Exploring radical gold bis(dithiolene) complexes as NIR-II absorbers – NIR-ABS

Within this NIR-ABS project, we aim at developing an extended library of coordination complexes with a strong absorption in the NIR-II region as an emerging class of attractive molecules with interesting photothermal properties. Near Infra-Red (NIR) light spanning from 780 to 2500 nm carries important information for multiple applications in telecommunications, for biological imaging or solar cells. Most of the molecular compounds developed so far for these numerous applications absorb in the NIR-I region, between 650 and 1000 nm, as for example neutral nickel bis(dithiolene) complexes. For many applications however, absorption in the NIR-II region (1000-1700 nm) would be highly desirable. We want to develop here a library of radical gold complexes absorbing in the desired 1000-1700 nm NIR-II range and exhibiting a photothermal effect, to be investigated also in the solid state for their photothermoelectric properties. For that purpose, we will particularly explore novel synthetic tools to generate original, mixed-ligand radical gold dithiolene complexes, offering an invaluable diversity of solution and solid-state properties in the NIR-II range. This PRME project is based on the combined efforts of nine members of the MaCSE team (Condensed Matter and Electroactive Systems) at Institut des Sciences Chimiques de Rennes, gathering together their expertise in organic (hetero)chemistry (S, Se) and coordination chemistry of dithiolene complexes, in photothermal properties in the NIR, and in structural and electronic properties of single-component conductors.