205 results match your criteria: "UMR 6200 CNRS-Université d'Angers[Affiliation]"

Thiophenyl Anilato-Based NIR-Emitting Lanthanide (Ln = Er, Yb) Dinuclear Complexes.

Molecules

December 2024

Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Complesso Universitario di Monserrato, S.P. 8 Km 0.700, I-09042 Monserrato, Italy.

By combining Er and Yb ions with 3,6-dithiophene-anilate (ThAn) and scorpionate hydrotris(pyrazol-1-yl)borate (HBpz) ligands new luminescent dinuclear complexes are obtained. The two materials formulated as [((HB(pz))Yb)(μ-thAn)]·4DCM·1.3HO and [((HB(pz))Er)(μ-thAn)]·4DCM·1.

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Endothelial cells (ECs) are highly plastic, capable of differentiating into various cell types. Endothelial-to-mesenchymal transition (EndMT) is crucial during embryonic development and contributes substantially to vascular dysfunction in many cardiovascular diseases (CVDs). While targeting EndMT holds therapeutic promise, understanding its mechanisms and modulating its pathways remain challenging.

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Elaboration and rheological characterization of nanocomposite hydrogels containing C fullerene nanoplatelets.

Soft Matter

January 2024

Institut des Molécules et Matériaux du Mans, UMR CNRS 6283, Le Mans Université, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France.

Nanocomposite hydrogels were elaborated that consisted of a physical network formed by an amphiphilic polymer in which C fullerene nanoplatelets were embedded. Characterization showed that the nanoplatelets within the polymer network were aggregated. The presence of these nanoplatelets led to an increase of the shear modulus of the hydrogels, that cannot be explained by a filler effect alone.

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Terbium and Europium Chlorocyananilate-Based 2D Coordination Polymers.

Molecules

September 2023

Department of Chemical and Geological Sciences, University of Cagliari, Highway 554, Crossroads for Sestu, I-09042 Monserrato, Italy.

Two-dimensional layered coordination polymers based on the hetero-substituted 3-chloro-6-cyano-2,5-dihydroxybenzoquinone ligands, hereafter ClCNAn anilate, and Ln ions (Tb and Eu) are reported. Compounds and , formulated as Ln(ClCNAn)(DMSO) (Ln = Tb, ; Eu, ), and their related intermediates and , formulated as Ln(ClCNAn)(HO)·yHO (x + y likely = 12, Ln = Tb, ; and Eu, ), were prepared by a conventional one-pot reaction (the latter) and recrystallized from DMSO solvent (the former). Polyhydrated intermediates and show very similar XRPD patterns, while, despite their common stoichiometry, and are not isostructural.

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A series of monolayered lead halide hybrid perovskites (HOC(CH)NH)PbX, named (C)PbX ( = 4-6, X = Cl, Br), exhibiting a low congruent melting temperature () ( = 130 °C for (C4)PbBr), high stability in the molten state, and whitish type emission, are reported. From the synthesis in the molten state, rare solid solutions of mixed organic cations (CC')PbX (, ' = 4-6; X = Cl, Br; 0 ≤ ≤1) as well as solid solutions of mixed halides (C)Pb(XX') ( = 4-6; X, X' = Cl, Br; 0 ≤ ≤1) have been prepared and characterized (thermal behavior, powder X-ray diffraction (PXRD), photoluminescence properties). The impact of substitutions is significant on the thermal properties, lowering the down to 100 °C for (C4)Pb(BrCl).

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Solvent-Free Preparation and Moderate Congruent Melting Temperature of Layered Lead Iodide Perovskites for Thin-Film Formation.

Angew Chem Int Ed Engl

August 2022

Istituto di Scienze e Tecnologie Chimiche "G. Natta" (SCITEC), CNR, Via Corti 12, 20133, Milano, Italy.

Lead halide 2D hybrid perovskites (HP) have emerged as promising materials for photovoltaic and lighting applications. Solvent-free preparations offer greener route, but require congruent melting of halide perovskite for thin films, which has been demonstrated only for monolayered HP (n=1 of the (A) (MA) Pb I series) at the quite high temperature T (T ) of 171 °C. Here, we report on the solvent-free preparation (n=2, 4), thermal behaviour and melt-processed thin films of a series of HP (GABA) (MA) Pb I (n=1, 2, 4; GABA : 4-ammoniumbutyric acid cation).

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On the remarkable nonlinear optical properties of natural tomato lycopene.

Sci Rep

May 2022

UNESCO-UNISA-iTLABS/NRF Africa Chair in Nano-Sciences & Nanotechnology, CGS, University of South Africa, Muckleneuk ridge, Pretoria, 0001, South Africa.

In line with the renewed interest in developing novel Non Linear Optical (NLO) materials, natural Lycopene's NLO Properties are reported for the first time within the scientific literature. Correlated to its 1-D conjugated π-electrons linear conformation, it is shown that natural Lycopene exhibits a significantly elevated 3rd order nonlinearity χ as high as 2.65 10 esu, the largest value of any investigated natural phyto-compound so far, including β-carotene.

