Weak Coordinating Character of Organosulfonates in Oriented Silica Films: An Efficient Approach for Immobilizing Cationic Metal-Transition Complexes
Iron (II) tris(2,2′-bipyridine) complexes, [Fe(bpy)<sub>3</sub>]<sup>2+</sup>, have been synthesized and immobilized in organosulfonate-functionalized nanostructured silica thin films taking advantage of the stabilization of [Fe(H<sub>2</sub>O)<sub>6</sub...
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MDPI AG
2022-08-01
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author | Samuel Ahoulou Clara Richart Cédric Carteret Sébastien Pillet Neus Vilà Alain Walcarius |
author_facet | Samuel Ahoulou Clara Richart Cédric Carteret Sébastien Pillet Neus Vilà Alain Walcarius |
author_sort | Samuel Ahoulou |
collection | DOAJ |
description | Iron (II) tris(2,2′-bipyridine) complexes, [Fe(bpy)<sub>3</sub>]<sup>2+</sup>, have been synthesized and immobilized in organosulfonate-functionalized nanostructured silica thin films taking advantage of the stabilization of [Fe(H<sub>2</sub>O)<sub>6</sub>]<sup>2+</sup> species by hydrogen bonds to the anionic sulfonate moieties grafted to the silica nanopores. In a first step, thiol-based silica films have been electrochemically generated on indium tin oxide (ITO) substrates by co-condensation of 3-mercaptopropyltrimethoxysilane (MPTMS) and tetraethoxysilane (TEOS). Secondly, the thiol function has been modified to sulfonate by chemical oxidation using hydrogen peroxide in acidic medium as an oxidizing agent. The immobilization of [Fe(bpy)<sub>3</sub>]<sup>2+</sup> complexes has been performed in situ in two consecutive steps: (i) impregnation of the sulfonate functionalized silica films in an aqueous solution of iron (II) sulfate heptahydrate; (ii) dipping of the iron-containing mesostructures in a solution of bipyridine ligands in acetonitrile. The in situ formation of the [Fe(bpy)<sub>3</sub>]<sup>2+</sup> complex is evidenced by its characteristic optical absorption spectrum, and elemental composition analysis using X-ray photoelectron spectroscopy. The measured optical and electrochemical properties of immobilized [Fe(bpy)<sub>3</sub>]<sup>2+</sup> complexes are not altered by confinement in the nanostructured silica thin film. |
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spelling | doaj.art-20529cb7166840949b4647f7f779fe602023-11-23T13:42:03ZengMDPI AGMolecules1420-30492022-08-012717544410.3390/molecules27175444Weak Coordinating Character of Organosulfonates in Oriented Silica Films: An Efficient Approach for Immobilizing Cationic Metal-Transition ComplexesSamuel Ahoulou0Clara Richart1Cédric Carteret2Sébastien Pillet3Neus Vilà4Alain Walcarius5LCPME, CNRS, Universite de Lorraine, F-54000 Nancy, FranceLCPME, CNRS, Universite de Lorraine, F-54000 Nancy, FranceLCPME, CNRS, Universite de Lorraine, F-54000 Nancy, FranceCRM2, CNRS, Universite de Lorraine, F-54000 Nancy, FranceLCPME, CNRS, Universite de Lorraine, F-54000 Nancy, FranceLCPME, CNRS, Universite de Lorraine, F-54000 Nancy, FranceIron (II) tris(2,2′-bipyridine) complexes, [Fe(bpy)<sub>3</sub>]<sup>2+</sup>, have been synthesized and immobilized in organosulfonate-functionalized nanostructured silica thin films taking advantage of the stabilization of [Fe(H<sub>2</sub>O)<sub>6</sub>]<sup>2+</sup> species by hydrogen bonds to the anionic sulfonate moieties grafted to the silica nanopores. In a first step, thiol-based silica films have been electrochemically generated on indium tin oxide (ITO) substrates by co-condensation of 3-mercaptopropyltrimethoxysilane (MPTMS) and tetraethoxysilane (TEOS). Secondly, the thiol function has been modified to sulfonate by chemical oxidation using hydrogen peroxide in acidic medium as an oxidizing agent. The immobilization of [Fe(bpy)<sub>3</sub>]<sup>2+</sup> complexes has been performed in situ in two consecutive steps: (i) impregnation of the sulfonate functionalized silica films in an aqueous solution of iron (II) sulfate heptahydrate; (ii) dipping of the iron-containing mesostructures in a solution of bipyridine ligands in acetonitrile. The in situ formation of the [Fe(bpy)<sub>3</sub>]<sup>2+</sup> complex is evidenced by its characteristic optical absorption spectrum, and elemental composition analysis using X-ray photoelectron spectroscopy. The measured optical and electrochemical properties of immobilized [Fe(bpy)<sub>3</sub>]<sup>2+</sup> complexes are not altered by confinement in the nanostructured silica thin film.https://www.mdpi.com/1420-3049/27/17/5444mesoporous silica filmspolypyridyl metal complexesconfinement effectsmetal ligand coordinationorganic–inorganic hybridsiron-bipyridine derivatives |
spellingShingle | Samuel Ahoulou Clara Richart Cédric Carteret Sébastien Pillet Neus Vilà Alain Walcarius Weak Coordinating Character of Organosulfonates in Oriented Silica Films: An Efficient Approach for Immobilizing Cationic Metal-Transition Complexes Molecules mesoporous silica films polypyridyl metal complexes confinement effects metal ligand coordination organic–inorganic hybrids iron-bipyridine derivatives |
title | Weak Coordinating Character of Organosulfonates in Oriented Silica Films: An Efficient Approach for Immobilizing Cationic Metal-Transition Complexes |
title_full | Weak Coordinating Character of Organosulfonates in Oriented Silica Films: An Efficient Approach for Immobilizing Cationic Metal-Transition Complexes |
title_fullStr | Weak Coordinating Character of Organosulfonates in Oriented Silica Films: An Efficient Approach for Immobilizing Cationic Metal-Transition Complexes |
title_full_unstemmed | Weak Coordinating Character of Organosulfonates in Oriented Silica Films: An Efficient Approach for Immobilizing Cationic Metal-Transition Complexes |
title_short | Weak Coordinating Character of Organosulfonates in Oriented Silica Films: An Efficient Approach for Immobilizing Cationic Metal-Transition Complexes |
title_sort | weak coordinating character of organosulfonates in oriented silica films an efficient approach for immobilizing cationic metal transition complexes |
topic | mesoporous silica films polypyridyl metal complexes confinement effects metal ligand coordination organic–inorganic hybrids iron-bipyridine derivatives |
url | https://www.mdpi.com/1420-3049/27/17/5444 |
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