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Ling Peng - One of the best experts on this subject based on the ideXlab platform.

Fabrice Odobel - One of the best experts on this subject based on the ideXlab platform.

  • chemistry on the electrodes post functionalization and stability enhancement of anchored dyes on mesoporous metal oxide photoelectrochemical cells with copper free Huisgen cycloaddition Reaction
    Journal of Materials Chemistry, 2020
    Co-Authors: Yousra Bentounsi, Errol Blart, Yann Pellegrin, Konstantinos Seintis, Dorine Ameline, Stephane Diring, David Provost, Damien Cossement, Eric Vauthey, Fabrice Odobel
    Abstract:

    Hybrid materials consisting of nanocrystalline metal oxide films coated with molecules have considerable implications for the development of optoelectronic devices. We report on a straightforward and versatile procedure to engineer stable layers made of molecules chemisorbed on the surface of mesoporous inorganic metal oxides. The procedure is based on a thermal copper-free Huisgen Reaction, which is directly conducted on TiO2 or NiO nanocrystalline films, between already bound diketopyrrolopyrrole sensitizers substituted by two azido groups and a crosslinking agent consisting of a tetrapropiolate ester. The procedure is mild and simple and does not require a catalyst, since quantitative conversion is obtained by a simple heating of the photoelectrode into a solution of the crosslinking agent. The photoelectrodes were characterized by ToF-SIMS, femtosecond transient absorption spectroscopy, electrochemistry and were finally used to fabricate dye-sensitized solar cells with iodide/triiodide and cobalt trisbipyridine complexes as redox mediators. Important increased stability of the crosslinked films was demonstrated by desorption and cyclic voltammetry experiments. Transient absorption spectroscopy and photovoltaic measurements showed that the dyes keep their initial photoelectrochemical properties upon crosslinking. This bottom-up approach is certainly broadly applicable and opens the possibility to make “chemistry on the electrode” to functionalize and crosslink dyes with any component.

  • Simpler and more efficient strategy to stabilize the chromophore orientation in electro-optic polymers with copper-free thermal Huisgen Reaction
    'Elsevier BV', 2011
    Co-Authors: C. Cabanetos, Errol Blart, Véronique Montembault, Y. Pellegrin, L. Fontaine, F. Adamietz, V. Rodriguez, Fabrice Odobel
    Abstract:

    A new strategy is proposed to stabilize the electro-optic (EO) activity of second-order materials using copper-free thermal Huisgen 1,3-dipolar cross-linking Reaction. It consists in freezing the chromophores orientation after the poling process by a cross-linking Reaction based on the 1,3-dipolar cycloaddition between an azide and an alkyne. To reach this goal, the synthesis of new methacrylate type polymers bearing a derivative of Disperse Red 1 chromophore was performed. The polymeric structure is bearing a cross-linkable function on its backbone and the complementary reactive function is brought by a small molecule called “doping agent” (DA), containing several complementary cross-linking groups, evenly distributed in the polymer film. Materials have been prepared and exhibit large second-order nonlinear optical coefficients (d33) up to 60 pm/V at the fundamental wavelength of 1064 nm. Moreover, the thermal stability of the orientation of the chromophores could reach 150 °C upon cross-linking with such materials, which is higher than previously described cross-linkable EO polymers based on this Reaction. Furthermore, this new strategy widens the possibilities offered by copper-free thermal Huisgen 1,3-dipolar cycloaddition as cross-linking Reaction for EO polymers

  • scope and limitation of the copper free thermal Huisgen cross linking Reaction to stabilize the chromophores orientation in electro optic polymers
    Polymer Chemistry, 2011
    Co-Authors: Annabelle Scarpaci, Vincent Rodriguez, Errol Blart, Véronique Montembault, Laurent Fontaine, Clement Cabanetos, Yann Pellegrin, Fabrice Odobel
    Abstract:

