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Dendrimers and supramolecular chemistry continue to fascinate researchers due to the endless unrevealed potential of their combination. This study investigates the self-assembly process of a series of hydrophobic triazolylferrocenyl dendrimers in aqueous medium. Deep investigation through NMR spectroscopy, absorption UV-vis spectroscopy along with theoretical simulations demonstrates that the ferrocenyl moieties interact intramolecularly and intermolecularly driving the self-assembly process. Data obtained by DLS, NTA, SEM, TEM, and EF-TEM demonstrate that these dendrimers, in water, spontaneously self-assemble through a hierarchical process. The dendrimers first self-assemble into uniform nanovesicles, which in turn self-assemble into larger vesosomes. The resulting vesosomes emit green non-traditional intrinsic fluorescence, which is a property that emerged from the self-assembled architectures. The vesosomes are efficiently uptaken by cancer cells and induce significant cytotoxic activity against the cancer cell line MCF-7, up to the submicromolar concentration. Positive dendritic effects are identified in the fluorescence intensity and in the cytotoxic activity of the vesosomes, which follow the trend G0-9Fc < G1-27Fc < G2-81Fc. This work showcases the remarkable potential of combining the two dynamic fields of dendrimers and supramolecular chemistry, which resulted in green fluorescent vesosomes capable of performing the dual role of cell imaging and killing, with potential applications in nanotheranostics., (© 2024 Wiley‐VCH GmbH.)

The Cu-glutathione (GSH) redox system, essential in biology, is designed here as a supramacromolecular assembly in which the tetrahedral 18e Cu(I) center loses a thiol ligand upon adsorption onto ZIF-8, as shown by EXAFS and DFT calculation, to generate a very robust 16e planar trigonal single-atom Cu(I) catalyst. Synergy between Cu(I) and ZIF-8, revealed by catalytic experiments and DFT calculation, affords CO 2 conversion into high-value-added chemicals with a wide scope of substrates by reaction with terminal alkynes or propargyl amines in excellent yields under mild conditions and reuse at least 10 times without significant decrease in catalytic efficiency., (© 2024 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

This study explores the stabilization by niobic acid, of Pt, Ni, Pd, and Au nanoparticles (NPs) for the efficient microheterogeneous catalysis of NaBH 4 hydrolysis for hydrogen production. Niobic acid is the most widely studied Nb 2 O 5 polymorph, and it is employed here for the first time for this key reaction relevant to green energy. Structural insights from XRD, Raman, and FTIR spectroscopies, combined with hydrogen production data, reveal the role of niobic acid's Brønsted acidity in its catalytic activity. The supported NPs showed significantly higher efficiency than the non-supported counterparts regarding turnover frequency, average hydrogen production rate, and cost. Among the tested NPs, PtNPs and NiNPs demonstrate the most favorable results. The data imply mechanism changes during the reaction, and the kinetic isotope assay indicates a primary isotope effect. Reusability assays demonstrate consistent yields over five cycles for PtNPs, although catalytic efficiency decreases, likely due to the formation of reaction byproducts., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Electrocatalytic transformation of CO 2 to various syngas compositions is an exceedingly attractive approach to carbon-neutral recycling. Meanwhile, the achievement of selectivity, stability, and tunability of product ratios using single-component electrocatalysts is challenging. Herein, the theoretically-assisted design of the triple-component nanocomposite electrocatalyst Cu 10 Sn 3 -Cu-SnO x that addresses this challenge is presented. It is shown that Cu 10 Sn 3 is a valuable electrocatalyst for suitable CO 2 reduction to CO, SnO 2 for CO 2 reduction to formate at large overpotentials, and that the Cu-SnO 2 interface facilitates H 2 evolution. Accordingly, the interaction between the three functional components affords tunable CO/H 2 ratios, from 1:2 to 2:1, of the produced syngas by controlling the applied potentials and relative contents of functional components. The syngas generation is selective (Faradaic efficiency, FE = 100%) at relatively lower cathodic potentials, whereas formate is the only liquid product detected at relatively higher cathodic potentials. The theoretically guided design approach therefore provides a new opportunity to boost the selectivity and stability of CO 2 reduction to tunable syngas., (© 2023 Wiley‐VCH GmbH.)

Unsaturated furanic aldehydes are derived from lignocellulosic biomass resources and subsequently used to produce valuable chemicals. However, the highly efficient, selective hydrogenation of the biomass-derived unsaturated furan CO bond remains challenging. Here we report that graphene-like nitrogen doped porous carbon (GNPC) nanosheets are synthesized from carbon-rich, sustainable, and renewable biomass precursors (glucose, fructose and 5-hydroxymethylfurfural, HMF) with high surface areas, large pore volumes and narrow mesopores. GNPC derived from HMF is an excellent catalyst support for PtCo nanoparticles with ultrafine nanoparticles size and homogeneous distributions. This catalyst is highly efficient for hydrogenation of biomass-derived furan-based unsaturated aldehydes, with high yields, to the corresponding unsaturated alcohols under mild conditions. This design strategy should further allow the development of selective, simple, green heterogeneous catalysts for challenging chemical transformations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Approximately 20% of neonates with congenital cytomegalovirus (cCMV) develop long-term sequelae. The ability to accurately predict long-term outcomes as early as the neonatal period would help to provide for appropriate parental counseling and treatment indications. With this study, we aimed to identify neonatal predictive markers of cCMV long-term outcomes., Methods: As this study's subjects, we chose neonates diagnosed with cCMV in 13 hospitals throughout France recruited from 2013 to 2017 and evaluated for at least 2 years with thorough clinical, audiology, and imaging evaluations and psychomotor development tests., Results: A total of 253 neonates were included, and 3 were later excluded because of the identification of a genetic disorder. A total of 227 were followed up for 2 years: 187/227 (82%) and 34/227 (15%) were infected after a maternal primary or nonprimary infection, respectively, 91/227 (40%) were symptomatic at birth, and 44/227 (19%) had cCMV sequelae. Maternal primary infection in the first trimester was the strongest prognosis factor (odds ratio = 38.34 [95% confidence interval, 5.02-293], P < .001). A predictive model of no risk of sequelae at 2 years of age according to normal hearing loss at birth, normal cerebral ultrasound, and normal platelet count had 98% specificity, 69% sensitivity, and 0.89 area under the curve (95% confidence interval, 0.83-0.96)., Conclusions: In the studied population, children with normal hearing at birth, normal platelet count at birth, and a normal cranial ultrasound had no risk of neurologic sequelae and a low risk of delayed unilateral sensorineural hearing loss. The use of this model based on readily available neonatal markers should help clinicians establish a personalized care pathway for each cCMV neonate., (Copyright © 2024 by the American Academy of Pediatrics.)

