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163 results on '"Bellec, Nathalie"'

3. Non‐Linear Optical Activity of Chiral Bipyrimidine‐Based Thin Films

Author

Nicolas, Prescillia, primary, Abdallah, Stephania, additional, Dok, Ahmet, additional, de Coene, Yovan, additional, Jeannin, Olivier, additional, Bellec, Nathalie, additional, Malval, Jean-Pierre, additional, Verbiest, Thierry, additional, Clays, Koen, additional, Van Cleuvenbergen, Stijn, additional, Bilgin-Eran, Belkiz, additional, Akdas-Kiliç, Huriye, additional, and Camerel, Franck, additional

Published
2024
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4. Non‐Linear Optical Activity of Chiral Bipyrimidine‐Based Thin Films.

Author

Nicolas, Prescillia, Abdallah, Stephania, Dok, Ahmet, de Coene, Yovan, Jeannin, Olivier, Bellec, Nathalie, Malval, Jean‐Pierre, Verbiest, Thierry, Clays, Koen, Van Cleuvenbergen, Stijn, Bilgin‐Eran, Belkiz, Akdas‐Kiliç, Huriye, and Camerel, Franck

Subjects
NONLINEAR optical spectroscopy, THIN films, THIRD harmonic generation, NONLINEAR optical materials, POLARIZATION microscopy, SMALL-angle X-ray scattering, OPTICAL rotation
Abstract

An original series of bipyrimidine‐based chromophores featuring alkoxystyryl donor groups bearing short chiral (S)‐2‐methylbutyl chains in positions 4, 3,4 and 3,5, connected to electron‐accepting 2,2‐bipyrimidine rings, has been developed. Their linear and non‐linear optical properties were studied using a variety of techniques, including one‐ and two‐photon absorption spectroscopy, fluorescence measurements, as well as Hyper‐Rayleigh scattering to determine the first hyperpolarizabilities. Their electronic and geometrical properties were rationalized by TD‐DFT calculations. The thermal properties of the compounds were also investigated by a combination of polarized light optical microscopy, differential scanning calorimetry measurements and small‐angle X‐ray scattering experiments. The derivatives were found not to have mesomorphic properties, but to exhibit melting temperatures or cold crystallization behavior that enabled the isolation of well‐organized thin films. The nonlinear optical properties of amorphous or crystalline thin films were studied by wide‐field second harmonic generation and multiphoton fluorescence imaging, confirming that non‐centrosymmetric crystal organization enables strong second and third harmonic generation. This new series confirms that our strategy of functionalizing 3D organic octupoles with short chiral chains to generate non‐centrosymmetric organized thin films enables the development of highly second order nonlinear optical active materials without the use of corona‐poling or tedious deposition techniques. [ABSTRACT FROM AUTHOR]

Published
2024
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5. New Multifunctional Bipyrimidine‐Based Chromophores for NLO‐Active Thin‐Film Preparation**

Author

Bora, Umut, primary, Abdallah, Stephania, additional, Mhanna, Rana, additional, Nicolas, Prescillia, additional, Dok, Ahmet, additional, de Coene, Yovan, additional, Van Cleuvenbergen, Stijn, additional, Jeannin, Olivier, additional, Malval, Jean‐Pierre, additional, Clays, Koen, additional, Bellec, Nathalie, additional, Ocak, Hale, additional, Bilgin‐Eran, Belkis, additional, Camerel, Franck, additional, and Akdas‐Kiliç, Huriye, additional

Published
2023
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6. Investigations of the Photothermal Properties of a Series of Molecular Gold-bis(dithiolene) Complexes Absorbing in the NIR-III Region

Author

Pluta, Jean-Baptiste, Guechaichia, Romain, Vacher, Antoine, Bellec, Nathalie, Cammas-Marion, Sandrine, Camerel, Franck, Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), N.B., S.C.-M. and F.C. acknowledge the CNRS, the University of Rennes and the 'Ligue contre le cancer CD 35, 45, 85' for their financial support. This work was also partly funded by France Life Imaging (grant ANR-11-INBS-0006)., and ANR-11-INBS-0006,FLI,France Life Imaging(2011)

