Inorganic Chemistry, Vol.46, No.23, 9954-9960, 2007
Coordination of pyridinethiols in gold(I) complexes
High-yield synthesis of gold(l) thionato complexes, bis(pyridine-2-thionato)gold(l) chloride (1) and bis(pyridine-4thionato)gold(l) chloride (2), are described. According to their solid-state structures, a linear coordination of Au(I), equiplanar coordination of the ligands and two weak gamma-agostic interactions are found in both of these complexes despite of different relative positions of IN and S atoms in the pyridinethionato ligands. Density functional theory calculations on 1 and 2 reproduce the observed X-ray structures. Even though the C-H center dot center dot center dot Au interactions of Au(I) and two pyridine moieties (2.83 and 2.88 angstrom in 1 and 2.86 angstrom in 2) are relatively. weak, according to calculations they seem to provide further stabilization for the coordination and orientation of the ligands. In 1 the shortest Au center dot center dot center dot Au distances of 3.50 angstrom indicate that aurophilic interactions, even though weak, are present in the solid state, whereas in 2 these interactions are absent.