Alkyne Addition to a Metal-Stabilized Thiyl Radical: Carbon–Sulfur Bond Formation between 1-Octyne and [Ru(SP)3]+



The metal-stabilized thiyl radical complex [Ru(SP)3]+, [Ru-1]+, {SP = 2-(diphenylphosphanyl)benzenethiolate} adds 1-octyne across the cis-sulfur sites to yield the S-alkylated dithiolene product [Ru-octyne]+. The product complex exists as a pair of inseparable geometric isomers, which were characterized by X-ray crystallography, 31P NMR spectroscopy, and cyclic voltammetry. By using electrochemical methods, the rate constant for 1-octyne addition was determined as 8.7 × 103M–1 s–1.