14 results on '"Meera Mohankumar"'
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2. Evaluation of Mg[B(HFIP)
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Ben, Dlugatch, Meera, Mohankumar, Ran, Attias, Balasubramoniam Murali, Krishna, Yuval, Elias, Yosef, Gofer, David, Zitoun, and Doron, Aurbach
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One of the greatest challenges toward rechargeable magnesium batteries is the development of noncorrosive electrolyte solutions with high anodic stability that can support reversible Mg deposition/dissolution. In the last few years, magnesium electrolyte solutions based on Cl-free fluorinated alkoxyborates were investigated for Mg batteries due to their high anodic stability and ionic conductivity and the possibility of reversible deposition/dissolution in ethereal solvents. Here, the electrochemical performance of Mg[B(hexafluoroisopropanol)
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- 2021
3. Site‐Engineered Tetragonal ZrO 2 Nanoparticles: A Promising Oxygen Reduction Catalyst with High Activity and Chemical Stability in Alkaline Medium
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Vineesh Thazhe Veettil, Meera Mohankumar, and David Zitoun
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Mechanics of Materials ,Mechanical Engineering - Published
- 2022
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4. Oxacycle-Fused [1]Benzothieno[3,2‐b][1]benzothiophene Derivatives: Synthesis, Electronic Structure, Electrochemical Properties, Ionisation Potential, and Crystal Structure
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Paolo Samori, Meera Mohankumar, Olivier James Fenwick, Jérôme Cornil, Lionel Sanguinet, Vincent Lemaur, Alan R. Kennedy, Basab Chattopadhyay, Rachid Hadji, Yves Geerts, Laboratoire de Chimie des Polymères, Université libre de Bruxelles (ULB), MOLTECH-Anjou, Université d'Angers (UA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), University of Strathclyde [Glasgow], Laboratoire de Chimie des Matériaux Nouveaux, Université de Mons (UMons), Institut de Science et d'ingénierie supramoléculaires (ISIS), Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Matériaux et nanosciences d'Alsace (FMNGE), and Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)
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arenes ,π-conjugation ,Heteroatom ,Ether ,Crystal structure ,010402 general chemistry ,Crystal engineering ,01 natural sciences ,Methylenedioxy ,chemistry.chemical_compound ,Chimie ,Molecule ,QD ,Ethylenedioxy ,010405 organic chemistry ,Chemistry ,Benzothiophene ,Métallurgie ,General Chemistry ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Combinatorial chemistry ,0104 chemical sciences ,3. Good health ,electrochemistry ,crystal engineering ,electronic properties - Abstract
The molecular properties of [1]benzothieno[3,2-b][1]benzothiophene (BTBT) are vulnerable to structural modifications, which in turn are determined by the functionalization of the backbone. Hence versatile synthetic strategies are needed to discover the properties of this molecule. To address this, we have attempted heteroatom (oxygen) functionalization of BTBT by a concise and easily scalable synthesis. Fourfold hydroxy-substituted BTBT is the key intermediate, from which the compounds 2,3,7,8-bis(ethylenedioxy)-[1]benzothieno[3,2-b][1]benzothiophene and 2,3,7,8-bis(methylenedioxy)-[1]benzothieno[3,2-b][1]benzothiophene are synthesized. The difference in ether functionalities on the BTBT scaffold influences the ionisation potential values substantially. The crystal structure reveals the transformation of the herringbone motif in bare BTBT towards π-stacked columns in the newly synthesized derivatives. The results are further justified by the simulated HOMO levels of the model compound., SCOPUS: ar.j, info:eu-repo/semantics/published
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- 2018
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5. Heteroleptic Copper(I) Complexes Prepared from Phenanthroline and Bis-Phosphine Ligands: Rationalization of the Photophysical and Electrochemical Properties
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John Mohanraj, Meera Mohankumar, Iwona Nierengarten, Michel Holler, Béatrice Delavaux-Nicot, Alix Sournia-Saquet, Jean-François Nierengarten, Nicola Armaroli, Filippo Monti, Enrico Leoni, Leoni, E., Mohanraj, J., Holler, M., Mohankumar, M., Nierengarten, I., Monti, F., Sournia-Saquet, A., Delavaux-Nicot, B., Jean-Francois, Nierengarten, Armaroli, N., Leoni, Enrico, Mohanraj, John, Holler, Michel, Mohankumar, Meera, Nierengarten, Iwona, Monti, Filippo, Sournia-Saquet, Alix, Delavaux-Nicot, Béatrice, Jean-Francois Nierengarten, null, Armaroli, Nicola, Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), Consiglio Nazionale delle Ricerche (CNR), Laboratoire de chimie moléculaire (LCM), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), 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), 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)