Lignin, the most abundant natural material, is considered as a low-value commercial biomass waste from paper mills and wineries. In an effort to turn biomass waste into a highly valuable material, herein, a new-type of hollow carbon nanospheres (HCNs) is designed and synthesized by pyrolysis of biomass dealkali lignin, as an efficient nanocatalyst for the elimination of antibiotics in complex water matrices. Detailed characterization shows that HCNs possess a hollow nanosphere structure, with abundant graphitic C/N and surface N and O-containing functional groups favorable for peroxydisulfate (PDS) activation. Among them, HCN-500 provides the maximum degradation rate (95.0%) and mineralization efficiency (74.4%) surpassing those of most metal-based advanced oxidation processes (AOPs) in the elimination of oxytetracycline (OTC). Density functional theory (DFT) calculations and high-resolution mass spectroscopy (HR-MS) were employed to reveal the possible degradation pathway of OTC elimination. In addition, the HCN-500/PDS system is also successfully applied to real antibiotics removal in complex water matrices ( e.g. river water and tap water), with excellent catalytic performances., Competing Interests: The authors declare no competing financial interest., (This journal is © The Royal Society of Chemistry.)

Aim: Very preterm infants are exposed to an atypical environment that could alter their developmental trajectory. We aimed to examine neonatal imitation, a foundation of social cognition, in very preterm and full-term infants., Methods: In Strasbourg, France, between 2015 and 2018, we prospectively investigated the development of imitation skills. Very preterm (27 to 33 weeks of gestational age, n = 20) and full-term infants (n = 20) were enrolled using four gestures: tongue protrusion, mouth opening, sequential finger movements and hand movements. All testing were performed in infants at term-equivalent age. Two independent and blinded observers coded the behaviour of each infant on video recording. Facial expressions or hand movements, similar to the one presented, were quantified and classified according to their timing., Results: A total of 37 out of 40 infants imitated at least one gesture. The very preterm and term infants did not differ in the presence of imitation or its timing for the four gestures tested. The very preterm infants displayed more imitation abilities for sequential finger movement. Tongue protrusion and sequential finger movement were the particularly strong imitated gesture in both groups., Conclusion: These findings are the first to show similar neonatal imitation in term and very preterm infants. Our results may support early parent-infant social interactions., (©2021 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.)

Palladium is one of the most utilized metals in catalysis, particularly for hydrogenation and oxidation, cross C–C coupling, hydrogen formation, photocatalytic and electrocatalytic energy conversion reactions. Heterogeneous catalysis is undergoing a considerable move involving molecular aspects, which allows a better control and understanding of the structure–reactivity relationship toward optimization of the catalyst performances and selectivities. Inspired by organometallic catalysis, nanocatalytic materials that provide heterogeneization, nanocatalyst stabilization and optimized synergies include iron oxides, polymers, dendrimers, magnetic iron oxides, metal–organic and covalent-organic frameworks, carbons, atomically precise nanoclusters and other subnanoclusters such as single atoms, dual atoms and their combination and synergies with nanoparticles. In these nanocomposites, the number of catalytically utilized expansive Pd atoms is minimized. This mini-review addresses new trends of Pd nanocatalysis including these aspects with selected examples and examines perspectives. Progress of Pd nanocatalysis are reviewed including dramatic recent decrease of Pd sub-nanoparticle size utilizing modern organic or inorganic framework matrices. [ABSTRACT FROM AUTHOR]

Ferrocene has been the most used organometallic moiety introduced in organic and bioinorganic drugs to cure cancers and various other diseases. Following several pioneering studies, two real breakthroughs occurred in 1996 and 1997. In 1996, Jaouen et al. reported ferrocifens, ferrocene analogs of tamoxifen, the chemotherapeutic for hormone-dependent breast cancer. Several ferrocifens are now in preclinical evaluation. Independently, in 1997, ferroquine, an analog of the antimalarial drug chloroquine upon the introduction of a ferrocenyl substituent in the carbon chain, was reported by the Biot-Brocard group and found to be active against both chloroquine-sensitive and chloroquine-resistant strains of Plasmodium falciparum . Ferroquine, in combination with artefenomel, completed phase IIb clinical evaluation in 2019. More than 1000 studies have been published on ferrocenyl-containing pharmacophores against infectious diseases, including parasitic, bacterial, fungal, and viral infections, but the relationship between structure and biological activity has been scarcely demonstrated, unlike for ferrocifens and ferroquines. In a majority of ferrocene-containing drugs, however, the production of reactive oxygen species (ROS), in particular the OH. radical, produced by Fenton catalysis, plays a key role and is scrutinized in this mini-review, together with the supramolecular approach utilizing drug delivery nanosystems, such as micelles, metal-organic frameworks (MOFs), polymers, and dendrimers.

This review links various areas of inorganic chemistry around the themes developed by our research group during the last four decades. It is firstly based on the electronic structure of iron sandwich complexes, showing how the metal electron count dictates their reactivities, with various applications ( via C-H activation, C-C bond formation) as reducing and oxidizing agents, redox and electrocatalysts and precursors of dendrimers and catalyst templates through bursting reactions. Various electron-transfer processes and consequences are explored, including the influence of the redox state on the acidity of robust ligands and the possibility to iterate in situ C-H activation and C-C bond formation to build arene-cored dendrimers. Examples of how these dendrimers are functionalized are illustrated using the cross olefin metathesis reactions, with application to the synthesis of soft nanomaterials and biomaterials. Mixed and average valence complexes give rise to remarkable subsequent organometallic reactions, including the salt influence on these reactions. The stereo-electronic aspect of these mixed valencies is pointed out in star-shaped multi-ferrocenes with a frustration effect and other multi-organoiron systems, with the perspective of understanding electron-transfer processes among dendrimer redox sites involving electrostatic effects and application to redox sensing and polymer metallocene batteries. Dendritic redox sensing is summarized for biologically relevant anions such as ATP 2- with supramolecular exoreceptor interactions at the dendrimer periphery in parallel with the seminal work on metallocene-derived endoreceptors by Beer's group. This aspect includes the design of the first metallodendrimers that have applications in both redox sensing and micellar catalysis with nanoparticles. These properties provide the opportunity to summarize the biomedical (mostly anticancer) applications of ferrocenes, dendrimers and dendritic ferrocenes in biomedicine (in particular the contribution from our group, but not only). Finally, the use of dendrimers as templates for catalysis is illustrated with numerous reactions including C-C bond formation, click reactions and H 2 production reactions.

