Bridging and Chelating Roles of Bis(2-(diphenylphosphino)ethyl)phenylphosphine in Stabilizing Binuclear Platinum(II) Complexes

The diorganoplatinum(II) complexes [PtR2(triphos-P,P'] (1; R = Me, p-MeC6H4 and triphos = bis(2-(diphenylphosphino)ethyl)phenylphosphine), containing one free phosphine atom, react with cyclometalated platinum complexes [PtR'((CN)-N-boolean AND)(SMe2)] (2; R' = Me, p-MeC6H4 and (CN)-N-boolean AND is deprotonated 2-phenylpyridine (ppy) or deprotonated benzo[h]quinoline (bhq)) to give the cyclometalated diplatinum(II) complexes [Pt2R2R'((CN)-N-boolean AND)(triphos)] (3). In these binuclear platinum(II) compounds, triphos acts as both a chelating and bridging ligand to stabilize the produced diplatintun complexes. The complexes 3 were readily characterized by multinuclear NMR spectroscopy and elemental microanalysis. The crystal structure of complex 3f (R = Me, R' = p-MeC6H4, and (CN)-N-boolean AND = bhq) was further determined by X-ray crystallography, giving the first example of an X-ray structural determination of a diplatinum complex with a triphos ligand acting simultaneously as both a chelating and bridging ligand.