Synthesis of cyclopentadienyl ruthenium complexes containing 5-membered N-heterocyclic thiolates

Mononuclear ruthenium–thiolate complexes of structural type CpRu(PPh3)2SR (1) [R = 2-imidazolyl (a), 1-methylimidazolyl (b), 5-methyl-1,3,5-thiadiazolyl (c) and 5-methyl-4H-1,2,4-triazolyl (d)] are accessible from the reaction of CpRu(PPh3)2Cl with the corresponding thiolate anions. Reaction of CpRu(PPh3)2Cl with the heterocyclic-thiolate anions in the presence of the bisphosphine ligands affords CpRu(P–P)SR [P–P = bis(diphenylphosphino)methane; dppm (2), bis(diphenylphosphino)ethane; dppe (3)]. If CO gas was bubbled through a THF solution of 1b, the complex CpRu(PPh3)(CO)S(C4N2H5) (4b) is produced. These ruthenium–heterocyclic thiolate complexes have been characterized by elemental analysis, spectroscopy (IR, 1H, 31P{1H} NMR and MS) and cyclic voltammetry for some samples. The solid-state structures of 3a and 3b are determined by single-crystal X-ray structure analysis.