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Cu(I) complexes ,Luminescence ,Absorption spectroscopy ,010405 organic chemistry ,Phenanthroline ,Excited states ,chemistry.chemical_element ,Ether ,Crystal structure ,010402 general chemistry ,Electrochemistry ,01 natural sciences ,Medicinal chemistry ,Copper ,0104 chemical sciences ,3. Good health ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Density functional theory ,[CHIM.COOR]Chemical Sciences/Coordination chemistry ,Physical and Theoretical Chemistry ,Phosphine - Abstract
The electronic and structural properties of ten heteroleptic [Cu(NN)(PP)]+ complexes have been investigated. NN indicates 1,10-phenanthroline (phen) or 4,7-diphenyl-1,10-phenanthroline (Bphen); each of these ligands is combined with five PP bis-phosphine chelators, i.e., bis(diphenylphosphino)methane (dppm), 1,2-bis(diphenylphosphino)ethane (dppe), 1,3-bis(diphenylphosphino)propane (dppp), 1,2-bis(diphenylphosphino)benzene (dppb), and bis[(2-diphenylphosphino)phenyl] ether (POP). All complexes are mononuclear, apart from those based on dppm, which are dinuclear. Experimental data - also taken from the literature and including electrochemical properties, X-ray crystal structures, UV-vis absorption spectra in CH2Cl2, luminescence spectra and lifetimes in solution, in PMMA, and as powders - have been rationalized with the support of density functional theory calculations. Temperature dependent studies (78-358 K) have been performed for selected complexes to assess thermally activated delayed fluorescence. The main findings are (i) dependence of the ground-state geometry on the crystallization conditions, with the same complex often yielding different crystal structures; (ii) simple model compounds with imposed C2v symmetry ([Cu(phen)(PX3)2]+ X = H or CH3) are capable of modeling structural parameters as a function of the P-Cu-P bite angle, which plays a key role in dictating the overall structure of [Cu(NN)(PP)]+ complexes; (iii) as the P-Cu-P angle increases, the energy of the metal-to-ligand charge transfer absorption bands linearly increases; (iv) the former correlation does not hold for emission spectra, which are red-shifted for the weaker luminophores; (v) the larger the number of intramolecular π-interactions within the complex in the ground state, the higher the luminescence quantum yield, underpinning a geometry locking effect that limits the structural flattening of the excited state. This work provides a general framework to rationalize the structure-property relationships of [Cu(NN)(PP)]+, a class of compounds of increasing relevance for electroluminescent devices, photoredox catalysis, and solar-to-fuels conversion, which so far have been investigated in an unsystematic fashion, eluding a comprehensive understanding. © Copyright 2018 American Chemical Society.
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- 2018
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6. Heteroleptic copper(I) pseudorotaxanes incorporating macrocyclic phenanthroline ligands of different sizes
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Nicola Armaroli, Joanna M. Malicka, Meera Mohankumar, Jean-Pierre Sauvage, Michel Holler, Béatrice Delavaux-Nicot, Elisa Bandini, Eric Meichsner, Massimo Cocchi, Jean-François Nierengarten, Enrico Leoni, Filippo Monti, Frédéric Niess, Laboratoire de chimie moléculaire (LCM), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Science et d'ingénierie supramoléculaires (ISIS), Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), 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), Istituto per la Sintesi Organica e la Fotoreattività (ISOF-CNR), Consiglio Nazionale delle Ricerche (CNR), Laboratorio Tecnologie dei Materiali Faenza, ENEA, Agenzia Nazionale per le nuove Tecnologie, l’energia e lo sviluppo economico sostenibile (ENEA), Laboratory for Micro and Submicro Enabling Technologies of the Emilia-Romagna Region (MIST E-R), Università degli Studi di Ferrara (UniFE), Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche [Roma] (CNR), Mohankumar, Meera, Holler, Michel, Meichsner, Eric, Nierengarten, Jean-François, Niess, Frédéric, Sauvage, Jean-Pierre, Delavaux-Nicot, Béatrice, Leoni, Enrico, Monti, Filippo, Malicka, Joanna M., Cocchi, Massimo, Bandini, Elisa, Armaroli, Nicola, Mohankumar, M., Holler, M., Meichsner, E., Nierengarten, J. -F., Niess, F., Sauvage, J. -P., Delavaux-Nicot, B., Leoni, E., Monti, F., Malicka, J. M., Cocchi, M., Bandini, E., and Armaroli, N.