Hydrogen (H 2 ) 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 H 2 . 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 NaBH 4 , with performances surpassing those obtained using nanocatalysts in ZIF-8 or ZIF-67. The nanocatalysts Pd x Ag were optimized with ZIF-8@Pd 2 Ag 1 @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 light by the Ag plasmon resonance and the advantageous core-shell MOF structure. In order to examine the potential of extending this catalyst improvement principle to other catalytic reactions, 4-nitrophenol reduction, a benchmarking model of catalytic reaction, was tested, and the results also confirmed the superiority of the performance of ZIF-8@Pd 2 Ag 1 @ZIF-67 over Pd 2 Ag 1 @ZIF-8 and Pd 2 Ag 1 @ZIF-67, confirming the interest in the novel catalyst design.

Objectives: We aimed to evaluate (1) whether sedation analgesia (SA) used during therapeutic hypothermia (TH) was efficient to support the wellbeing of neonates with hypoxic-ischemic encephalopathy, (2) the SA level and its adjustment to clinical pain scores, and (3) the impact of inadequate SA on short-term neonatal outcomes evaluated at discharge., Methods: This was an observational retrospective study performed between 2011 and 2018 in two level III centers in Alsace, France. We analyzed the wellbeing of infants by using the COMFORT-Behavior (COMFORT-B) clinical score and SA level during TH, according to which we classified infants into four groups: those with excess SA, adequate SA, lack of SA, and variability of SA. We analyzed the variations in doses of SA and their justification. We also determined the impact of inadequate SA on neonatal outcomes at discharge by multivariate analyses with multinomial regression, with adequate SA as the reference., Results: A total of 110 patients were included, 89 from Strasbourg university hospital and 21 from Mulhouse hospital. The COMFORT-B score was assessed 95.5% of the time. Lack of SA was mainly found on the first day of TH (15/110, 14%). In all, 62 of 110 (57%) infants were in excess of SA over the entire duration of TH. Most dose variations were related to clinical pain scores. Inadequate SA was associated with negative short-term consequences. Infants with excess of SA had a longer duration of mechanical ventilation [mean ratio 1.46, 95% confidence interval (CI), 1.13-1.89, p  = 0.005] and higher incidence of abnormal neurological examination at discharge (odds ratio 2.61, 95% CI, 1.10-6.18, p  = 0.029) than infants with adequate SA., Discussion: Adequate SA was not easy to achieve during TH. Close and regular monitoring of SA level may help achieve adequate SA. Excess of SA can be harmful for newborns with hypoxic-ischemic encephalopathy who are undergoing TH., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Nakhleh-Philippe, Zores, Stern-Delfils, Escande, Astruc, Severac and Kuhn.)

Objective: To evaluate cytomegalovirus (CMV) viral load dynamics in blood and saliva during the first 2 years of life in symptomatic and asymptomatic infected infants and to identify whether these kinetics could have practical clinical implications., Study Design: The Cymepedia cohort prospectively included 256 congenitally infected neonates followed for 2 years. Whole blood and saliva were collected at inclusion and months 4 and 12, and saliva at months 18 and 24. Real-time CMV polymerase chain reaction (PCR) was performed, results expressed as log 10 IU/mL in blood and in copies per milliliter in saliva., Results: Viral load in saliva progressively decreased from 7.5 log 10 at birth to 3.3 log 10 at month 24. CMV PCR in saliva was positive in 100% and 96% of infants at 6 and 12 months, respectively. In the first month of life, neonatal saliva viral load of less than 5 log 10 was related to a late CMV transplacental passage. Detection in blood was positive in 92% of neonates (147/159) in the first month of life. No viral load threshold values in blood or saliva could be associated with a high risk of sequelae. Neonatal blood viral load of less than 3 log 10 IU/mL had a 100% negative predictive value for long-term sequelae., Conclusions: Viral loads in blood and saliva by CMV PCR testing in congenital infection fall over the first 24 months. In this study of infants affected mainly after primary maternal infection during pregnancy, all salivary samples were positive in the first 6 months of life and sequelae were not seen in infants with neonatal blood viral load of less than 3 log 10 IU/mL., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Biomass valorization is essential, particularly in emerging countries. Here, hydrochar from arabica coffee straw was functionalized with a triazole group (HD-TRz) for use as a support of palladium nanoparticles (PdNPs-HD-TRz) applied in the Ullmann coupling reaction for the first time. It provided remarkably excellent selectivities, conversions at a temperature as low as 45 °C and catalyst recyclability, surpassing previous literature performances. Hydrochar was obtained by one-pot reaction via hydrothermal synthesis, using NaOH solution as activating agent and functionalized with a 1,3-triazole group by CuAAC "click" reaction. The PdNPs were prepared via reduction of hydrochar-bound Pd(II) using NaBH 4 . Hydrochar functionalization was monitored by infrared spectroscopy, and X-ray diffraction (XRD) allowed to observe carbon and palladium planes in hydrochar and PdNPs HD-TRz structures. The PdNPs presented a spherical shape with 2.1 ± 0.1 nm size, homogeneously distributed in the carbon coverslips. The HD-TRz-supported PdNPs were used as a catalyst in the Ullmann reaction of iodobenzene, using ethanol as solvent with 100% of conversion and 91% selectivity at 45 °C. The material was reused, presenting 100% of conversion and selectivities of 92, 84 and 73% for the 1st, 2nd and 3rd cycle, respectively. The scope of the reaction was expanded to other molecules showing the potential of this and other triazole-hydrochar-supported nanocatalysts., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Atom-precise nanoclusters-metal-organic framework (APNC/MOF) composites, as bifunctional material with well-defined structures, have attracted considerable attention in recent years. Despite the progress made to date, there is an urgent need to develop a generic and scalable approach for all APNCs. Herein, the authors present the Exploiting Fracture Strategy (EFS) and successfully construct a super-stable bifunctional APNC/ZIF-8(300 °C) composite overcoming the limitations of previous strategies in selecting APNCs. The EFS utilizes the fracture of ZnN in ZIF-8 after annealing at 300 °C. This method is suitable for all kinds of S/P protected APNCs with different sizes, including uncharged clusters Au 1 Ag 39 , Ag 40 , negatively charged Au 12 Ag 32 , positively charged Ag 46 Au 24 , Au 4 Cu 4 and P-ligand-protected Pd 3 Cl. Importantly, the generated APNC/MOF show significantly improved performances, for example, the activities of Au 12 Ag 32 /ZIF-8(300°C), Au 4 Cu 4 /ZIF-8(300°C), and Au 1 Ag 39 /ZIF-8(300°C) in the corresponding reactions are higher than those of Au 12 Ag 32 , Au 4 Cu 4 , and Au 1 Ag 39 , respectively. In particular, Au 12 Ag 32 /ZIF-8(300 °C) shows higher activity than Au 12 Ag 32 @ZIF-8. Therefore, this work offers guidance for the design of bifunctional APNC/MOF composites with excellent optimization of properties and opens up new horizons for future related nanomaterial studies and nanocatalyst designs., (© 2022 Wiley-VCH GmbH.)