    New methacrylate copolymers incorporating two complementary thermally cross-linkable groups (azide or ethynyl) for implementation in electro-optic devices were synthesized and their nonlinear optical properties were investigated. These copolymers were prepared from a monomer containing Disperse Red 1 (DR1) as active NLO chromophore which is end substituted either by an azide or ethynyl group connected via a rigid (phenyl) or flexible spacer (alkyl chain). The second monomer is either a trimethylsilyl-propargyl methacrylate, or an azidopropyl methacrylate or a trimethylsilyl-phenyl methacrylate. The determination of the reactivity ratios showed that the monomer containing the DR1 chromophore is more reactive than trimethylsilyl-propargyl methacrylate. The cross-linking temperatures of these polymers range from 150 °C to 187 °C depending on the rigidity of the spacers connecting the cross-linkable units. These polymers displayed relatively high macroscopic electro-optic stability, enhanced upon cross-linking by more than 40 °C relative to non-cross-linked polymers. The results underscore the importance of the flexibility of the spacers to achieve the stable bulk electro-optic response. While rigidity is favorable to maintain the orientation of the chromophores, the optimal polymer is the one containing a flexible and a rigid spacer, since the mobility of the reactive groups is a key parameter which guarantees a high cross-linking conversion within the polymer. This study demonstrates the versatility of this new cross-linking process because we showed that the reactive groups (azide or trimethylsilylacetylated groups) can be interconverted (on the chromophore or as polymer side chain) with no change on the overall electro-optic activity and its thermal stability. Furthermore, preliminary kinetic study indicates that the Huisgen Reaction rate can be controlled by the substituent on the ethynyl group opening the possibility to tune the cross-linking temperature by the careful choice of this substituent.

  • postfunctionalization of poly propargyl methacrylate using copper catalyzed 1 3 dipolar Huisgen cycloaddition an easy route to electro optic materials
    Journal of Polymer Science Part A, 2009
    Co-Authors: Annabelle Scarpaci, Vincent Rodriguez, Errol Blart, Fabrice Odobel, Véronique Montembault, Laurent Fontaine, Clement Cabanetos
    Abstract:

    A one-pot synthetic route based on copper-catalyzed Huisgen Reaction has been developed to functionalize a methacrylate propargylic polymer with azido-substituted moieties. This procedure was used for the preparation of electro-optic materials containing well-known Disperse Red One (DR1) chromophores along with bulky adamantyl moieties (Adam). The postfunctionalization of the propargylic polymer was successfully achieved using different molar ratios of DR1/Adam. These novel polymers exhibit high glass transition temperature owing to the rigid structure of adamantyl units. Moreover, the second harmonic generation measurements demonstrated the effectiveness of adamantyl groups to act as insulating shield limiting thus the electrostatic interactions between chromophores. Indeed, higher optimal chromophore concentration (50 mol %) than in conventional DR1-containing polymers (30 mol %) allowed us to increase the d33 coefficient up to 92 pm/V. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5652–5660, 2009

  • A new crosslinkable system based on thermal Huisgen Reaction to enhance the stability of electro-optic polymers.
    Chemical communications (Cambridge, England), 2009
    Co-Authors: Annabelle Scarpaci, Vincent Rodriguez, Errol Blart, Véronique Montembault, Laurent Fontaine, Fabrice Odobel
    Abstract:

    The thermal Huisgen cycloaddition Reaction is a new and efficient process to crosslink electro-optic polymers, since it leads to an effective increase of the thermal alignment stability of the NLO chromophores.

Yi Xia - One of the best experts on this subject based on the ideXlab platform.

Errol Blart - One of the best experts on this subject based on the ideXlab platform.

  • chemistry on the electrodes post functionalization and stability enhancement of anchored dyes on mesoporous metal oxide photoelectrochemical cells with copper free Huisgen cycloaddition Reaction
    Journal of Materials Chemistry, 2020
    Co-Authors: Yousra Bentounsi, Errol Blart, Yann Pellegrin, Konstantinos Seintis, Dorine Ameline, Stephane Diring, David Provost, Damien Cossement, Eric Vauthey, Fabrice Odobel
    Abstract:

    Hybrid materials consisting of nanocrystalline metal oxide films coated with molecules have considerable implications for the development of optoelectronic devices. We report on a straightforward and versatile procedure to engineer stable layers made of molecules chemisorbed on the surface of mesoporous inorganic metal oxides. The procedure is based on a thermal copper-free Huisgen Reaction, which is directly conducted on TiO2 or NiO nanocrystalline films, between already bound diketopyrrolopyrrole sensitizers substituted by two azido groups and a crosslinking agent consisting of a tetrapropiolate ester. The procedure is mild and simple and does not require a catalyst, since quantitative conversion is obtained by a simple heating of the photoelectrode into a solution of the crosslinking agent. The photoelectrodes were characterized by ToF-SIMS, femtosecond transient absorption spectroscopy, electrochemistry and were finally used to fabricate dye-sensitized solar cells with iodide/triiodide and cobalt trisbipyridine complexes as redox mediators. Important increased stability of the crosslinked films was demonstrated by desorption and cyclic voltammetry experiments. Transient absorption spectroscopy and photovoltaic measurements showed that the dyes keep their initial photoelectrochemical properties upon crosslinking. This bottom-up approach is certainly broadly applicable and opens the possibility to make “chemistry on the electrode” to functionalize and crosslink dyes with any component.

