Photoredox properties of luminescent trinuclear copper(I) complexes with a bridging phosphine ligand and crystal structure of [Cu3(dpmp)2(MeCN)2(µ-Cl)2]ClO4[dpmp = bis(diphenylphosphinomethyl)phenylphosphine

Abstract

The complexes [Cu3(dpmp)2(MeCN)2(µ-X)2]ClO4 were prepared by the reaction of CuX (X = Cl or I) with bis(diphenylphosphinomethyl)phenylphosphine (dpmp) in methanol followed by recrystallisation from acetonitrile. The complex cation [Cu3(dpmp)2(MeCN)2(µ-Cl)2]+[triclinic, space group P(no. 2), a= 12.839(1), b= 13.582(3), c= 21.510(3)A, α= 84.06(1), β= 72.71(1), γ= 78.00(1)°, Z= 2, R= 0.083 for 11 520 unique Mo-Kα data] consists of three copper(I) ions bridged by two chloride ions on the same side and by two dpmp ligands. The intramolecular, Cu ⋯ Cu separations are 3.26 and 3.30 A indicating no metal–metal interaction. Both [Cu3(dpmp)2(MeCN)2(µ-Cl)2]ClO4 and [Cu3(dpmp)2(MeCN)2(µ-I)2]ClO4 display room-temperature photoluminescence at 530 and 560 nm respectively. The photoredox properties of [Cu3(dpmp)2(MeCN)2(µ-Cl)2]+ have been investigated by flash photolysis and Stern–Volmer quenching experiments.