Although the chemistry of carbonyl-protected platinum nanoclusters is well established, their bonding mode remains poorly understood. In most of them, the average Pt oxidation state is zero or slightly negative, leading to the apparent average configuration 5d 10 6s ε ( ε = 0 or very small) and the apparent conclusion that metal-metal bonding cannot arise from the completely filled 5d shell nor from the empty (or almost empty) 6s orbitals. However, DFT calculations show in fact that in these species the actual average configuration is 5d 10- x 6s x , which provides to the whole cluster a significant total number of 6s electrons that ensures metal-metal bonding. This ("excited") average configuration is to be related to that of coinage metals in ligated group 11 nanoclusters ( n d 10 ( n + 1)s x ). Calculations show that metal-metal bonding in most of these platinum nanoclusters can be rationalized within the concepts of superatoms and supermolecules , in a similar way as for group 11 nanoclusters. The "excited" 5d 10- x 6s x configuration results from a level crossing between 5d combinations and 6s combinations, the former transferring their electrons to the latter. This level crossing, which does not exist in the bare Pt n clusters, is induced by the ligand shell, the role of which being thus not innocent with respect to metal-metal bonding.

Background: Patients in neonatal intensive care units (NICUs) are at high risk of adverse events. The effects of medical and paramedical education programmes to reduce these have not yet been assessed., Methods: In this multicentre, stepped-wedge, cluster-randomised controlled trial done in France, we randomly assigned 12 NICUs to three clusters of four units. Eligible neonates were inpatients in a participating unit for at least 2 days, with a postmenstrual age of 42 weeks or less on admission. Each cluster followed a 4-month multifaceted programme including education about root-cause analysis and care bundles. The primary outcome was the rate of adverse events per 1000 patient-days, measured with a retrospective trigger-tool based chart review masked to allocation of randomly selected files. Analyses used mixed-effects Poisson modelling that adjusted for time. This trial is registered with ClinicalTrials.gov, NCT02598609., Findings: Between Nov 23, 2015, and Nov 2, 2017, event rates were analysed for 3454 patients of these 12 NICUs for 65 830 patient-days. The event rate per 1000 patient-days reduced significantly from the control to the intervention period (33·9 vs 22·6; incidence rate ratio 0·67; 95% CI 0·50-0·88; p=0·0048)., Interpretation: A multiprofessional safety-promoting programme in NICUs reduced the rate of adverse events and severe and preventable adverse events in highly vulnerable patients. This programme could significantly improve care offered to critically ill neonates., Funding: Solidarity and Health Ministry, France., Competing Interests: Declaration of interests We declare no competing interests., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Electron transfer plays a major role in chemical reactions and processes, and this is particularly true of catalysis by nanomaterials. The advent of metal nanoparticle (NP) catalysts, recently including atomically precise nanoclusters (NCs) as parts of nanocatalyst devices has brought increased control of the relationship between NP and NC structures and their catalytic functions. Consequently, the molecular definition of these new nanocatalysts has allowed a better understanding and management of various kinds of electron transfer involved in the catalytic processes. This Minireview brings a chemist's view of several major aspects of electron-transfer functions concerning NPs and NCs in catalytic processes. Particular focus concerns the role of NPs and NCs as electron reservoirs and light-induced antenna in catalytic processes from H 2 generation to more complex reactions and sustainable energy production., (© 2021 Wiley-VCH GmbH.)

Bimetallic nanocluster with atomic precision has gained widespread attention due to its unique synergism. The coreless Au4Cu5 bimetallic nanoclusters were selected as models to explore the relationship between their microstructure and performance, and compare with the coreless monometallic nanoclusters, core–shell nanoclusters, and single atom catalyst (SAC). The experimental results show that the coreless bimetallic nanocluster catalyst Au4Cu5/activated carbon (AC) exhibits high activity and stability in the Ullmann C-O coupling reaction, much higher than coreless monometallic nanoclusters (Au11/AC and Cu11/AC), core–shell nanoclusters (Au25/AC, Cu25/AC, and Au1Cu24/AC), and single atom catalysts (Au SAC and Cu SAC). Moreover, the coreless Au4Cus/AC catalyst efficiently catalyzed the Ullmann C-O coupling of benzyl alcohol for the first time. This structure–activity relationship was successfully extended to other coreless bimetallic systems, such as Au4Cu4/AC nanocluster, and it is expected to provide new insights for the design of bimetallic catalysts with well-defined performance. [ABSTRACT FROM AUTHOR]

Hydrogen (H2) production is a key challenge for green carbon-free sustainable energy. Among the H2 evolution methods from H-rich materials, ammonia borane (AB) solvolysis stands as a privileged source under ambient and sub-ambient conditions given its stability, non-toxicity, and solubility in protic solvents, provided suitable and optimized nanocatalysts are used. In this paper dedicated to Prof. Avelino Corma, we comparatively review AB hydrolysis and alcoholysis (mostly methanolysis) in terms of nanocatalyst performances and discuss the advantages and inconveniences of these two AB solvolysis methods including AB regeneration. [ABSTRACT FROM AUTHOR]

Metal-metal contacts, though not yet widely realized, may provide exciting opportunities to serve as tunable and functional interfaces in single-molecule devices. One of the simplest components which might facilitate such binding interactions is the ferrocene group. Notably, direct bonds between the ferrocene iron center and metals such as Pd or Co have been demonstrated in molecular complexes comprising coordinating ligands attached to the cyclopentadienyl rings. Here, we demonstrate that ferrocene-based single-molecule devices with Fe-Au interfacial contact geometries form at room temperature in the absence of supporting coordinating ligands. Applying a photoredox reaction, we propose that ferrocene only functions effectively as a contact group when oxidized, binding to gold through a formal Fe 3+ center. This observation is further supported by a series of control measurements and density functional theory calculations. Our findings extend the scope of junction contact chemistries beyond those involving main group elements, lay the foundation for light switchable ferrocene-based single-molecule devices, and highlight new potential mechanistic function(s) of unsubstituted ferrocenium groups in synthetic processes., (© 2024. The Author(s).)

