Synthesis and photophysical properties of GemPhos noble metal complexes

Abstract

GemPhos, a diphosphine ligand with a rigid paracyclophane scaffold, was used to prepare complexes of the noble metals gold, palladium, and platinum. The reaction of GemPhos with [Au(tht)2][ClO4] (tht = tetrahydrothiophene) surprisingly yielded a mononuclear charge separated gold compound [(GemPhos)Au][ClO4], in which the gold atom exhibits an uncommon trigonal planar coordination geometry. Furthermore, similar palladium [(GemPhos) (PdCl2)] and platinum [(GemPhos)(PtCl2)] complexes were obtained in very good yields by the reaction of GemPhos with [MCl2(COD)] (M = Pd, Pt; COD = 1,5-cyclooctadiene) in hot DMSO. All compounds were fully characterized by analytical and spectroscopic techniques and their solid-state structures were established by single X-ray crystallography. Their photoluminescent properties were measured at low and ambient temperatures, revealing different behavior depending on the metal and coordination mode.