Photophysical Properties and Electropolymerization of Gold Complexes of 3,3′′-Diethynyl-2,2′:5′,2′′-terthiophene

The preparation and crystal structures of 3,3′′-diethynyl-2,2′:5′,2′′-terthiophene (A2T3) and three Au(I) complexes containing this ligand are reported. One of the complexes, Au2(dppm)(A2T3), has a short Au−Au distance (3.1969 Å) because of an aurophilic interaction. UV/vis absorption and emission spectra of the complexes and ligand at 298 and 85 K and photoinduced electron transfer to methyl viologen are reported. A2T3 and two of the complexes may be electropolymerized, and the resulting gold-containing films were characterized by X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry.