Pressure-Dependent Luminescence Properties of Gold(I) and Silver(I) Dithiocarbamate Compounds

Luminescence spectra for dithiocarbamate complexes of gold(I) and silver(I) display very different luminescence properties. At room temperature, a narrow band with a maximum at approximately 18 000 cm –1 and a broad band with a maximum at approximately 13 000 cm –1 are observed for the gold(I) and silver(I) compounds, respectively. The luminescence from the gold(I) compounds is strongly affected by external pressure, with maxima shifting to lower energy by approximately −120 cm –1 /kbar. In contrast, a silver compound shows a small shift to higher energy by approximately +20 cm –1 /kbar. These shifts are analyzed in terms of structure and bridging ligand geometry, revealing the important influence of unsupported metal–metal interactions on pressure-induced shifts of luminescence bands.