Preparation and variable-temperature nuclear magnetic resonance studies of tris(diphenyltrifluoromethylphosphine)platinum(0)

Abstract

The preparation of tris(diphenyltrifluoromethylphosphine)platinum(O) is described. show that the rapid phosphine exchange occurring at room temperature is frozen out at ca. -50" and that at lower temperatures a further dynamic process, possibly associated with rotation of phosphine about the Pt-P bond, is reduced in rate, Similar studies of dichloromethane solutions of the title compound in the presence of different excesses of free phosphine show the formation of the tetrakis complex and of a new previously unobserved species. The possible nature of this new species is discussed. IntroductionA large number of zerovalent platinum compounds are now known, many of which contain a tertiary phosphine as the stabilizing ligand. Aryl-,l-3 alkyl-,4 arylalkyl-,5,6 alkylperfluoroaryl-,5,6 and fluorophosphines7 have been used for this purpose. Tri-and tetracoordinate species have long been known as stable solids, although in certain cases5.8 dissociation of the tetrakis complex occurs in solution to the tris complex and free phosphine. Moreover, rapid phosphine-exchange processes have been observed in solution for a number of the complexes. Dissociation of the tetrakis to the tris complexes has been observed only for the triaryl-and alkyldiarylphosphine