Perfluoroalkylphosphine coordination chemistry of platinum: synthesis of (C2F5)2PPh and (C2F5)PPh2 complexes of platinum(ii)

Abstract

A 1 ∶ 1 addition of Ph₂PCl to an ethereal solution of C₂F₅Li (formed from the reaction of BuLi with C₂F₅Cl) yields Ph₂P(C₂F₅) (abbreviated pfepp) (1). The introduction of a fluoroethyl group results in a phosphine with electronic characteristics that approximate phosphites, bridging the electronic gap between traditional donor phosphine ligands and more electrophilic phosphine ligands like PhP(C₂F₅)₂ (2). The pfepp ligand 1 is isolated as a high boiling liquid, which crystallizes upon standing at room temperature in an inert atmosphere. A series of Pt(II) complexes of the type trans-L₂PtCl₂ (L = pfepp 3; PhP(C₂F₅)₂4) have been prepared and structurally characterized by multinuclear NMR, IR and X-ray crystallography. The crystal structure of 1 is the first example of a structurally characterized monodentate phosphine with a pentafluoroethyl pendant group.