Subjects
Molecular, Gold-bis(dithiolene) complexes, Nanoparticles, [CHIM]Chemical Sciences, Photothermal index
Abstract

International audience; The photothermal properties of a series of neutral radical gold-bis(dithiolene) complexes absorbing in the near-infrared-III window (1550 - 1870 nm) have been investigated. This class of complexes was found to be good photothermal agents (PTAs) in toluene under 1600 nm laser irradiation with photothermal efficiencies around 40 and 60% depending on the nature of the dithiolene ligand. To the best of our knowledge, these complexes are the first small molecular photothermal agents to absorb so far into the near infrared. To test their applicability in water, these hydrophobic complexes have been encapsulated into nanoparticles constituted by amphiphilic block-copolymers. Stable suspensions of polymeric nanoparticles (NPs) encapsulating the gold-bis(dithiolene) complexes have been prepared which show a diameter around 100 nm. The encapsulation rate was found to be strongly dependent on the nature of the dithiolene ligands. The photothermal properties of the aqueous suspensions containing gold-bis(dithiolene) complexes were then studied under 1600 nm laser irradiation. These studies demonstrate that water has strong photothermal activity in the NIR-III region that, cannot be overcome even with the addition of gold complexes displaying good photothermal properties.

Published
2023
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8. New Multifunctional Bipyrimidine‐Based Chromophores for NLO‐Active Thin‐Film Preparation**.

Author

Bora, Umut, Abdallah, Stephania, Mhanna, Rana, Nicolas, Prescillia, Dok, Ahmet, de Coene, Yovan, Van Cleuvenbergen, Stijn, Jeannin, Olivier, Malval, Jean‐Pierre, Clays, Koen, Bellec, Nathalie, Ocak, Hale, Bilgin‐Eran, Belkis, Camerel, Franck, and Akdas‐Kiliç, Huriye

Subjects
SMECTIC liquid crystals, SMALL-angle X-ray scattering, CHROMOPHORES, MICROSCOPY, SECOND harmonic generation, OPTICAL properties, DIFFERENTIAL scanning calorimetry
Abstract

New synthesized bipyrimidine‐based chromophores presenting alkoxystyryl donor groups carrying aliphatic achiral and chiral chains in the 4 position, connected to electron‐accepting 2,2‐bipyrimidine cores have been synthesized. Their linear and nonlinear optical (NLO) properties were investigated as well as their mesomorphic properties by various techniques (light‐transmission measurements, polarized‐light optical microscopy, differential scanning calorimetry measurements and two‐photon excited fluorescence). The derivatives with achiral linear carbon chains were found to exhibit liquid‐crystal properties with the formation smectic phases over large temperature ranges, which were confirmed by small‐angle X‐ray scattering analysis via stacking models. The nonlinear optical properties in the solid state for derivatives with C14 and the citronellol chains have been studied by wide‐field second‐harmonic generation and multi‐photon fluorescence imaging, confirming centrosymmetry for these achiral mesogens and their excellent third‐order nonlinearity whereas the chiral compound exhibits non‐centrosymmetric organization resulting in a strong Second Harmonic Generation at the crystal state. [ABSTRACT FROM AUTHOR]

Published
2024
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13. Crown ether vinylogous tetrathiafulvalene receptors: Complexation interference on the molecular movements triggered by electron transfer

Author

Massue, Julien, Bellec, Nathalie, Guerro, Michel, Bergamini, Jean-Francois, Hapiot, Philippe, and Lorcy, Dominique

Subjects
Electron transport -- Analysis, Biological sciences, Chemistry
Abstract

A series of crown ether substituted vinylogous tetrathiafulvalenes (TTFVs) is synthesized via oxidative coupling of bisdithiafulvenes. The rigidification of the crown ether ring after complexation has appeared as a decrease of the apparent electron-transfer kinetics and has little effect on the thermodynamics as the crown ether is far from the redox center.