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Here we present a newly synthesized bifunctional organic chromophore with appealing spectroscopic and nonlinear optical features. The positions of absorption and emission maxima of the dye vary with increasing solvent polarity and exhibit positive solvatochromism. The determined change in the dipole moment upon excitation based on the Bilot and Kawski theory is 5.

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Multi-State Second-Order Nonlinear Optical Switches Incorporating One to Three Benzazolo-Oxazolidine Units: A Quantum Chemistry Investigation.

Molecules

April 2022

Theoretical Chemistry Laboratory, Unit of Theoretical and Structural Physical Chemistry, Namur Institute of Structured Matter, University of Namur, B-5000 Namur, Belgium.

This contribution employs quantum chemistry methods to describe the variations of the second nonlinear optical responses of molecular switches based on benzazolo-oxazolidine (BOX) units, connected by -linkers, along their successive opening/closing. Under the fully closed forms, all of them display negligible first hyperpolarizability () values. When one BOX is opened, which is sketched as →, a push-pull -conjugated segment is formed, having the potential to enhance and to set the depolarization ratio (DR) to its one-dimensional-like value (DR = 5).

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Theoretical and experimental investigations of the linear and nonlinear optical properties of composite materials based on the (Z)-4-(1-cyano-2-(5-methylfuran-2-yl)vinyl)benzonitrile molecule named as A, the (Z)-4-(2-(benzofuran-2-yl)-1-cyanovinyl)benzonitrile named as B and the (Z)-4-(2-(4-(9H-carbazol-9-yl)phenyl)-1-cyanovinyl)benzonitrile molecule named as C embedded into poly(1-vinylcarbazole) (PVK) polymer matrix were performed. The electronic and optical properties of A, B, and C molecules in a vacuum and PVK were calculated. The guest-host polymer structures for A, B, and C molecules in PVK were modeled using molecular dynamics simulations.

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An optical control of many working optoelectronic systems (real-time sensors, optical modulators, light amplifiers, or phase retarders) giving efficient optical gain or remote signal modulation is currently included as scientifically and industrially interesting. In here, an oxazolone derivative as the multifunctional organic system is given in this contribution. The molecule possesses a stilbene group and an oxazolone heteroatomic ring, which implies effective refractive index manipulation and multimode lasing action, respectively.

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From Zero- to One-Dimensional, Opportunities and Caveats of Hybrid Iodobismuthates for Optoelectronic Applications.

Inorg Chem

November 2021

Univ Rennes, ENSCR, INSA Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), UMR 6226, Rennes F-35000, France.

The association of the electron acceptor 4,4'-amino-bipyridinium (AmV) dication and BiI in an acidic solution affords three organic-inorganic hybrid materials, (AmV)(BiI) (), (AmV)(BiI) (), and (AmV)BiI (), whose structures are based on isolated BiI and BiI anion clusters in and , respectively, and on a one-dimensional (1D) chain of -connected corner-sharing octahedra in . In contrast with known methylviologen-based hybrids, these compounds are more soluble in polar solvents, allowing thin film formation by spin-coating. (AmV)BiI exhibits a broad absorption band in the visible region leading to an optical bandgap of 1.

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Marennine has long been known as the unique peculiar pigment responsible for the natural greening of oysters. It is specifically produced by the marine diatom and it is a natural blue molecule indeed promising for food industry because of the rarity of such non-toxic, blue-colored pigments. In the search for its still not defined molecular structure, investigation of the color changes with the redox state has been carried out combining different approaches.

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Capacitive Impedance for Following In-Situ Grafting Kinetics of Diazonium Salts.

Chemphyschem

June 2021

MOLTECH-Anjou, Université D'Angers, UMR CNRS 6200, 2 Boulevard Lavoisier, 49045, Angers, France.

A new method to follow in-situ grafting kinetics of diazonium compounds based on imposing small amplitude high frequency AC oscillations at grafting potential, is outlined. This enables the time-resolved measurements of capacitive impedance concomitantly with the growth of the organic layer at the working electrode. The impedance values were quantitatively correlated with the ex-situ (from voltammograms) and in-situ (from quartz crystal microbalance) measured surface coverages, providing a validation of the new methodology.

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Recent interest in potassium-doped -terphenyl has been fueled by reports of superconductivity at values surprisingly high for organic compounds. Despite these interesting properties, studies of the structure-function relationships within these materials have been scarce. Here, we isolate a phase-pure crystal of potassium-doped -terphenyl: [K()][-terphenyl].

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The Key Role of the Interface in the Highly Sensitive Mechanochromic Luminescence Properties of Hybrid Perovskites.

Angew Chem Int Ed Engl

January 2021

Istituto di Scienze e Tecnologie Chimiche "G. Natta" (SCITEC), CNR, Via Corti 12, 20133, Milano, Italy.

