reactions. There is no light effect on the rate of hydrogen production for the recycled nanocatalyst because of the absence of Au on the NP surface, but it is still very efficient in hydrogen release during four cycles because of the initial light-induced restructuration, although it is slightly less efficient than the original nanoalloy in the presence of light. The dendritic triazole coordination on each LTMNP surface appears to play a key role in these remarkable light-induced processes.
Published: 2020

44. Broad-Band Dielectric Spectroscopy Reveals Peak Values of Conductivity and Permittivity Switching upon Spin Crossover

Author: Azzedine Bousseksou, Philippe Demont, Adrian Graur, Ion Soroceanu, Eugen Coca, Lionel Salmon, Aurelian Rotaru, Gábor Molnár, Universitatea Stefan cel Mare Suceava - USU (ROMANIA), Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Laboratoire de Chimie de Coordination - LCC (Toulouse, France), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), European Commission - SPINSWITCH project (H2020-MSCA-RISE-2016, Grant Agreement No. 734322), EXCALIBUR project (Contract No. 18 PFE/16.10.2018), and Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)
Subjects: Permittivity, Materials science, Dielectric strength, Condensed matter physics, Spin states, Matériaux, Physics::Optics, 02 engineering and technology, Dielectric, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Broad-band dielectric spectroscopy, 0104 chemical sciences, Dielectric spectroscopy, [SPI.MAT]Engineering Sciences [physics]/Materials, Dipole, Spin crossover, Relaxation (physics), General Materials Science, Spin Crossover, Physical and Theoretical Chemistry, 0210 nano-technology
Abstract: We use broad-band dielectric spectroscopy to investigate the spin-state dependence of electrical properties of the [Fe(Htrz)2(trz)](BF4) spin crossover complex. We show that the Havriliak–Negami theory can fully describe the variation of the complex dielectric permittivity of the material across the pressure–temperature phase diagram. The analysis reveals three dielectric relaxation processes, which we attribute to electrode/interface polarization, dipole relaxation, and charge transport relaxation. The contribution of the latter appears significant to the dielectric strength. Remarkably, the permittivity and conductivity changes between the high spin and low spin states are amplified at the corresponding relaxation frequencies.
Published: 2019

45. Unprecedented Size Effect on the Phase Stability of Molecular Thin Films Displaying a Spin Transition

Author: Mirko Mikolasek, William Nicolazzi, Victoria Shalabaeva, Alin-Ciprian Bas, Lionel Salmon, Gábor Molnár, Sylvain Rat, Azzedine Bousseksou, Maria Dolores Manrique-Juarez, Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, and European Synchrotron Radiation Facility (ESRF)
Subjects: Materials science, Condensed matter physics, Continuum mechanics, Strain (chemistry), Phase stability, Spin transition, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Surface energy, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, General Energy, Phase (matter), [CHIM.COOR]Chemical Sciences/Coordination chemistry, Physical and Theoretical Chemistry, Thin film, 0210 nano-technology, Anisotropy
Abstract: International audience; An unexpected upshift of the spin transition temperature by ca. 3 K is observed in thermally evaporated films of the [FeII(HB(tz)3)2] (tz = 1,2,4-triazol-1-yl) complex when reducing the film thickness from ca. 200 to 45 nm. Fitting the experimental data to continuum mechanics and thermodynamical models allows us to propose an explanation based on the anisotropy of the transformation strain leading to ∼5 mJ/m2 higher 00l surface energy in the high-spin phase.
Published: 2017

46. Pegylated interferon alfa-2b vs standard interferon alfa-2b, plus ribavirin, for chronic hepatitis C in HIV-infected patients

Author: Carrat, Fabrice, Bani-Sadr, Firouze, Pol, Stanislas, Rosenthal, Eric, Lunel-Fabiani, Francoise, Benzekri, Asmae, Perronne, Christian, Cacoub, Patrice, Morand, Patrice, Goujard, Cecile, Degott, Claude, Lionel Salmon-Ceron, Dominique, and Pialouz, Gilles
Subjects: Hepatitis C -- Drug therapy, Ribavirin -- Dosage and administration, HIV infection -- Drug therapy
Abstract: The study conducted to investigate the safety and efficacy of peginterferon alfa-2b plus ribavirin against standard interferon alfa-2b plus ribavirin in HIV-HCV (hepatitis C virus) coinfected patients is presented. It is found that in combination with ribavirin, treatment with peginteferon alfa-2b is more effective than standard interferon alfa-2b for HCV infection in HIV-infected patients.
Published: 2004