  • new cross linkable polymers with Huisgen Reaction incorporating high μβ chromophores for second order nonlinear optical applications
    Chemistry of Materials, 2012
    Co-Authors: Clement Cabanetos, Errol Blart, Véronique Montembault, Wissam Bentoumi, Virginie Silvestre, Yann Pellegrin, Alberto Barsella, Kokou D Dorkenoo, Yann Bretonniere, Chantal Andraud
    Abstract:

    We report herein the synthesis, the functionalization, and the successful radical polymerization of very nonlinear optical (NLO) active push–pull polyene chromophores (CPO). Second, the thermal Huisgen cyclo-addition cross-linking Reaction was implemented, and it proved to be fully compatible with a polyene-based push–pull chromophore. Toward this goal, PMMA-co-CPO-3 and two cross-linkable polymers (PCC1-CPO-3 and PCC2-CPO-3) were first prepared and characterized by a modified Teng and Man technique performed in transmission. These first series of polymers were not compatible with the applied poling conditions because an irreversible film degradation was systematically observed at a temperature significantly lower than the cross-linking temperature. Consequently, a second series of polymers was prepared, in which the cross-linking temperature was decreased by functionalizing acetylenic moieties with ester electron withdrawing groups, which decrease the activation energy of the thermal Huisgen cyclo-additi...

  • Simpler and more efficient strategy to stabilize the chromophore orientation in electro-optic polymers with copper-free thermal Huisgen Reaction
    'Elsevier BV', 2011
    Co-Authors: C. Cabanetos, Errol Blart, Véronique Montembault, Y. Pellegrin, L. Fontaine, F. Adamietz, V. Rodriguez, Fabrice Odobel
    Abstract:

    A new strategy is proposed to stabilize the electro-optic (EO) activity of second-order materials using copper-free thermal Huisgen 1,3-dipolar cross-linking Reaction. It consists in freezing the chromophores orientation after the poling process by a cross-linking Reaction based on the 1,3-dipolar cycloaddition between an azide and an alkyne. To reach this goal, the synthesis of new methacrylate type polymers bearing a derivative of Disperse Red 1 chromophore was performed. The polymeric structure is bearing a cross-linkable function on its backbone and the complementary reactive function is brought by a small molecule called “doping agent” (DA), containing several complementary cross-linking groups, evenly distributed in the polymer film. Materials have been prepared and exhibit large second-order nonlinear optical coefficients (d33) up to 60 pm/V at the fundamental wavelength of 1064 nm. Moreover, the thermal stability of the orientation of the chromophores could reach 150 °C upon cross-linking with such materials, which is higher than previously described cross-linkable EO polymers based on this Reaction. Furthermore, this new strategy widens the possibilities offered by copper-free thermal Huisgen 1,3-dipolar cycloaddition as cross-linking Reaction for EO polymers

  • scope and limitation of the copper free thermal Huisgen cross linking Reaction to stabilize the chromophores orientation in electro optic polymers
    Polymer Chemistry, 2011
    Co-Authors: Annabelle Scarpaci, Vincent Rodriguez, Errol Blart, Véronique Montembault, Laurent Fontaine, Clement Cabanetos, Yann Pellegrin, Fabrice Odobel
    Abstract:

