Platinum(II) tetramesityltetraphosphane-1,4-diides

Abstract

[Na₂(thf)₄(P₄Mes₄)] (1) (Mes = 2,4,6-Me₃C₆H₂) reacts with one equivalent of [PtCl₂(cod)] (cod = 1,5-cycloctadiene) or [PtCl₂(dppe)] (dppe = bis(diphenylphosphino)ethane) to give the corresponding platinum(II) tetramesityltetraphosphane-1,4-diide complexes [Pt(P₄Mes₄)(cod)] (2) and [Pt(P₄Mes₄)(dppe)] (3). The Pt–P bonds of these complexes proved to be extraordinarily stable and did not react with insertion reagents such as tert-butyl isocyanide or cyclohexyl isocyanide. Instead, ligand transfer occurred to give [Pt(P₄Mes₄)(CNBu^t)₂] (4) and [Pt(P₄Mes₄)(CNCy)₂] (5). Further reactions of 2–5 with CO, CS₂, white phosphorus, MeI and ethyl diazoacetate led either to formation of cyclo-P₄Mes₄ and cyclo-P₃Mes₃ or to unidentified products, in which no evidence of insertion of these reagents into the Pt–P bond was observed.