Synthesis, crystal structure, photophysical properties and theoretical studies of [Cu 3(Ph 2PCH 2PPh 2) 3(WS 4)]ClO 4

Abstract

The reaction of [Cu 2(dppm) 2(MeCN) 4] 2+ [dppm = bis(diphenylphosphino)methane] with [WS 4] 2- gives the cationic d 0-d 10 complex [Cu 3(dppm) 3(WS 4)] +, the crystal structure of which has been determined. The three copper atoms and the thiotungstate ligand form a distorted 'flywheel' array with W ⋯ Cu separations of 2.790(3), 2.803(3) and 2.834(3) Å. In the solid state the complex shows an intense emission with λ max at 615 nm. Extended-Hückel molecular-orbital calculations reveal that the emitting state may arise from a [ψ(Cu,P) → W VI] charge-transfer transition.