Gold nanoparticles (AuNPs) synthesized in the 1-3 nm range have a specific number of gold core atoms and outer protecting ligands. They have become one of the "hot topics" in recent decades because of their interesting physical and chemical properties. The characterization of their structures is usually achieved by crystal X-ray diffraction although the structures of some AuNPs remain unknown because they have not been successfully crystallized. An alternative method for studying the structure of AuNPs is electrospray ionization-ion mobility-tandem mass spectrometry (ESI-IM-MSMS). This research evaluated how effectively ESI-IM-MSMS using the commercially available Waters Synapt XS instrument yielded useful structural information from two AuNPs; Au 23 (S-tBu) 16 and Au 30 (S-tBu) 18 . The study used the maximum range of available collision energies along with ion mobility separation to measure the energy-dependence of the product ions and their drift times which is a measure of their spatial size. For Au 23 (S-tBu) 16 , the dissociation gave the masses of the outer protecting monomeric [RS-Au-SR] and trimeric [SR-Au-SR-Au-SR-Au-SR] staples where R = tBu, and complete dissociation of the outer layer Au and tBu groups to reveal the Au 15 S 8 core. For Au 30 (S-tBu) 18 , the dissociation products was primarily through the loss of the partial ligands S-tBu and tBu from the outer protecting layer and the loss of single Au 4 (S-tBu) 4 unit. These results showed the that ESI-IM-MSMS analysis of the smaller Au 23 (S-tBu) 16 gave information on all it major structural components whereas for Au 30 (S-tBu) 18 , the overall structural information was limited to the ligands of the outer layer., (© 2024 John Wiley & Sons Ltd.)

Metal nanoparticles have been widely used for catalysis because of its excellent catalytic activity and selectivity. Green and sustainable supports play a quite important role in the enhancement of the efficiency and recyclability of metal nanoparticles. Here, a cellulose/β-cyclodextrin hydrogel is applied to support tannic acid-encapsulated metal (such as Ag, Au, Pd and Cu) nanoparticles to generate nanocomposite hydrogels for catalysis. TEM analysis indicates that these metal nanoparticles have the average diameters of 6.5 nm for Au nanoparticles, 7.0 nm for Ag nanoparticles, 5.0 nm for Pd nanoparticles and 4.0 nm for Cu nanoparticles, respectively. The catalytic activities of the as-prepared metal nanocomposite hydrogels are estimated in a series of chemical reactions in the aqueous system. The recyclability, applicability and generality of these nanocomposite hydrogels are also well investigated. The nanocomposite hydrogels can be reused for at least 10 times in the 4-nitrophenol reduction, 8 times for Suzuki–Miyaura coupling reaction and 6 times for click reaction, respectively. Furthermore, good yields are obtained in the catalytic process. This study gives a green and sustainable strategy to support metal nanoparticles with good catalytic activity and recyclability. [ABSTRACT FROM AUTHOR]

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Metal-based catalysts play an essential role in organic chemistry and the chemical industry. This research designed and successfully synthesized a pillar-layered metal–organic framework (MOF) with the urea linkers, namely Basu-HDI, as a novel and efficient heterogeneous catalyst. Various techniques such as FT-IR, EDX, elemental mapping, SEM, XRD, BET, and TGA/DTA studied its structure and morphology. Then, we investigated the synthesis of new 1,8-naphthyridines utilizing Basu-HDI in mild conditions via a one‐pot, three‐component tandem Knoevenagel/Michael/ cyclization/anomeric-based oxidation reaction. Final products were achieved by anomeric-based oxidation without employing an oxidation agent. Remarkably, this tandem process gave a good range of new 1,8-naphthyridines with high yields in a short reaction time. The pure products were confirmed by FT-IR, 1H NMR, 13C NMR, and mass spectrometry techniques. Moreover, the introduced catalyst showed good efficiency and stability and can be reused four times without significantly reducing efficiency. [ABSTRACT FROM AUTHOR]

In this article, we report the modification and photocatalytic evaluation of commercial TiO2-P25 under visible light for methyl orange (MO) dye degradation under visible light. The activity of materials doped with N, Pd, Pt and Au on to the TiO2-P25 was evaluated, with optimal photocatalytic performance achieved using Au nanoparticles doped on an N-functionalized titania surface. X-ray diffraction (XRD), physical nitrogen adsorption/desorption isotherm curves, transmission electron microscopy (TEM), diffuse reflectance spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) were used to study the structural and textural properties of the samples. The chemical species present in the bulk and surface of the catalysts were identified using X-ray photoelectron spectroscopy (XPS) and microwave plasma-atomic emission spectroscopy. The results show that Au/N-TiO2 photocatalyst presents a remarkable enhanced activity for MO dye degradation, under visible light illumination, reaching 100% after 4 h. The enhanced photocatalytic activity using this composite is attributable to the well-dispersed and small size of Au nanoparticles, large surface area, reduction of band-gap energy and the interaction between nitrogen and Au which promoted a synergistic effect. This article is part of the discussion meeting issue 'Green carbon for the chemical industry of the future'. [ABSTRACT FROM AUTHOR]