Published
2007

14. Electroactive ligands: The first metal complexes of tetrathiafulvenyl-acetylacetonate

Author

Massue, Julien, Bellec, Nathalie, Chopin, Stephanie, Rolsenel, Thierry, Clerac, Rodalphe, and Lorcy, Domonique

Subjects
Acetone -- Chemical properties, Coordination compounds -- Chemical properties, Oxidation-reduction reaction -- Analysis, Chemistry
Abstract

The synthesis and the chelating ability of the tetrathiafulvenyl-acerylacetonate anion are investigated in regard to metal M(super H) cation (M(super h) = Ni, Zn) giving rise to the first metal complexes involving such rodox-active ligands. Electrochemical investigation, associated with the structural analysis of these complexes, evidence intramolecular interactions between two tetrathiafulvalene (TTF) cores of a complex.

Published
2005

17. Porphyrazinediols: synthesis, characterization, and complexation to group IVB metallocenes

Author

Bellec, Nathalie, Montalban, Antonio Garrido, Williams, D. Bradley G., Cook, Andrew S., Anderson, Mairin E., Feng, Xidong, Barrett, Anthony G.M., and Hoffman, Brian M.

Subjects
Organic compounds -- Synthesis, Organometallic compounds -- Analysis, Organometallic chemistry -- Research, Ligands -- Analysis, Biological sciences, Chemistry
Abstract

Research describes the synthesis of porphyrazinediols, their conversion into solitaire complexes, and chemical oxidation of the polydentate noninnocent macrocycles. Results demonstrate that porphyrazinediols are a novel class of redox-active ligands whose diol chelating group is directly attached at the beta-positions of the macrocycle.

Published
2000

18. Vinylmercury hydrides: synthesis and spectroscopic characterization

Author

Guillemin, Jean-Claude, Bellec, Nathalie, Szetsi, Sandor Kis, Nyulaszi, Laszlo, and Veszpremi, Tamas

Subjects
Mercury compounds -- Analysis, Heavy metals -- Analysis, Chemistry
Abstract

The chemoselective reduction of vinylmercury chlorides with tributylstannane and a radical inhibitor produced several vinylmercury hydrides. The vinylmercury hydrides are composed of a mercury unit with a bonding angle of 180 degrees. The HgH bond of the methylmercury hydride has the lowest harmonic frequency among the vinylmercury hydrides. Diethenylmercury has the largest Hg-C bond shortening compared to the monosubstituted compounds.

Published
1996

21. IPT: An Index to Rank Molecular Photothermal Agents.

Author

Ciancone, Mathieu, Bellec, Nathalie, and Camerel, Franck

Subjects
*PHOTOTHERMAL effect, *ABSORPTION coefficients
Abstract

Recently, a large variety of photothermal agents have been developed and are currently under study, owing to their wide range of applications. Nonetheless, a comparison of their relative performances remains a challenge, and it appears that no tool is yet available for rationalizing the data reported in the literature. Indeed, we demonstrate in this paper that neither the temperature increase (ΔT) nor the photothermal efficiency (η) are sufficient to account for the performance of a photothermal agent. From this observation, we propose that a new index, IPTmax, could be used, in order to properly rank molecular photothermal agents according to their efficacy for converting light into heat, in a similar fashion that brilliance is used to compare luminescence properties. [ABSTRACT FROM AUTHOR]

Published
2020
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23. Stable Metallic State of a Neutral-Radical Single-Component Conductor at Ambient Pressure

Author

Ministerio de Economía y Competitividad (España), Generalitat de Catalunya, Fonds National de la Recherche Luxembourg, Le Gal, Yann, Roisnel, Thierry, Auban-Senzier, Pascale, Bellec, Nathalie, Íñiguez, Jorge, Canadell, Enric, Lorcy, Dominique, Ministerio de Economía y Competitividad (España), Generalitat de Catalunya, Fonds National de la Recherche Luxembourg, Le Gal, Yann, Roisnel, Thierry, Auban-Senzier, Pascale, Bellec, Nathalie, Íñiguez, Jorge, Canadell, Enric, and Lorcy, Dominique