47. A Bistable Microelectromechanical System Actuated by Spin-Crossover Molecules

Author: Azzedine Bousseksou, Gábor Molnár, Jean Cacheux, Sylvain Rat, Lionel Salmon, Fabrice Mathieu, Liviu Nicu, Maria Dolores Manrique-Juarez, Thierry Leichle, Victoria Shalabaeva, Équipe Microsystèmes électromécaniques (LAAS-MEMS), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Service Instrumentation Conception Caractérisation (LAAS-I2C), Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), and Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Cantilever, Bistability, Silicon, Spin transition, chemistry.chemical_element, Nanotechnology, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Catalysis, Ion, Spin crossover, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, Microelectromechanical systems, business.industry, General Chemistry, General Medicine, 021001 nanoscience & nanotechnology, Piezoresistive effect, Computer Science::Other, 0104 chemical sciences, chemistry, Optoelectronics, business, 0210 nano-technology
Abstract: International audience; We report on a bistable MEMS device actuated by spin-crossover molecules. The device consists of a freestanding silicon microcantilever with an integrated piezoresistive detection system, which was coated with a 140 nm thick film of the [Fe(HB(tz)3)2] (tz=1,2,4-triazol-1-yl) molecular spin-crossover complex. Switching from the low-spin to the high-spin state of the ferrous ions at 338 K led to a reversible upward bending of the cantilever in agreement with the change in the lattice parameters of the complex. The strong mechanical coupling was also evidenced by the decrease of approximately 66 Hz in the resonance frequency in the high-spin state as well as by the drop in the quality factor around the spin transition.
Published: 2017

48. RhAg/rGO nanocatalyst: ligand-controlled synthesis and superior catalytic performances for the reduction of 4-nitrophenol

Author: Lionel Salmon, Didier Astruc, Luis Yate, Sergio Moya, Changlong Wang, Jaime Ruiz, Roberto Ciganda, Institut des Sciences Moléculaires (ISM), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Université Sciences et Technologies - Bordeaux 1-Université Montesquieu - Bordeaux 4-Institut de Chimie du CNRS (INC), Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Facultad de Quimica de San Sebastian, Universidad del Pais Vasco, Universidad del Pais Vasco / Euskal Herriko Unibertsitatea [Espagne] (UPV/EHU), CIC BiomaGUNE, and CIC BiomaGUNE [Espagne]
Subjects: Materials science, Inorganic chemistry, Nanoparticle, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, law.invention, Catalysis, chemistry.chemical_compound, law, [CHIM.COOR]Chemical Sciences/Coordination chemistry, General Materials Science, High-resolution transmission electron microscopy, Bimetallic strip, Nanocomposite, biology, Graphene, Mechanical Engineering, 4-Nitrophenol, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Chemical engineering, chemistry, Mechanics of Materials, RHAG, biology.protein, 0210 nano-technology
Abstract: The design of ultrafine, highly efficient and recyclable heterogeneous bimetallic nanoparticles catalysts is challenging. In this work, we report for the first time the preparation of ultrafine and monodispersed bimetallic RhAg nanoparticles that are uniformly supported on reduced graphene oxide (rGO) nanosheets (RhAg/rGO). A key is the presence of the tris(triazolyl)-polyethylene glycol (tristrz-PEG) ligand as a weak stabilizing agent. This amphiphilic tridentate ligand not only enables the formation of ultrafine RhAg NPs, but also allows quantitative fixation of the NPs onto the rGO, which avoids metal loss and further improves catalytic efficiency. The RhAg/rGO catalysts were characterized by various techniques including UV–Vis, ICP-AES, TEM, HRTEM, STEM, EDX and XPS. By varying the molar ratios of Rh to Ag, the highest catalytic activity in the reduction of 4-nitrophenol by NaBH4 was obtained for RhAg0.5/rGO with a remarkable reaction rate of k app = 14.8 × 10−3 s−1 (k nor = 1415 s−1 g−1). Moreover, the catalyst was recycled, and its amount was reduced to 100 ppm of RhAg0.5/rGO while retaining an exceptional catalytic efficiency. The present work contributes to the effective design of ultrafine bimetallic NPs/graphene-based nanocomposites and to the fabrication of very efficient and cost-effective catalysts.
Published: 2017

49. Solvatomorphism and structural-spin crossover property relationship in bis[hydrotris(1,2,4-triazol-1-yl)borate]iron(<scp>ii</scp>)