A visible light-responsive magnetically separable photocatalyst Pd-g-C3N4-Vanillin@γ-Fe2O3-TiO2 is fabricated using vanillin as a natural junction under ultrasonic agitation. Structural, morphological, optical, thermal, and magnetic assessments of the as-prepared catalyst are carried out. The photocatalyst successfully drives the simultaneous benzimidazole formation, and olefin hydrogenation with high atom economy under blue LED light and mild conditions. The photocatalytic activity of Pd-g-C3N4-Vanillin@γ-Fe2O3-TiO2 is significantly affected by the γ-Fe2O3:TiO2 weight ratio. PL spectra revealed the effective separation of carriers in the fabricated catalyst promoting its photocatalytic activity. The action spectra using the apparent quantum efficiency (AQE) exhibited the maximum AQEs at 520 and 750 nm in which the highest performance for styrene hydrogenation is observed. The title magnetically separable heterogeneous photocatalyst provides high yields of products under perfectly safe visible light, produces low/zero waste, and avoids using an external high-pressure hydrogen gas source, harmful solvents, undesirable additives, and reducing agents rendering green conditions for chemical reactions. [ABSTRACT FROM AUTHOR]

This paper aims to present clear and evidence-based proposals for the integration of Early Parental Vocal Contact into the clinical practices of neonatal units. In the first part, we present a comprehensive rationale exploring the ontogenesis of voice perception in both term and preterm newborns that establishes a foundational understanding. This knowledge serves as a crucial starting point for developing evidence-based auditory and multisensory interventions aimed at fostering the developmental trajectory of preterm infants. Drawing insights from neuroscience and brain development, our proposals underscore the significance of tailoring auditory environments within neonatal settings. Special attention is given to the unique needs of preterm infants, factoring in their gestational age and maturation levels. In the second part clinical guidelines for implementation are provided and healthcare professionals are supported to assist parents in modulating their vocal interactions, aligning them with the infant's responses. Furthermore, we provide practical suggestions for engaging in discussions with parents about the content, duration, and frequency of vocal interventions. Finally, we delve into the potential roles of caregivers, parents, and health professionals within this enriched parental vocal interactional environment. Our perspective is firmly grounded in an infant and family-centered developmental care philosophy, aiming to enhance the overall well-being and the neurodevelopment of preterm infants in neonatal units. [ABSTRACT FROM AUTHOR]

Organometallics are chemical compounds that consist of carbon-metal linkages. They have emerged as a result of the combination of organic and inorganic chemistry and exhibit a stable metal-carbon bond in solution. These compounds possess properties that lie between those of ionic and covalent bonds, making them highly significant in various industries. The fact that organometallics are present in all living organisms further emphasises their importance. In this overview, we will explore general reactions, such as substitution and insertion reactions, as well as different techniques for creating organometallic complexes. Additionally, we will provide a brief synthesis review of various types of organometallic complexes, including carbonyls, hydrides, alkyls, carbenes, and carbines. Organometallic compounds find extensive applications in stoichiometric chemical processes in both research and industry. Moreover, they serve as catalysts to enhance these reactions, making them more than just theoretical compounds. For example, organotin compounds are widely used as fire retardants, polymers, medications, insecticides, and stabilizers for polyvinyl chloride. [ABSTRACT FROM AUTHOR]

As nanophysics constitutes the scientific core of nanotechnology, it has a decisive potential for advancing clean renewable energy applications. Starting with a brief foray into the realms of nanophysics' potential, this review manuscript is expected to contribute to understanding why and how this science's eruption is leading to nanotechnological innovations impacting the clean renewable energy economy. Many environmentally friendly energy sources are considered clean since they produce minimal pollution and greenhouse gas emissions; however, not all are renewable. This manuscript focuses on experimental achievements where nanophysics helps reduce the operating costs of clean renewable energy by improving efficiency indicators, thereby ensuring energy sustainability. Improving material properties at the nanoscale, increasing the active surface areas of reactants, achieving precise control of the physical properties of nano-objects, and using advanced nanoscale characterization techniques are the subject of this in-depth analysis. This will allow the reader to understand how nanomaterials can be engineered with specific applications in clean energy technologies. A special emphasis is placed on the role of such signs of progress in hydrogen production and clean storage methods, as green hydrogen technologies are unavoidable in the current panorama of energy sustainability. [ABSTRACT FROM AUTHOR]

Cysteine plays a crucial role in the development of an efficient copper-catalyst system, where its thiol group serves as a strong anchoring site for metal coordination. By immobilizing copper onto cysteine-modified, polydopamine-coated magnetite particles, this advanced catalytic platform exhibits exceptional stability and catalytic activity. Chemical modification of the polydopamine (PDA) surface with cysteine enhances copper salt immobilization, leading to the formation of the Fe3O4@PDA-Cys@Cu platform. This system was evaluated in palladium-free, copper-catalyzed Sonogashira coupling reactions, effectively catalyzing the coupling of terminal acetylenes with aryl halides. Additionally, the Fe3O4@PDA-Cys@Cu platform was employed in click reactions, confirming the enhanced catalytic efficiency due to increased copper content. The reusability of the platform was further investigated, demonstrating improved performance, especially in recyclability tests in click reaction, making it a promising candidate for sustainable heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) and functionalized graphene oxide (fGO), owing to their vast range of advantages, including simple preparation, low cost, recyclability, reusability, remarkable optical, electronic, and mechanical properties and the fact that they are environmentally friendly, have attracted considerable attention in heterogeneous catalytic systems during the past decades. The various catalytic activities displayed by GO and fGO result from the synergistic effects caused by their large surface area and the vast number of functional groups or nanoparticles bound to their plane. In this review, we investigate main mechanistic roles played by GO and fGO in chemical reactions. Contributing to oxidation, hydration, reduction and carbon–carbon coupling reactions, acting as acidic catalysts, nucleophiles, electrophiles, π-electron-rich adsorbing supports, photoacatalysts, and phase transfer catalysts, GO and fGO are employed in plenty of organic transformations. As the main goal of the review, we present a comprehensive overview on GO- and fGO-based reactions classified by the mechanistic roles of these carbocatalyst systems to provide insight into the design and development of novel carbon-based catalysts displaying improved performance. GRAPHICAL ABSTARCT: [ABSTRACT FROM AUTHOR]