Hybrid perovskite (HP) materials are of interest in photovoltaics and lighting applications. Here we report that hybrid perovskite composites, as crystallized powders, can behave as intelligent materials showing highly sensitive and reversible mechanochromic luminescence (MCL). Composites consisting of monolayered 2D HP and 3D HP components exhibit reversible tunable color emission upon mechanical strain.

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The new heterometallic complex, aqua-1κ-bis-(μ-2-imino-methyl-6-meth-oxy-phenolato-1κ , :2κ ,)bis-(thio-cyanato-1κ)calcium(II)copper(II), [CaCu(CHNO)(NCS)(HO)], has been synthesized using a one-pot reaction of copper powder, calcium oxide, -vanillin and ammonium thio-cyanate in methanol under ambient conditions. The Schiff base ligand (CHNO) is generated from the condensation of -vanillin and ammonia, which is released from the initial NHSCN. The title compound consists of a discrete binuclear mol-ecule with a {Cu(μ-O)Ca} core, in which the Cu⋯Ca distance is 3.

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Superatomic crystals are composed of discrete modular clusters that emulate the role of atoms in traditional atomic solids. Owing to their unique hierarchical structures, these materials are promising candidates to host exotic phenomena, such as doping-induced superconductivity and magnetism. Low-dimensional superatomic crystals in particular hold great potential as electronic components in nanocircuits, but the impact of doping in such compounds remains unexplored.

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Nanoparticles (NPs) based on biocompatible and biodegradable polymers such as poly(lactic-co-glycolic acid) (PLGA) and polycaprolactone (PCL) represent effective systems for systemic drug delivery. Upon injection into the blood circuit, the NP surface is rapidly modified due to adsorption of proteins that form a 'protein corona' (PC). The PC plays an important role in cellular targeting, uptake and NP bio-distribution.

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The synthesis of heterocyclic spirobifluorene (SBF) analogs generally requires long and complicated synthetic pathways. Despite this synthetic effort, such structural modification allows the (opto)electronic properties of this remarkable three-dimensional node to be tuned especially for molecular electronic applications. For this reason, the development of a simple, robust, and efficient synthetic methodology to introduce various heterocycles in place of classical phenyl rings in the spirofluorene motif is highly and timely desirable.

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A series of linear benzofuran derivatives consisting of either a vinylene or a cyanovinylene were prepared in order to investigate their emission properties. The X-ray crystallography of structurally similar derivatives was also evaluated. The crystalline structures of the vinylene derivatives showed only lateral contacts that involved the benzofurans and no π-stacking.

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The controlled electrochemical deposition of a series of four diazonium salts (4-bromobenzene, 4-iodobenzene, 4-methoxybenzene, and 4-diethylaminobenzene diazonium) on carbon surfaces has been achieved by exploiting the use of three redox mediators: 2,2-diphenyl-1-picrylhydrazyl, chloranil, and dichlone. The efficiency of the method rests on a fast redox cross-reaction in the diffusion layer between the diazonium compound and the reduced form of the selected inhibitor, characterized by an outer-sphere electron transfer. The effect of the inhibitor addition in the deposition solution was characterized using electrochemical techniques, X-ray photoelectron spectroscopy, and atomic force microscopy.

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Enhanced Stability and Band Gap Tuning of α-[HC(NH)]PbI Hybrid Perovskite by Large Cation Integration.

ACS Appl Mater Interfaces

June 2019

Univ Rennes, ENSCR, INSA Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226 , F-35000 Rennes , France.

We report room-temperature synthesis of lead- and iodide-deficient α-[HC(NH)]PbI perovskites (abbreviated d-α-FAPI, FA = formamidinium), with the general formula (A',FA)[PbI] (with A' = hydroxyethylammonium (HEA) or thioethylammonium (TEA) cations, 0.04 ≤ x ≤ 0.15).

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The self-rigidification of ionized π-conjugated systems based on two combinations of thiophene (T) and 3,4-Ethylenedioxythiophene (E) is investigated using mass-analyzed ion kinetic energy spectrometry (MIKES) of ions produced from electron impact ionization at 70 eV. The m/z 446 radical cations of the two isomers ETTE and TEET lead to detect m/z 418 and 390 daughter ions. The MIKE spectra differ only by the intensities of these fragment ions.

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Main-Group-Based Electro- and Photoactive Chiral Materials.

Chem Rev

July 2019

Laboratoire MOLTECH-Anjou , UMR 6200 CNRS- Université d'Angers, UFR Sciences, Bât. K, 2 Bd. Lavoisier , 49045 Angers Cedex, France.

This Review discusses the structure-property relationships in chiral molecules, macromolecules (polymers), and supramolecules (crystals, liquid crystals, or thin films) containing main-group elements. Chirality is a major property in our world, having a prominent influence on processes in biology, chemistry, and physics. Its impact in optics due to its interaction with electromagnetic waves gave rise to a multitude of effects, such as the Cotton effect and circularly polarized luminescence, making possible applications such as 3D displays and polarized sunglasses.

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