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Photoluminescence ,oled ,Rotaxanes ,Phenanthroline ,chemistry.chemical_element ,Ether ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Catalysis ,Catalysi ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,luminescence ,[CHIM.COOR]Chemical Sciences/Coordination chemistry ,Methyl methacrylate ,Cu(I) complexes ,010405 organic chemistry ,Chemistry (all) ,General Chemistry ,Copper ,0104 chemical sciences ,3. Good health ,Crystallography ,chemistry ,Macrocyclic ligand ,Absorption (chemistry) ,Luminescence - Abstract
International audience; A series of copper(I) pseudorotaxanes has been prepared from bis[2-(diphenylphosphino)phenyl] ether (POP) and macrocyclic phenanthroline ligands with different ring sizes (m30, m37, and m42). Variable-temperature studies carried out on the resulting [Cu(mXX)(POP)]+ (mXX = m30, m37, and m42) derivatives have revealed a dynamic conformational equilibrium due to the folding of the macrocyclic ligand. The absorption and luminescence properties of the pseudorotaxanes have been investigated in CH2Cl2. They exhibit metal-to-ligand charge-transfer emission with photoluminescence quantum yields (PLQYs) in the range 20–30%. The smallest system [Cu(m30)(POP)]+ shows minimal differences in spectral shape and position compared to its analogues, suggesting a slightly distorted coordination environment. PLQY is substantially enhanced in poly(methyl methacrylate) films (∼40−45%). The study of emission spectra and excited-state lifetimes in powder samples as a function of temperature (78–338 K) reveals thermally activated delayed fluorescence, with sizable differences in the singlet–triplet energy gap compared to the reference compound [Cu(dmp)(POP)]+ (dmp = 2,9-dimethyl-1,10-phenanthroline) and within the pseudorotaxane series. The system with the largest ring ([Cu(m42)(POP)]+) has been tested as emissive material in OLEDs and affords bright green devices with higher luminance and greater stability compared to [Cu(dmp)(POP)]+, which lacks the macrocyclic ring. This highlights the importance of structural factors in the stability of electroluminescent devices based on Cu(I) materials.
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- 2018
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7. Dinuclear Cu(I) complexes prepared from 2-diphenylphosphino-6-methylpyridine
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Nicola Armaroli, Lydia Karmazin-Brelot, Filippo Monti, Jean-François Nierengarten, Juan-José Cid, Béatrice Delavaux-Nicot, Massimo Cocchi, Joanna M. Malicka, Gianluca Accorsi, Meera Mohankumar, John Mohanraj, Michel Holler, Iwona Nierengarten, Laboratoire de chimie moléculaire (LCM), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Consiglio Nazionale delle Ricerche [Roma] (CNR), Istituto per la Sintesi Organica e la Fotoreattività, Institut de Chimie de Strasbourg, Laboratory for Micro and Submicro Enabling Technologies of the Emilia-Romagna Region (MIST E-R), Università degli Studi di Ferrara (UniFE), 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), 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)
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Cu(I) complexes ,Bromoacetonitrile ,Luminescence ,Nitrile ,Photochemistry ,Chemistry ,Ligand ,Inorganic chemistry ,Solid-state ,Electrochemistry ,LEC devices ,Inorganic Chemistry ,Crystallography ,chemistry.chemical_compound ,Benzonitrile ,Solar energy ,Materials Chemistry ,[CHIM.COOR]Chemical Sciences/Coordination chemistry ,Physical and Theoretical Chemistry ,Triphenylphosphine oxide - Abstract
