Emilie Ripaud

Polarizability and internal charge transfer in thiophene-triphenylamine hybrid π-conjugated systems.

Extended star-shaped conjugated systems consisting of dicyanovinyl electron-acceptor units connected to a triphenylamine core by means of thiophene (T), thienylenevinylene (TV), and bithiophene (BT) conjugating spacers have been synthesized. The analysis of the electronic properties of the molecules by UV-vis absorption spectroscopy, cyclic voltammetry, and theoretical calculations shows that the electronic properties of the systems depend on the length and rigidity of the conjugating spacer.

Contribution from a hole-conducting dye to the photocurrent in solid-state dye-sensitized solar cells.

The hole transporting medium in solid-state dye-sensitized solar cells can be utilized to harvest sunlight. Herein we demonstrate that a triphenylamine-based dye, used as hole-transporting medium, contributes to the photocurrent in a squaraine-sensitized solid-state dye-sensitized solar cell. Steady-state photoluminescence measurements have been used to distinguish between electron transfer and energy transfer processes leading to energy conversion upon light absorption in the hole-transporting dye.

Electropolymerization of triphenylamine–dithiafulvene hybrid extended pi-conjugated systems

Extended hybrid conjugated systems based on a triphenylamine core with 1, 2 and 3 peripheral dithiafulvenyl units have been studied by cyclic voltammetry and UV-Vis absorption spectroscopy. The substitution pattern of the triphenylamine core determines two different electrochemical coupling mechanisms leading to two types of electrogenerated extended conjugated electroactive systems. The structure and properties of polymeric species are also presented.

Terpyridine–tetrathiafulvalene hybrid ligands and their electroactive metal complexes

The synthesis and full characterization (including X-ray structures) of two redox-active terpyridine–tetrathiafulvalene ligands namely (4′-amido-2,2′:6′,2′′-terpyridyl)-6,7-ethylenedithiotetrathiafulvalene (1) and 2-(4′-thioacetamide-2,2′:6′,2′′-terpyridyl)-3,6,7-tris(methylsulfanyl)-6,tetrathiafulvalene (2) are described. The binding properties of these multifunctional systems for various transition metal cations (Ni2+, Zn2+, Cd2+ and Fe2+) are analyzed in solution by cyclic voltammetry and UV-visible spectroscopy. In addition, a tetrahedral neutral zinc metal complex of ligand (2) formulated as (MeS)3-TTF-SCH2CONH-Tpy-ZnCl2·MeOH [complex (3)] and an octahedral nickel complex formulated as [{(MeS)3-TTF-SCH2CONH-Tpy}2Ni]·(ClO4)2·0.5(H2O) [complex (4)] are characterized in the solid state by X-ray diffraction.

Polymorphism of lead(II) benzenethiolate: a noncentrosymmetric new allotropic form of Pb(SPh)2

Depending upon its conditions of crystallization, lead(II) benzenethiolate can exist in two forms: a low-temperature centrosymmetric phase α-Pb(SPh)2 which can be converted by heating into the noncentrosymmetric, 2nd order NLO strongly active and room temperature metastable β-Pb(SPh)2 phase, thus affording an example of transition towards noncentrosymmetry induced by a rise of temperature.