Hydrogen bonding in crystalline alcohol solvates of the platinum(II) sulfido complex [Pt2(μ-S)2(PPh3) 4]

Abstract

Suspension of [Pt2(μ-S)2(PPh3) 4] in lower alcohols results in recrystallisation, forming yellow to yellow-orange microcrystals of the solvates [Pt2(μ-S) 2(PPh3)4]·nROH (R = Me, Et, nBu). The di-ethanol solvate was characterised by means of a single-crystal X-ray diffraction study and 1H NMR spectroscopy. The structure consists of an ethanol molecule hydrogen-bonded in an asymmetric bifurcated fashion to the {Pt2S2} group, with the second, disordered ethanol molecule involved in a cooperative hydrogen-bonding interaction with the oxygen of the first ethanol. Thermogravimetric analysis shows that the alcohol is relatively easily lost, regenerating orange, unsolvated [Pt2(μ-S) 2(PPh3)4]. [Pt2(μ-S) 2(PPh3)4] readily dissolves in hexafluoro-2-propanol, yielding yellow crystals of [Pt2(μ-S) 2(PPh3)4]·6(CF3) 2CHOH on evaporation. Characterisation by X-ray diffraction shows that the structure contains a [Pt2(μ-S)2(PPh 3)4] hydrogen-bonded to a single (CF3) 2CHOH molecule, with the additional (CF3)2CHOH molecules forming a discrete hydrogen-bonded pentameric cluster in the crystal. © Wiley-VCH Verlag GmbH & Co. KGaA, 2008.