International audience; A series of reactions have been performed by mixing 2-diphenylphosphino-6-methyl-pyridine (dpPyMe) and [Cu(CH3CN)4]BF4 in different molar ratios. Starting from equimolar quantities of dpPyMe and Cu+, a dinuclear Cu(I) complex with two P,N binucleating bridging ligands has been obtained. This compound is stable in the solid state, however ligand exchange reactions leading to a mixture of species have been evidenced in solution. By increasing the amount of dpPyMe, the reaction of dpPyMe and [Cu(CH3CN)4]BF4 afforded the dinuclear Cu(I) complex [Cu2(μ-dpPyMe)3(CH3CN)](BF4)2 in which the three bridging dpPyMe ligands are in a head-to-head arrangement. This compound is remarkably stable in solution. It has been also shown that the axial CH3CN ligand of [Cu2(μ-dpPyMe)3(CH3CN)](BF4)2 can be suitably exchanged with other nitrile ligands [benzonitrile, 4-(dimethylamino)-benzonitrile, 4-nitrobenzonitrile and bromoacetonitrile] but also with triphenylphosphine oxide. The electrochemical and photophysical properties of the resulting complexes have been systematically investigated. The [Cu2(μ-dpPyMe)3(L)](BF4)2 derivatives are weak emitters in solution but remarkable emission quantum yields (6 to 46%) have been found in rigid matrices at room temperature. One complex was utilized as active material for preliminary tests in LEC devices.
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- 2014
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8. Current status and challenges of the modeling of organic photodiodes and solar cells
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T. Maindron, Alexandre Pereira, B. Racine, A. Revaux, Lionel Hirsch, Patrice Rannou, Jérôme Vaillant, Jean-Marie Verilhac, Y-F Chen, Benjamin Bouthinon, Meera Mohankumar, Raphael Clerc, Laboratoire Hubert Curien / Eris, Laboratoire Hubert Curien [Saint Etienne] (LHC), Université Jean Monnet [Saint-Étienne] (UJM)-Centre National de la Recherche Scientifique (CNRS)-Institut d'Optique Graduate School (IOGS)-Université Jean Monnet [Saint-Étienne] (UJM)-Centre National de la Recherche Scientifique (CNRS)-Institut d'Optique Graduate School (IOGS), Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et les nanomatériaux (LITEN), Institut National de L'Energie Solaire (INES), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Structures et propriétés d'architectures moléculaire (SPRAM - UMR 5819), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de l'intégration, du matériau au système (IMS), Université Sciences et Technologies - Bordeaux 1-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS), Laboratoire Hubert Curien (LHC), Institut d'Optique Graduate School (IOGS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Université Sciences et Technologies - Bordeaux 1 (UB)-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS)
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Materials science ,business.industry ,Doping ,Charge (physics) ,02 engineering and technology ,Numerical models ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,7. Clean energy ,0104 chemical sciences ,Solution processed ,Photodiode ,law.invention ,Organic semiconductor ,law ,Oxygen contamination ,Optoelectronics ,[SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,Current (fluid) ,0210 nano-technology ,business - Abstract
International audience; Progress in the modeling of charge transport in solution processed solar cells and photodiodes is reviewed. Through several examples involving modeling and original experiments, the role of intentional doping, structural defects, and oxygen contamination are discussed.