Nanotechnology has currently grown rapidly in various areas. Limiting particle size to the nanometer-scale changes the physical, optical, chemical, and biological properties of materials, leading to versatility in different industrial applications including food, agriculture, pharmaceuticals, and biomedicine. Besides, the adjustable features of nanomaterials (NMs) enable us to manipulate their characteristics, obtaining smart or functional NMs. The surface modification of NMs is carried out in different physical forms. Hence, physical methods such as absorption or coating in front of chemical methods like surface oxidation followed by the change of electronic state of atoms have been developed for these modifications. Recently, various types of functional NMs, consisting of carbon nanotubes (CNTs), polymer structures, and nanocrystals, have been considered in the industry. Regarding the food and agriculture industry, nanofilms and nanoclays play a crucial role as barrier materials at various stages of the food chain. In the pharmaceutical and medical section, NMs have been utilized in drug and gene delivery systems to alleviate the side effects of therapeutic agents with more impact on target tissues like cancer therapy. Furthermore, synthetic biomass, production of new proteins, nanowire sensors, and provision of nanoscale levers to detect cancer cells are other advances based on NMs. In this review, our goal is to provide an overview of recent advancements in application of NMs in various areas of biology, including food and agriculture, pharmaceutical, and biomedical industries. [ABSTRACT FROM AUTHOR]

The reliance on fossil fuels intensifies CO2 emissions, worsening political and environmental challenges. CO2 capture and conversion present a promising solution, influenced by industrialization and urbanization. In recent times, catalytic conversion of CO2 into fuels and chemical precursors, particularly methane, are gaining traction for establishing a sustainable, carbon-neutral economy due to methane’s advantages in renewable energy applications. Though homogeneous and heterogeneous catalysts are available for the conversion of CO2 to methane, the efficiency is found to be higher in heterogeneous catalysts. Therefore, this review focuses only on the heterogeneous catalysts. In this context, the efficient heterogeneous catalysts with optimum utility are yet to be obtained. Therefore, the quest for suitable catalyst for the catalytic conversion of CO2 to CH4 is still continuing and designing efficient catalysts requires assessing their synthetic feasibility, often achieved through computational methods like density functional theory simulations, providing insights into reaction mechanisms, rate-limiting steps, catalytic cycle, activation of C=O bonds and enhancing understanding while lowering costs. In this context, this review examines the conversion of CO2 to CH4 using seven distinct types of catalysts, including single and double atom catalysts, metal organic frameworks, metalloporphyrins, graphdiyne and graphitic carbon nitrite and alloys with some case studies. The main focus of this review is to offer a detailed and extensive examination of diverse catalyst design approaches and their utilization in CH4 production, with a specific emphasis on computational aspects. It explores the array of design methodologies used to identify reaction pathways and investigates the critical role of computational tools in their refinement and enhancement. We believe this review will help budding researchers to explore the possibilities of designing catalysts for the CO2 to CH4 conversion from computational framework. [ABSTRACT FROM AUTHOR]

Laser desorption/ionization mass spectrometry (LDI-MS) techniques have emerged as powerful tools for analyzing compounds of natural and synthetic origins. However, conventional methods like matrix-assisted laser desorption/ionization (MALDI) often suffer from background signals and limited detection capabilities, particularly for low molecular weight compounds. Surface-assisted laser desorption/ionization (SALDI) methodologies, utilizing nanomaterials, have shown promise in overcoming these limitations. Gold nanoparticles (AuNPs) are among the most widely utilized nanomaterials in SALDI-MS applications. AuNPs offer several advantages over traditional MALDI matrices, such as reduced interference, internal calibration potential, and enhanced stability. They have been successfully employed for analyzing a diverse range of analytes, from low molecular weight (LMW) compounds to peptides, proteins, and biological entities. This paper provides a comprehensive overview of various synthesis methods, morphological properties, and comparisons with conventional MALDI matrices. Furthermore, it explores the application of AuNPs for analyzing LMW compounds and imaging various surfaces using LDI-MS techniques. [ABSTRACT FROM AUTHOR]

The major impediment to the additional industrialization of water splitting is the high cost of the co-catalyst made of noble metals and the sacrificial reagent. A binary photocatalytic system, consisting of B-doped g-C3N4 nanosheets (Cu20@BCN-X) and atomically accurate copper clusters, is designed in this study. The copper clusters serve as co-catalysts for H2 evolution and exhibit Pt-like activity, whereas the nanosheets serve as carriers and semiconductor components for O2 evolution. Such binary system, created using simple techniques, demonstrates hydrogen bonding interactions that promote synergistic effects and efficient binding and charge transfer across the interface between the two components. Band position manipulation of carbon nitride nanosheets demonstrates a Z-scheme charge transfer mechanism between the nanosheets and copper clusters. This photocatalytic system can accomplish the photocatalytic overall water splitting process (259.9 µmol g−1 h−1 of H2 and 129.4 µmol g−1 h−1 of O2) without using sacrificial agents or noble metal co-catalysts. This work lays the foundation for the design of overall water splitting catalysts by precisely manipulating the energy levels, and it also paves the way for commercialized photocatalytic catalysts that do not require noble metals or sacrificial chemicals. [ABSTRACT FROM AUTHOR]

The impregnation method in the preparation of metal cluster catalysts typically inadvertently introduces single atoms (SAs) into the substrate. However, the question of whether the introduction of SAs will further improve the catalytic activity of cluster systems for specific reactions such as the hydrogen oxidation reaction (HOR) remains unraveled. Herein, we demonstrate Ru clusters anchored on WN nanowires (RuC/WN) show a higher alkaline HOR catalytic activity in comparison with Ru SAs and nanoclusters (NCs)-coupled catalyst anchored on WN nanowires system (RuC,S/WN). Notably, the RuC/WN exhibits superb intrinsic catalytic activity with a mass-normalized exchange current density of 890 mA mg−1PGM, which is among the top level of well developed Ru-based HOR catalysts. Both theoretical simulation and experimental investigation suggest that RuC/WN owns an optimized H* and OH* reaction intermediates for the alkaline HOR, therefore resulting in the excellent intrinsic HOR catalytic performance. [ABSTRACT FROM AUTHOR]

Natural photosynthesis utilizes solar energy to convert water and atmospheric CO2 into carbohydrates through all-weather light/dark reactions based on molecule-based enzymes and coenzymes, inspiring extensive development of artificial photosynthesis. However, development of efficient artificial photosynthetic systems free of noble metals, as well as rational integration of functional units into a single system at the molecular level, remain challenging. Here we report an artificial system, the assembly system of Cu6 cluster and cobalt terpyridine complex, that mimics natural photosynthesis through precise integration of nanozyme complexes and ubiquinone (coenzyme Q) on Cu6 clusters. This biomimetic system efficiently reduces CO2 to CO in light reaction, achieving a production rate of 740.7 μmol·g−1·h−1 with high durability for at least 188 hours. Notably, our system realizes the decoupling of light and dark reactions, utilizing the phenol-evolutive coenzyme Q acting as an electron reservoir. By regulating the stabilizer of coenzyme Q, the dark reaction time can be extended up to 8.5 hours, which fully meets the natural day/night cycle requirements. Our findings advance the molecular design of artificial systems that replicate the comprehensive functions of natural photosynthesis. Natural photosynthesis converts H2O and CO2 into carbohydrates through all-weather reactions based on enzymes and coenzymes. Here, the authors report an artificial photosynthesis system under intermittent light irradiation by integrating nanozyme complexes and ubiquinone on a copper nanocluster. [ABSTRACT FROM AUTHOR]

