Infrared spectra and density functional theory calculations of coinage metal disulfide molecules and complexes.

Sulfur diatomic molecules were reacted with laser ablated Cu, Ag, and Au atoms in excess argon and condensed at 7 K. Several reaction products were identified for each metal from matrix infrared spectra through sulfur-34 isotopic shifts, spectra of sulfur isotopic mixtures, and frequencies calculated by density functional theory. The linear centrosymmetric (63)CuS(2), (65)CuS(2), and AuS(2) metal disulfide molecules were observed at 508.7, 504.8, and 455.9 cm(-1), respectively. The bent CuSS, AgSS, and AuSS isomers were identified from 608.6, 580.7, and 601.1 cm(-1) S-S stretching fundamentals, respectively. These group 11 metals also formed cyclic tetrasulfur molecules, MS(4), in contrast to group 10 metal atoms, which formed side-bonded disulfur complexes M(S(2))(2).