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- 2016
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9. Combining topological and steric constraints for the preparation of heteroleptic copper(I) complexes
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Jean-Pierre Sauvage, Nicola Armaroli, Frédéric Niess, Béatrice Delavaux-Nicot, Filippo Monti, Michel Holler, Meera Mohankumar, Jean-François Nierengarten, Laboratoire de chimie moléculaire (LCM), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Consiglio Nazionale delle Ricerche [Roma] (CNR), Istituto per la Sintesi Organica e la Fotoreattività, Institut de Science et d'ingénierie supramoléculaires (ISIS), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), 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), 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)
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Steric effects ,Chemistry ,Stereochemistry ,010405 organic chemistry ,Organic Chemistry ,chemistry.chemical_element ,bis-phosphine ligands ,General Chemistry ,self-assembly ,010402 general chemistry ,Copper ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Crystallography ,copper ,[CHIM.COOR]Chemical Sciences/Coordination chemistry ,phenanthroline ligands ,photophysical properties - Abstract
International audience; Heteroleptic copper(I) complexes have been prepared from a macrocyclic ligand incorporating a 2,9-diphenyl-1,10-phenanthroline subunit (M30) and two bis-phosphines, namely bis[(2-diphenylphosphino)phenyl] ether (POP) and 1,3-bis(diphenylphosphino)propane (dppp). In both cases, the diphenylphosphino moieties of the PP ligand are too bulky to pass through the 30-membered ring of M30 during the coordination process, hence the formation of C2v-symmetrical pseudo-rotaxanes is prevented. When POP is used, X-ray crystal structure analysis shows the formation of a highly distorted [Cu(M30)(POP)]+ complex in which the POP ligand is only partially threaded through the M30 unit. This compound is poorly stable as the CuI cation is not in a favorable coordination environment due to steric constraints. By contrast, in the case of dppp, the bis-phosphine ligand undergoes both steric and topological constraints and adopts a nonchelating coordination mode to generate [Cu2(M30)2(μ-dppp)](BF4)2. This compound exhibits metal-to-ligand charge transfer (MLCT) emission characterized by a very large Stokes’ shift (≈200 nm) that is not attributed to a dramatic structural distortion between the ground and the emitting states but to very weak MLCT absorption transitions at longer wavelengths. Accordingly, [Cu2(M30)2(μ-dppp)](BF4)2 shows unusually high luminescence quantum yields for CuI complexes, both in solution and in the solid state (0.5 and 7 %, respectively).
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- 2014
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10. Heteroleptic Copper(I) Complexes Prepared from Phenanthroline and Bis-Phosphine Ligands: Understanding their Photophysical Behavior
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Filippo Monti, John Mohanraj, Meera Mohankumar, Béatrice Delavaux-Nicot, Jean-François Nierengarten, and Nicola Armaroli
- Abstract
For most photochemists the archetypal luminescent metal complex is probably [Ru(bpy)3]2+, characterized by charge-transfer orange luminescence and a unique combination of chemical stability, redox and excited-state properties.[1] Early studies on Ru(II) coordination compounds were subsequently extended to other metals such as Os(II), Pd(II), Pt(II) and Rh(III) and, in relatively recent years, to cyclometalated Ir(III) complexes.[2] Widespread diffusion of new technologies based on these luminescent transition metal complexes might be hampered by the prohibitive costs of the metal elements, which are related to their scarcity in the Earth's crust. For this reason, in recent years, attention has grown towards less conventional luminescent metal compounds made from more abundant d10 metal ions, such as Cu(I), Ag(I), Au(I), Zn(II) and Cd(II). Key features of these complexes over compounds made from platinum group elements are (i) the lack of non-emissive low- lying MC levels that would quench the luminescent excited states by thermal equilibration or energy transfer, and (ii) a wider variety of coordination geometries. In this talk we report our most recent progress in the understanding of the photophysical properties of a library of heteroleptic [Cu(NN)(PP)]+ complexes prepared from phenanthroline derivatives (NN) and commercially available bis-phosphine ligands (PP). This work provides a deeper understanding of the stability of these complexes and a full rationalization of their photophysical properties, marking the way for future developments and, possibly, technological implementation of d10 metal complexes.[3,4] [1] A. Barbieri, G. Accorsi and N. Armaroli, Chem. Commun., 2008, 2185-2193. [2] R. D. Costa, E. Ortí, H. J. Bolink, F. Monti, G. Accorsi, and N. Armaroli, Angew. Chem., 2012, 8178-8211. [3] A. Kaeser, M. Mohankumar, J. Mohanraj, F. Monti, M. Holler, J.-J. Cid, O. Moudam, I. Nierengarten, L. Karmazin-Brelot, C. Duhayon , B. Delavaux-Nicot, N. Armaroli and J.-F. Nierengarten, Inorg. Chem., 2013, ASAP: 10.1021/ic4020042. [4] F. Monti, J. Mohanraj, A. Kaeser, M. Mohankumar, M. Holler, J.-J. Cid, O. Moudam, I. Nierengarten, L. Karmazin-Brelot, C. Duhayon , B. Delavaux-Nicot, J.-F. Nierengarten and N. Armaroli, MS in preparation.