A palladium capsule, made of three cavitands, namely P,P-dichlorido{5,17-bis[5-(diphenylphosphanyl)-4(24),6(10),12(16),18(22)-tetramethylenedioxy-2,8,14,20-tetrapentylresorcin[4]arenyl-17-oxymthyl]-4(24),6(10),12(16),18(22)-tetramethylenedioxy-2,8,14,20-tetrapentylresorcin[4]arene}palladium(II) (1), was synthetized by coordination of the corresponding diphosphinated ligand and the palladium precursor [PdCl2(PhCN)2] in 27% yield. The obtained P,P-chelate complex was fully characterized by elemental analysis, NMR and mass spectrometry. Molecular dynamics simulations carried out on the metallo-capsule showed the structure made by the three cavitands was slightly distorted over the 1 μs of the simulation. The evaluation of the palladium capsule 1 in the reaction between arylacetylenes and Et3SiH in undried conditions unequivocally demonstrates a drastic change in chemoselectivity, with the formation of the partially hydrogenation product rather than the hydrosilylation products observed with complexes whose active center is more accessible, for instance [PdCl2(PPh3)2]. [ABSTRACT FROM AUTHOR]

Notch development at the base of sea cliffs is an important control on cliff recession rates, but a detailed mechanistic understanding of notch formation by swash abrasion is lacking. We conducted physical experiments, using homogeneous erodible rock simulants, to study notch‐forming mechanisms under periodic sediment‐laden bore impacts. Our findings reveal shifts in the temporal dynamics of notch development. Initially, swash uprush and vortex formation contribute to a positive feedback loop that creates a shallow and wide notch. Subsequently, upward erosion ceases, and notch backwear and downwear are dominated by the vortex. Eventually, sediment deposition armors the notch floor; this negative feedback loop reduces erosion. The sediment size determines the amount of erosion, with a range of grain sizes generating maximum erosion. This indicates a dependence on the momentum of the sediment particles entrained within the bore. This research reveals fundamental notch formation mechanisms driven by swash abrasion. Plain Language Summary: When waves attack a rock cliff, they gradually undercut the cliff and remove materials, forming a wave‐cut notch. Studying how notches form and develop in natural settings takes a very long time, so we created a weaker cliff in the laboratory using easily eroded foam. The cliff was exposed to repeated impacts from bores carrying sediment, representing the impact of broken waves. Notch formation is observed over a few hundred hours. Initially, the notch is wide and shallow. As it grows, abrasive sediment cannot be propelled into the roof, stopping the upward expansion of the notch, and sediment piles up at the bottom, blocking further downward erosion. The notch continues to deepen, but at a decreasing rate. The size of the beach sand or gravel has an important influence on the erosion rate. If the sediments are too large or too small, little erosion occurs, whereas sediments of a certain size can cause rapid erosion. This is because waves need to be able to entrain sediment and hurl it with sufficient force against the cliff to cause erosion. Key Points: Controlled laboratory experiments with repeated swash impacts reveal positive and negative feedback mechanisms in abrasion notch formationNotch geometry varies over time and is determined by swash impact location, vortex formation and sediment depositionGrain size modulates beach shape and sediment‐laden bore momentum, collectively influencing notch development [ABSTRACT FROM AUTHOR]

In this work, the nonlinear optical (NLO) properties of CuO nanoparticles (CuO NPs) were studied experimentally using the pulsed laser ablation (PLA) technique. A nanosecond Nd: YAG laser was employed as the ablation excitation source to create CuO NPs in distilled water. Various CuO NPs samples were prepared at ablation periods of 20, 30, and 40 min. Utilizing HR-TEM, the structure of the synthesized CuO NPs samples was verified. In addition, a UV–VIS spectrophotometer was used to investigate the linear features of the samples. The Z-scan technique was utilized to explore the NLO properties of CuO NPs samples, including the nonlinear absorption coefficient (β) and nonlinear refractive index ( n 2 ). An experimental study on the NLO features was conducted at a variety of excitation wavelengths (750–850 nm), average excitation powers (0.8–1.2 W), and CuO NPs sample concentrations and sizes. The reverse saturable absorption (RSA) behavior of all CuO NPs samples differed with the excitation wavelength and average excitation power. In addition, the CuO NPs samples demonstrated excellent optical limiters at various excitation wavelengths, with limitations dependent on the size and concentration of CuO NPs. [ABSTRACT FROM AUTHOR]

Cobaltocenium-containing (co)polysiloxanes (Cc-PDMSs) with terminal and side groups were synthesized by the reaction of catalyst-free hydroamination between ethynylcobaltocenium hexafluorophosphate and polysiloxanes comprising amino moieties as terminal and side groups. The conversion of NH2 groups in the polymers reaches 85%. The obtained (co)polysiloxanes "gelate" due to an increase in their molecular weight by approx. 30 times, when stored at room temperature over one week. "Gelated" Cc-PDMSs remain soluble in most polar solvents. The structure of Cc-PDMSs and the mechanism of "gelation" were established by 1H, 13C{1H}, 29Si{1H}, 19F{1H}, 31P{1H} nuclear magnetic resonance, infrared, ultraviolet–visible, and X-ray photoelectron spectroscopies. As determined by cyclic voltammetry, Cc-PDMSs possess redox properties (CoII/CoIII transitions at E1/2 = −1.8 and −1.3 V before and after "gelation", respectively). This synthetic approach allows to increase the molecular weights of the synthesized polysiloxanes functionalized with cobaltocenium groups easily, leading to their higher film-forming ability, which is desirable for some electronic applications. Cc-PDMSs can be utilized as redox-active polymer films in modified electrodes, electrochromic devices, redox-active coatings, and components for batteries. [ABSTRACT FROM AUTHOR]