Maitena Ocafrain
University of Angers
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Publication
Featured researches published by Maitena Ocafrain.
Journal of Materials Chemistry | 2004
Bruno Jousselme; Philippe Blanchard; Maitena Ocafrain; Magali Allain; Eric Levillain; Jean Roncali
The synthesis of a series of bithiophenic precursors of electrogenerated conjugated polymers functionalized by bipyridine ligands is described. The precursor structure involves two polymerizable groups attached at both ends of a bipyridine ligand and fixed at an internal β-position of thiophene via an alkylsulfanyl or alkoxy spacer. Electrochemical and optical data show that the low polymerization potential resulting from the association of 3,4-ethylenedioxythiophene (EDOT) and alkylsulfanyl or alkoxy thiophene combined with the multi-site polymerization approach allows a straightforward electrosynthesis of extensively conjugated and stable functionalized polymers. On the basis of these results, iron and ruthenium complexes of these precursors have been synthesized and electropolymerized. The analysis of the electrochemical behavior of the resulting polymers shows that they exhibit the typical electrochemical signature of both the conjugated polythiophene backbone and the immobilized metal complex.
Chemical Communications | 2010
Sandrine Karpe; Maitena Ocafrain; Kacem Smaali; S. Lenfant; Dominique Vuillaume; Philippe Blanchard; Jean Roncali
Immobilization of an azobenzene-bithiophene compound on a gold surface leads to self-assembled monolayers with photoswitchable electrical properties.
New Journal of Chemistry | 2002
Gaëlle Trippé; Maitena Ocafrain; Mohamed Besbes; Vincent Monroche; Joël Lyskawa; Franck Le Derf; Marc Sallé; Jan Becher; Barbara Colonna; Luis Echegoyen
A straightforward synthesis of new thiol derivatives incorporating the tetrathiafulvalene (TTF) moiety is presented. These electroactive systems form highly stable self-assembled monolayers (SAMs) on gold electrodes. The electrode obtained by SAM formation from a thiol derivative whose structure associates the redox-active TTF unit and a crown-ether ligating part, allows the voltammetric recognition of barium.
Advanced Materials | 2013
Truong Khoa Tran; Kacem Smaali; Marie Hardouin; Quentin Bricaud; Maitena Ocafrain; Philippe Blanchard; Stéphane Lenfant; Sylvie Godey; Jean Roncali; Dominique Vuillaume
A crown-ether dithiol quaterthiophene is synthesized and immobilized on gold surface by double covalent fixation. UV-vis spectroscopy and cyclic voltammetry show that the corresponding dithioester precursor can complex Pb(2+) in solution and that this property is maintained for monolayers of the dithiol on gold. Current-voltage measurements by eutectic GaIn drop contact on the monolayer show a significant increase (up to 1.6 × 10(3) times) of the current at low bias after Pb(2+) complexation.
Chemistry: A European Journal | 2008
Truong Khoa Tran; Maitena Ocafrain; Sandrine Karpe; Philippe Blanchard; Jean Roncali; Stéphane Lenfant; Sylvie Godey; Dominique Vuillaume
Quaterthiophenes bearing one (1) or two (2) alkanethiol chains attached at the internal beta-position of the outermost thiophene ring through a sulfide linkage have been synthesized. Cyclic voltammetric analysis of their electrochemical behavior in solution suggests that electrooxidation of the doubly substituted oligomer 2 leads to electrodeposition of a poly(disulfide) on the anode surface. Monolayers of 1 or 2 on gold surfaces have been investigated and characterized by cyclic voltammetry, ellipsometry, contact angle measurement, and X-ray photoelectron spectroscopy. The results of these investigations indicate that introduction of two thiol groups in the structure leads to double fixation of the oligothiophene chain with the main axis of the conjugated system oriented parallel to the surface. The effects of single versus double fixation of the quaterthiophene chain on the electrochemical properties and stability of the corresponding monolayers are discussed.
Chemistry: A European Journal | 2011
Truong Khoa Tran; Quentin Bricaud; Maitena Ocafrain; Philippe Blanchard; Jean Roncali; Stéphane Lenfant; Sylvie Godey; Dominique Vuillaume; David Rondeau
The synthesis and characterization of a series of quaterthiophenes (4Ts) with thiolate groups protected with 2-cyanoethyl (CNE), 2-trimethylsilylethyl (TMSE), and acetyl (Ac) groups are described. Sequential cleavage of these different protecting groups allows for the preparation of 4Ts derivatized with ferrocene and/or alkanethiol chains. The electrochemical behavior of these compounds has been analyzed in solution by cyclic voltammetry (CV). A ferrocene-derivatized dithiol 4T 14 and a dithiol 4T 15 with two TMSE-protected thiolate groups have been immobilized on a gold surface as monolayers that have been characterized by CV, ellipsometry, contact-angle measurement, and X-ray photoelectron spectroscopy (XPS). The results show that molecules 14 and 15 are doubly grafted with a horizontal orientation of the conjugated system relative to the surface. Furthermore, application of the deprotection/alkylation sequence of the remaining protected thiolate groups on a monolayer of 15 allows for efficient post-functionalization.
Advanced Functional Materials | 2008
Maitena Ocafrain; Truong Khoa Tran; Philippe Blanchard; Stéphane Lenfant; S. Godey; Dominique Vuillaume; Jean Roncali
Chemistry: A European Journal | 2003
Maitena Ocafrain; M. Ángeles Herranz; Lucien Marx; Carlo Thilgen; François Diederich; Luis Echegoyen
ChemElectroChem | 2014
Ali Yassin; Maitena Ocafrain; Philippe Blanchard; Romain Mallet; Jean Roncali
Journal of Physical Chemistry C | 2017
S. Lenfant; Y Viero; C Krzeminski; Dominique Vuillaume; Dora Demeter; I Dobra; Maitena Ocafrain; Philippe Blanchard; Jean Roncali; C. Van Dyck; Jérôme Cornil