- Published
- 2013
11. Dynamic topomerization of Cu(I)-complexed pseudorotaxanes
- Author
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Michel Schmitt, Meera Mohankumar, Michel Holler, Jean-Pierre Sauvage, and Jean-François Nierengarten
- Subjects
Models, Molecular ,Macrocyclic Compounds ,Rotaxanes ,Chemistry ,Component (thermodynamics) ,Metals and Alloys ,Molecular Conformation ,Temperature ,Stereoisomerism ,General Chemistry ,Crystal structure ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Folding (chemistry) ,Crystallography ,Motion ,Computational chemistry ,Materials Chemistry ,Ceramics and Composites ,Molecular motion ,Organometallic Compounds ,Copper - Abstract
Dynamic molecular motions resulting from the folding of a flexible macrocyclic component in a Cu(I)-complexed pseudorotaxane have been evidenced by variable temperature NMR experiments. The proposed conformational changes are also supported by the X-ray crystal structures of the compounds and computational studies.
- Published
- 2012
12. Preparation of copper(I) pseudo-rotaxanes from bis-phosphine ligands
- Author
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Jean-Pierre Sauvage, Meera Mohankumar, Michel Holler, and Jean-François Nierengarten
- Subjects
chemistry.chemical_compound ,Rotaxane ,chemistry ,Phenanthroline ,Organic Chemistry ,Polymer chemistry ,chemistry.chemical_element ,Organic chemistry ,General Chemistry ,Copper ,Catalysis ,Phosphine - Published
- 2012
13. Cover Picture: Combining Topological and Steric Constraints for the Preparation of Heteroleptic Copper(I) Complexes (Chem. Eur. J. 38/2014)
- Author
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Jean-François Nierengarten, Nicola Armaroli, Meera Mohankumar, Frédéric Niess, Jean-Pierre Sauvage, Béatrice Delavaux-Nicot, Michel Holler, and Filippo Monti
- Subjects
Steric effects ,Chemistry ,Computational chemistry ,Organic Chemistry ,chemistry.chemical_element ,Cover (algebra) ,General Chemistry ,Self-assembly ,Photochemistry ,Copper ,Catalysis - Published
- 2014
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14. Evaluation of Mg[B(HFIP) 4 ] 2 -Based Electrolyte Solutions for Rechargeable Mg Batteries
- Author
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Meera Mohankumar, David Zitoun, Ben Dlugatch, Ran Attias, Yuval Elias, Yosef Gofer, Balasubramoniam Murali Krishna, and Doron Aurbach
- Subjects
Materials science ,Passivation ,Magnesium ,Inorganic chemistry ,chemistry.chemical_element ,Electrolyte ,Electrochemistry ,Dimethoxyethane ,chemistry.chemical_compound ,chemistry ,General Materials Science ,Dissolution ,Deposition (chemistry) ,Faraday efficiency - Abstract
One of the greatest challenges toward rechargeable magnesium batteries is the development of noncorrosive electrolyte solutions with high anodic stability that can support reversible Mg deposition/dissolution. In the last few years, magnesium electrolyte solutions based on Cl-free fluorinated alkoxyborates were investigated for Mg batteries due to their high anodic stability and ionic conductivity and the possibility of reversible deposition/dissolution in ethereal solvents. Here, the electrochemical performance of Mg[B(hexafluoroisopropanol)4]2/dimethoxyethane (Mg[B(HFIP)4]2/DME) solutions was examined. These electrolyte solutions require a special "conditioning" pretreatment that removes undesirable active moieties. Such a process was developed and explored, and basic scientific issues related to the mechanism by which it affects Mg deposition/dissolution were addressed. The chemical changes that occur during the conditioning process were examined. Mg[B(HFIP)4]2/DME solutions were found to enable reversible Mg deposition, albeit with a relatively low Coulombic efficiency of 95% during the first cycles. Prolonged deposition/dissolution cycling tests demonstrate a stable behavior of magnesium electrodes. Overall, this system presents a reasonable electrolyte solution and can serve as a basis for future efforts to develop chlorine-free alternatives for secondary magnesium batteries. It is clear that such a conditioning process is mandatory, as it removes reactive contaminants that lead to unavoidable passivation and deactivation of Mg electrodes from the solution.
- Full Text
- View/download PDF
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