Synthesis and characterisation of [Pt2(μ-S)(μ-I)(PPh3)4]+ – A cationic iodo analogue of the metalloligand [Pt2(μ-S)2(PPh3)4]

Reaction of [Pt2(μ-S)2(PPh3)4] with a number of transition metal–iodo complexes leads to the formation of the cationic iodo analogue [Pt2(μ-S)(μ-I)(PPh3)4]+, identified using electrospray ionisation mass spectrometry (ESI MS). Synthetic routes to this complex were developed, using the reaction of [Pt2(μ-S)2(PPh3)4] with either [PtI2(PPh3)2] or elemental iodine. The complex was characterised by NMR spectroscopy, ESI MS and an X-ray structure determination, which reveals the presence of a planar, disordered {Pt2SI}+ core. Monitoring the iodine reaction by ESI MS allows the identification of various iodine species, including the short-lived intermediate [Pt2(μ-S)2(PPh3)4I]+, which allows a mechanism for the reaction to be proposed.

Graphical abstractThe novel diplatinum complex [Pt2(μ-S)(μ-I)(PPh3)4]+ is formed in reactions of [Pt2(μ-S)2(PPh3)4] with metal–iodo complexes, and was synthesised by reaction with either cis-[PtI2(PPh3)2] under reflux, or with elemental iodine at room temperature. The synthesis, stability and chemical properties of this system have been probed using electrospray ionisation mass spectrometry. An X-ray structure determination on the hexafluorophosphate salt reveals a planar {Pt2SI} core.Figure optionsDownload full-size imageDownload as PowerPoint slide