Dominique Lorcy

A benzenetetrathiolate-bridged dinuclear platinum(diimine)(dithiolene) complex exhibits unprecedented deep near-infrared luminescence (1172 nm) upon two-electron oxidation.

Oxidation of a bis(selenomethyl)-substituted TTF with TCNQF ₂ activates Se⋯N chalcogen bonding, when compared with the neutral TCNQMe ₂ charge-transfer complex.

We report here our investigations to evaluate the potential use of conductive 2 : 1 (TMTTF) ₂ X radical salts (TMTTF = tetramethyltetrathiafulvalene; X = PF ₆ ⁻ , ClO ₄ ⁻ , BF ₄ ⁻ , AsF ₆ ⁻ ) as positive organic electrode materials for energy storage applications.

A diverse library of π-conjugated electron acceptors is essential for the rational design of molecular materials with tunable electronic properties. In this context, the development of structurally related acceptors, including 3,3'-dialkyl-5,5'-bithiazolidinylidene-2,2'-dione-4,4'-dithiones (OS-R), their isomers 3,3'-dialkyl-5,5'-bithiazolidinylidene-4,4'-dione-2,2'-dithiones (SO-R), and their sulfur analogues 3,3'-dialkyl-5,5'-bithiazolidinylidene-2,4,2',4'-tetrathiones (SS-R), with adjustable redox properties remains a key objective. In the present study, we focus on the intrinsic reactivity of these acceptor cores to deliberately tune their redox behavior. The resulting compounds were structurally characterized. Moreover, iodine atoms were incorporated into the acceptor framework to induce halogen bonding interactions, which were confirmed by X-ray diffraction analyses in both the synthetic precursors and the corresponding acceptors.

Based on a step-by-step procedure, an extensive series of monoanionic d8 gold complexes has been developed by replacing in mixed-ligand bis(dithiolene) complexes the coordinating sulfur atoms by selenium ones, either on one ligand or on both, leading to very original and stable mixed-ligand gold (dithiolene)(diselenolene) and bis(diselenolene) complexes. The neutral radical species obtained upon 1e– oxidation of bis(dithiolene) gold complexes are known to exhibit an NIR absorption band in the 1180−2070 nm range, of interest in telecommunications, biological imaging and solar cells. Here, spectroelectrochemical investigations demonstrate that the NIR signature of mixed-ligand bis(dithiolene), (dithiolene)(diselenolene) and bis(diselenolene) gold complexes associating two different dithiolene or diselenolene ligands is found at higher energy, out of the range of the homoleptic analogs. Moreover, introduction of Se atoms on the more electron-rich ligand modifies significantly the LUMO of the complex, leading to a further 200 nm bathochromic shift of this characteristic NIR absorption, thus offering an additional control of the NIR absorption of these neutral radical gold complexes.

Three mixed-ligand gold bis(dithiolene) complexes involving one TTF dithiolate show a robust gap under pressure due to the reinforced dimerization of TTF dithiolate moieties in the solid state.

Despite its non-planar structure, a neutral gold bis(dithiolene) radical complex organized into uniform, non-dimerized stacks, exhibiting metallic conductivity under pressure.

Multinuclear complexes involving two or three redox active Pt(dithiolene) moieties were synthesized and electronic interactions were analysed through a combination of experimental and theoretical investigations.

Two series of gold(iii) bis(dithiolene) complex-based therapeutic agents displaying both anticancer and antiplasmodial activities have been synthesized and characterized.