Carbon–sulfur bond reductive coupling from a platinum( ii ) thiolate complex

The room temperature addition of electrophilic alkyl halide reagents (RX = MeI, EtI and PhCH 2 Br) to complex [Pt(ppy)( η 1 -S-Spy)(PPh 3 )], 1a , in which ppyH = 2-phenylpyridine and pySH = pyridine-2-thiol, resulted in a rapid carbon–sulfur (C–S) bond reductive coupling to produce alkyl sulfides and corresponding halide complexes [Pt(ppy)(PPh 3 )X], X = I ( 2a ) and Br ( 2b ). A mechanism for this C–S bond formation reaction was suggested based on 1 H and 31 P { 1 H} NMR spectroscopic analyses. In the suggested mechanism, the reaction proceeded through a binuclear intermediate complex [{Pt(ppy)(PPh 3 )} 2 ( μ 2 -Spy)]I, 3-I , which was separately synthesized by another counter anion (PF 6 ) and it was fully characterized by multinuclear NMR spectroscopy and single X-ray crystallography. Also, density functional theory (DFT) calculations were used to theoretically assess the structures of intermediates and transition states in this bond formation reaction.