Abstract

Molecular metals have been essentially obtained with tetrathiafulvalene (TTF)-based precursors, either with multicomponent ionic materials or, in a few instances, with single-component systems. In that respect, gold bis- (dithiolene) complexes, in their neutral radical state, provide a prototype platform toward such single-component conductors. Herein we report the first single-component molecular metal under ambient pressure derived from such Au complexes without any TTF backbone. This complex exhibits a conductivity of 750 S·cm−1 at 300 K up to 3800 S·cm−1 at 4 K. First-principles electronic structure calculations show that the striking stability of the metallic state finds its origin in sizable internal electron transfer from the SOMO-1 to the SOMO of the complex as well as in substantial interstack and interlayer interactions.

Published
2018

26. A single-component molecular metal based on a thiazole dithiolate gold complex

Author

Tenn, Nadine, Bellec, Nathalie, Jeannin, Olivier, Piekara-Sady, Lidia, Auban-Senzier, Pascale, Iniguez, Jorge, Canade, Enric, and Lorcy, Dominique

Subjects
Density functionals -- Usage, Diazo compounds -- Chemical properties, Diazo compounds -- Electric properties, Gold -- Chemical properties, Gold -- Electric properties, Organometallic compounds -- Structure, Organometallic compounds -- Chemical properties, Organometallic compounds -- Electric properties, Chemistry
Abstract

A single component molecular conductor is isolated from electrocrystallization of the monoanionic gold bis(dithiolene) complex based on the N-ethyl-1,3-thiazoline-2-thione-4,5-dithiolate (Et-thiazdt) ligand. First-principles density functional theory (DFT) calculations have shown that the ground state is antiferromagnetic with a very small band gap.

Published
2009

30. Single-Component Conductors: A Sturdy Electronic Structure Generated by Bulky Substituents

Author

Agence Nationale de la Recherche (France), Ministerio de Economía y Competitividad (España), Generalitat de Catalunya, Filatre-Furcate, Agathe, Bellec, Nathalie, Jeannin, Olivier, Auban-Senzier, Pascale, Fourmigué, Marc, Íñiguez, Jorge, Canadell, Enric, Brière, Benjamin, Ta Phuoc, Vinh, Lorcy, Dominique, Agence Nationale de la Recherche (France), Ministerio de Economía y Competitividad (España), Generalitat de Catalunya, Filatre-Furcate, Agathe, Bellec, Nathalie, Jeannin, Olivier, Auban-Senzier, Pascale, Fourmigué, Marc, Íñiguez, Jorge, Canadell, Enric, Brière, Benjamin, Ta Phuoc, Vinh, and Lorcy, Dominique

Published
2016

37. Variable Magnetic Interactions between S = 1/2 Cation Radical Salts of Functionalizable Electron-Rich Dithiolene and Diselenolene Cp2Mo Complexes

Author

Bsaibess, Talia, primary, Guerro, Michel, additional, Le Gal, Yann, additional, Sarraf, Daad, additional, Bellec, Nathalie, additional, Fourmigué, Marc, additional, Barrière, Frédéric, additional, Dorcet, Vincent, additional, Guizouarn, Thierry, additional, Roisnel, Thierry, additional, and Lorcy, Dominique, additional

Published
2013
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40. Structure–Property Relationships in PtII Diimine‐Dithiolate Nonlinear Optical Chromophores Based on Arylethylene‐1,2‐dithiolate and 2‐Thioxothiazoline‐4,5‐dithiolate

Author

Pintus, Anna, primary, Aragoni, M. Carla, additional, Bellec, Nathalie, additional, Devillanova, Francesco A., additional, Lorcy, Dominique, additional, Isaia, Francesco, additional, Lippolis, Vito, additional, Randall, Rebecca A. M., additional, Roisnel, Thierry, additional, Slawin, Alexandra M. Z., additional, Woollins, J. Derek, additional, and Arca, Massimiliano, additional

Published
2012
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