First Evidence of Fast SH⋅⋅⋅S Proton Transfer in a Transition Metal Complex

Despite the weakness of SH⋅⋅⋅S interactions and the fact that they have rarely been reported in transition-metal compounds, variable-temperature NMR data and theoretical calculations provide evidence for fast intramolecular proton exchange between the bridging sulfur atoms in the complexes [Pt2{Ph2P(CH2)nPPh2}2(μ-S)(μ-SH)]ClO4 (n=2, 3; see scheme).