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Biomedical subjects

Jean-Claude Moutet

Publications and source records attributed to Jean-Claude Moutet.

8 recordsLinked to original sources
PubMed2006

Redox-active biomolecular architectures and self-assembled monolayers based on a cyclodecapeptide regioselectively addressable functional template.

A nanometer scale redox active biomolecular architecture has been successfully synthesized through an efficient chemoselective oxime based coupling between ferrocenyl groups and a regioselectively addressable cyclodecapeptide. This molecular tool exhibits electronic, structural, and chemical properties driven by the biomimetic recognition activity of the polypeptide skeleton associated to the well-defined electrochemical activity of metallocenyl probes. Biomolecular materials obtained by confinement of the redox cyclopeptide in self-assembled monolayers on gold surfaces shows efficient through-bond electron transfer from the ferrocenes to the electrode surface via the peptidic backbone, as well as markedly improved sensing properties toward anionic species in organic electrolyte, as compared to those observed in homogeneous solution.

Cyclization↗
PubMed2005

Calix[4]phyrin based redox architectures: towards new molecular tools for electrochemical sensing.

New redox active molecular macrocyclic architectures characterized by a direct connection between dipyrrin, tripyrrin and ferrocenyl fragments have been synthesized and characterized. Contrarily to fully conjugated porphyrins, in which four pyrrole moieties contribute to the overall aromatic pi-electronic system and behave as a unique electroactive species, calixphyrins can be regarded as an assembly of independent redox active pyrrole and conjugated oligopyrrole fragments linked through sp(3) hybridized meso carbon atoms. The disruption of the conjugation pathway not only multiplies the number of redox centres throughout the molecule but also leads to a large variety of molecular architectures with specific physico-chemical properties. These novel ferrocene containing hybrid macrocycles exhibit especially attractive electronic and structural features suited for use as molecular sensing tools. An efficient voltammetric sensing of exogenic electron rich anionic species could especially be performed using a metallo-calix[4]phyrin-(1.1.1.1) through the displacement of the labile axial binding site, the perturbation of the Fc(0/+) redox couple being directly related to complexed species features.

Journal Article↗
PubMed2004

Redox-triggered molecular movement in a multicomponent metal complex in solution and in the solid state.

The Cu(I) and Cu(II) complexes of the new 1,8-diferro-cenylmethyl-4,11-dimethyl-1,4,8,11-tetraazacyclotetra-decane ligand (denoted L) have been isolated and characterized by X-ray structure determination and electrochemical studies. The Cu(I) complex presents an unprecedented stability toward dioxygen. The two complexes adopt two energetically distinct and stable geometries, which differ mainly by the relative positioning of the substituents above or below the cyclam plane. Triggered by a copper-centered electron transfer, a fast and reversible motion of the noncoordinating subunits is obtained in homogeneous solution and in the solid state.

Journal Article↗
PubMed2003

Thermically and electrochemically induced isomerization of a (bis(ferrocene)-cyclam)copper(II) complex.

The new bis(ferrocene)-cyclam macrocycle 1,8-bis(ferrocenylmethyl)-1,4,8,11-tetraazacyclotetradecane, denoted L, has been synthesized. Two Cu(II) complexes with L have been isolated and characterized from X-ray structure determination and electrochemical studies. These two LCu(II) complexes correspond to the type I (ferrocenyl subunits in the same side of the cyclam plane) and type III (ferrocenyl subunits above and below the cyclam plane) isomers. The type I LCu(II) complex was synthesized from L and a Cu(2+) salt, while the type III isomer was obtained by oxidation in air or by comproportionation of the Cu(I) complex. The interconversion between type I and type III LCu(II) complexes is negligible in acetonitrile and slow in dimethyl sulfoxide but fast via an electrochemical reduction-reoxidation cycle. According to UV-vis and electrochemical characterizations, the type III isomer is thermodynamically more stable and the type I isomer is kinetically favored. A type III LNi(II) complex was also isolated and characterized by X-ray diffraction analysis and from electrochemical studies.

Journal Article↗
PubMed1996

Synthesis and Characterization of a New Series of Nickel(II) meso-Tetrakis (polyfluorophenyl)porphyrins Functionalized by Pyrrole Groups and Their Electropolymerized Films.

A new series of nickel(II) meso-tetrakis(polyfluorophenyl)porphyrins functionalized by pyrrole groups have been synthesized. Each new complex was isolated and characterized by (1)H NMR, (19)F NMR, IR, UV-visible spectroscopy, and mass spectrometry as well as electrochemistry. This is the first example of polyfluorinated substituted porphyrins where the four possible compounds have been obtained by functionalization of the para-fluorine substituents of the nickel(II) meso-tetrakis(pentafluorophenyl)porphyrin. This functionalization has allowed the preparation for the first time of polyfluorinated metalloporphyrin films by oxidative electropolymerization. Electrochemical stability studies of these polymeric films have shown better stability for films derived from the monomer having four pyrrole groups because of their high degree of cross-linking degree. A large difference of electroactive solute permeation has been found in the polymeric films which have been obtained by electropolymerization of monomers for which one pyrrole group has been substituted compared to those for which four pyrrole groups have been substituted. This could be related to quite rigid polymer structures for tetrasubstituted polymer films and molecular sieving properties of monosubstituted polymer films. The spectroelectrochemistry of a polymeric film on an OTE has established that the two-electron-oxidized species are stable in the film; likewise the singly and doubly electroreduced species are stable and are more likely ligand-centered.

Journal Article↗