    New methacrylate copolymers incorporating two complementary thermally cross-linkable groups (azide or ethynyl) for implementation in electro-optic devices were synthesized and their nonlinear optical properties were investigated. These copolymers were prepared from a monomer containing Disperse Red 1 (DR1) as active NLO chromophore which is end substituted either by an azide or ethynyl group connected via a rigid (phenyl) or flexible spacer (alkyl chain). The second monomer is either a trimethylsilyl-propargyl methacrylate, or an azidopropyl methacrylate or a trimethylsilyl-phenyl methacrylate. The determination of the reactivity ratios showed that the monomer containing the DR1 chromophore is more reactive than trimethylsilyl-propargyl methacrylate. The cross-linking temperatures of these polymers range from 150 °C to 187 °C depending on the rigidity of the spacers connecting the cross-linkable units. These polymers displayed relatively high macroscopic electro-optic stability, enhanced upon cross-linking by more than 40 °C relative to non-cross-linked polymers. The results underscore the importance of the flexibility of the spacers to achieve the stable bulk electro-optic response. While rigidity is favorable to maintain the orientation of the chromophores, the optimal polymer is the one containing a flexible and a rigid spacer, since the mobility of the reactive groups is a key parameter which guarantees a high cross-linking conversion within the polymer. This study demonstrates the versatility of this new cross-linking process because we showed that the reactive groups (azide or trimethylsilylacetylated groups) can be interconverted (on the chromophore or as polymer side chain) with no change on the overall electro-optic activity and its thermal stability. Furthermore, preliminary kinetic study indicates that the Huisgen Reaction rate can be controlled by the substituent on the ethynyl group opening the possibility to tune the cross-linking temperature by the careful choice of this substituent.

  • postfunctionalization of poly propargyl methacrylate using copper catalyzed 1 3 dipolar Huisgen cycloaddition an easy route to electro optic materials
    Journal of Polymer Science Part A, 2009
    Co-Authors: Annabelle Scarpaci, Vincent Rodriguez, Errol Blart, Fabrice Odobel, Véronique Montembault, Laurent Fontaine, Clement Cabanetos
    Abstract:

    A one-pot synthetic route based on copper-catalyzed Huisgen Reaction has been developed to functionalize a methacrylate propargylic polymer with azido-substituted moieties. This procedure was used for the preparation of electro-optic materials containing well-known Disperse Red One (DR1) chromophores along with bulky adamantyl moieties (Adam). The postfunctionalization of the propargylic polymer was successfully achieved using different molar ratios of DR1/Adam. These novel polymers exhibit high glass transition temperature owing to the rigid structure of adamantyl units. Moreover, the second harmonic generation measurements demonstrated the effectiveness of adamantyl groups to act as insulating shield limiting thus the electrostatic interactions between chromophores. Indeed, higher optimal chromophore concentration (50 mol %) than in conventional DR1-containing polymers (30 mol %) allowed us to increase the d33 coefficient up to 92 pm/V. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5652–5660, 2009

Corrêa, Lucília Zeymer Alves - One of the best experts on this subject based on the ideXlab platform.

  • Síntese de compostos 1,2,3-triazólicos : potenciais inibidores da proteína auxiliar Nef do vírus HIV-1
    2012
    Co-Authors: Corrêa, Lucília Zeymer Alves
    Abstract:

    O vírus da imunodeficiência humana infecta linfócitos T, que possuem o receptor CD 4 na membrana plasmática. Inicialmente, o CD 4 é responsável pela entrada do vírus na célula hospedeira. Em um segundo momento, ocorre a modulação negativa do CD 4 pela proteína auxiliar Nef do vírus HIV-1, o que possibilita a saída do vírus para infectar outra célula. O antibiótico Ikarugamicina impede a modulação negativa do CD4 pela proteína auxiliar Nef e reestabelece o nível de CD 4 na membrana plasmática, mas é citotóxico em testes in vitro. Inibidores da proteína auxiliar Nef vêm sendo amplamente estudados como possíveis fármacos para o tratamento antirretroviral. O objetivo deste trabalho é a síntese de possíveis inibidores da proteína auxiliar Nef do vírus HIV -1. A partir de estudos de interação molecular, propusemos a síntese de seis moléculas, que contêm os grupos 3-amino-1,2,4-triazol, uracila ou 1,2,3-triazol, como possíveis inibidores da proteína auxiliar Nef do vírus HIV-1. Após análise retrossintética, diversas rotas foram propostas para a síntese das moléculas. Após várias tentativas de síntese, não se obteve sucesso na síntese da molécula com o grupo 3-amino-1,2,4-triazol, e da molécula com o grupo uracila. Um total de quatro moléculas contendo o anel 1,2,3-triazólico foram sintetizadas por rota sintética direta, obtendo-se excelentes rendimentos. A síntese envolveu a preparação do grupo azida, seguida por reação de Huisgen – reação click – e acoplamento com DCC/DMAP. ______________________________________________________________________________ ABSTRACTThe human immunodeficiency virus infects T lymphocytes that have the CD4 receptor on the plasma membrane. Initially, CD4 is responsible for virus entry into the host cell. In a second stage, the CD 4 downregulation by the auxiliary protein of HIV-1 Nef occurs, allowing the exit of the virus to infect another cell. The antibiotic Ikarugamycin prevents downregulation of CD 4 by the Nef auxiliary protein and restores the level of CD4 at the plasma membrane, but in vitro tests it is cytotoxic. Nef inhibitors have been investigated as potential drugs for antiretroviral treatment. The aim of this work is the synthesis of potential inhibitors of auxiliary protein HIV-1 Nef. Based on studies of molecular interaction we proposed the synthesis of six molecules, which contain the groups 3-amino-1,2,4-triazole, 1,2,3-triazole or uracil as potential inhibitors of the auxiliary protein HIV -1 Nef. After retrosynthetic analysis, several routes have been proposed for the synthesis of these molecules. Several attempts to synthesize molecules with the 3-amino-1,2,4-triazole and uracil groups, were performed without success. The molecules containing 1,2,3-triazole ring were synthesized by a direct synthetic route with excellent yields. The synthesis involved the preparation of the azide group, followed by the Huisgen Reaction – click Reaction – and DCC/DMAP coupling