Author: Gábor Molnár, Karl Ridier, Sylvain Rat, Azzedine Bousseksou, Lionel Salmon, Laure Vendier, Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées
Subjects: Spin states, Chemistry, Spin transition, 02 engineering and technology, General Chemistry, Crystal structure, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Magnetic susceptibility, 0104 chemical sciences, Bond length, Crystallography, Spin crossover, [CHIM.COOR]Chemical Sciences/Coordination chemistry, General Materials Science, Orthorhombic crystal system, Isostructural, 0210 nano-technology
Abstract: International audience; Two solvatomorphs of the mononuclear bis[hydrotris(1,2,4-triazol-1-yl) borate] iron(II) complex, [Fe(HB(tz)(3))(2)] (1) and [Fe(HB(tz)(3))(2)]center dot 6H(2)O (1 center dot 6H(2)O), were obtained by modifying the nature of the crystallization solvent. The crystal structure, thermal stability and spin crossover properties of the crystals and associated bulk powder samples were analysed using variable-temperature single-crystal and powder X-ray diffraction, thermogravimetry, calorimetry, and Raman and Fe-57 Mossbauer spectroscopy as well as by means of magnetic susceptibility and optical microscopy measurements. The orthorhombic (Cmca) solvatomorph 1 center dot 6H(2)O loses water between ca. 323-353 K, leading to the disintegration of the crystals into the polycrystalline sample 1. The solvent-free crystals of 1 crystallize in the orthorhombic space group Pbca with half a complex molecule in the asymmetric unit. They exhibit a remarkably abrupt phase transition around 334 K between the high spin and low spin states. This (isostructural) spin transition is accompanied by a nearly isotropic change of the Fe-II -N bond lengths (8.3 perpendicular to 0.5%) and a highly anisotropic unit cell volume change (4.6 +/- 0.1%). The very high cooperativity of the spin transition in 1 (Gamma = 5700 +/- 50 J mol(-1)) is rather unusual in mononuclear SCO compounds. This property can be related to the relatively high stiffness of the lattice (Debye temperature theta(D) = 198 +/- 2 K), which involves numerous C-H center dot center dot center dot N hydrogen contacts between each molecule with fourteen neighboring molecules.
Published: 2017

50. Effects of solvent vapor annealing on the crystallinity and spin crossover properties of thin films of [Fe(HB(tz)3)2]

Author: Victoria Shalabaeva, Azzedine Bousseksou, Lucie Routaboul, Christophe Thibault, Gábor Molnár, Alin-Ciprian Bas, Xavier Thompson, Laure Vendier, Lionel Salmon, Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Équipe Ingénierie pour les sciences du vivant (LAAS-ELIA), Laboratoire d'analyse et d'architecture des systèmes (LAAS), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées, Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT), European Commission - SPINSWITCH project (H2020-MSCA-RISE-2016, Grant Agreement No. 734322), Région Occitanie (no. 15050123), EMERGENCE@INC208 project, and Louisiana State University LSAMP International Research Experience Project for Undergraduates (NSF Grant no. 1560390)
Subjects: UV-vis spectroscopy, Materials science, 010405 organic chemistry, Annealing (metallurgy), General Chemical Engineering, Analytical chemistry, Spin transition, Recrystallization (metallurgy), Spin crossover complex, General Chemistry, Solvent vapor annealing, 010402 general chemistry, 01 natural sciences, 0104 chemical sciences, law.invention, X-ray diffraction, Solvent, Crystallinity, law, Spin crossover, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Thin film, Crystallization, Thin films Crystallinity
Abstract: We investigated the solvent vapor annealing process of thermally evaporated thin films of the [FeII(HB(tz)3)2] (tz ¼ 1,2,4-triazol-1-yl) spin crossover complex. Using grazing inci- dence X-ray diffraction, atomic force microscopy, and variable-temperature UV spectro- photometry, we show how the crystallinity, morphology, and spin crossover properties of the resulting films are altered by exposure to vapors of five different solvents: diethyl ether, acetone, dichloromethane, ethanol, and water. Remarkably, most solvents yielded highly oriented crystalline films displaying an abrupt and complete spin transition around 336 K. A notable exception is the case of dichloromethanedsuggesting that the solvent ability to accept hydrogen bonding might be a key factor in controlling the film crystal- linity. On the other hand, only water vapor treatment affords for smooth and continuous film morphology. The recrystallization process in controlled humidity was thus followed in situ by monitoring the UV absorbance of the films. This study revealed the critical importance of the relative humidity (RH): for values above a threshold of ca. 72% RH (at 298 K) a very fast (seconds) crystallization occurs leading to robust, crystalline films, whereas crystallization at lower RH values is slower (hours) and leads to less stable, semicrystalline films displaying incomplete spin transitions.
Published: 2019

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