Theoretical studies on aurophilicity and excited-state properties in binuclear gold (I) trithiocarbonate and related complexes

Abstract

The MP2 and unrestricted MP2 methods were performed to fully optimize the structures of [Au 2(S 2CS) 2] 2− ( 1) in the ground and lowest-energy triplet excited states, respectively. It was shown that upon excitation the Au–Au distance shortens about 0.156 Å with respect to the 2.814 Å one in the ground state. In the calculations, vibrational frequencies at the MP2 level and solution absorption spectra at the TD-DFT level agree with experimental observations. The comparison among 1, [Au 2(S 2CC(CN) 2) 2] 2− ( 2) and [Au 2(S 2CH 2) 2] 2− ( 3) in ground- and excited-state properties was discussed in detail.