  • Síntese de compostos 1,2,3-triazólicos : potenciais inibidores da proteína auxiliar Nef do vírus HIV-1
    2011
    Co-Authors: Corrêa, Lucília Zeymer Alves
    Abstract:

    Dissertação (mestrado)—Universidade de Brasília, Instituto de Química, 2011.O vírus da imunodeficiência humana infecta linfócitos T, que possuem o receptor CD 4 na membrana plasmática. Inicialmente, o CD 4 é responsável pela entrada do vírus na célula hospedeira. Em um segundo momento, ocorre a modulação negativa do CD 4 pela proteína auxiliar Nef do vírus HIV-1, o que possibilita a saída do vírus para infectar outra célula. O antibiótico Ikarugamicina impede a modulação negativa do CD4 pela proteína auxiliar Nef e reestabelece o nível de CD 4 na membrana plasmática, mas é citotóxico em testes in vitro. Inibidores da proteína auxiliar Nef vêm sendo amplamente estudados como possíveis fármacos para o tratamento antirretroviral. O objetivo deste trabalho é a síntese de possíveis inibidores da proteína auxiliar Nef do vírus HIV -1. A partir de estudos de interação molecular, propusemos a síntese de seis moléculas, que contêm os grupos 3-amino-1,2,4-triazol, uracila ou 1,2,3-triazol, como possíveis inibidores da proteína auxiliar Nef do vírus HIV-1. Após análise retrossintética, diversas rotas foram propostas para a síntese das moléculas. Após várias tentativas de síntese, não se obteve sucesso na síntese da molécula com o grupo 3-amino-1,2,4-triazol, e da molécula com o grupo uracila. Um total de quatro moléculas contendo o anel 1,2,3-triazólico foram sintetizadas por rota sintética direta, obtendo-se excelentes rendimentos. A síntese envolveu a preparação do grupo azida, seguida por reação de Huisgen – reação click – e acoplamento com DCC/DMAP. ______________________________________________________________________________ ABSTRACTThe human immunodeficiency virus infects T lymphocytes that have the CD4 receptor on the plasma membrane. Initially, CD4 is responsible for virus entry into the host cell. In a second stage, the CD 4 downregulation by the auxiliary protein of HIV-1 Nef occurs, allowing the exit of the virus to infect another cell. The antibiotic Ikarugamycin prevents downregulation of CD 4 by the Nef auxiliary protein and restores the level of CD4 at the plasma membrane, but in vitro tests it is cytotoxic. Nef inhibitors have been investigated as potential drugs for antiretroviral treatment. The aim of this work is the synthesis of potential inhibitors of auxiliary protein HIV-1 Nef. Based on studies of molecular interaction we proposed the synthesis of six molecules, which contain the groups 3-amino-1,2,4-triazole, 1,2,3-triazole or uracil as potential inhibitors of the auxiliary protein HIV -1 Nef. After retrosynthetic analysis, several routes have been proposed for the synthesis of these molecules. Several attempts to synthesize molecules with the 3-amino-1,2,4-triazole and uracil groups, were performed without success. The molecules containing 1,2,3-triazole ring were synthesized by a direct synthetic route with excellent yields. The synthesis involved the preparation of the azide group, followed by the Huisgen Reaction – click Reaction – and DCC/DMAP coupling