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]ClO 4 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 P1 (no. 2), a = 12.839(1), b = 13.582(3), c = 21.510(3) Å, 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 Å indicating no metal-metal interaction. Both [Cu3(dpmp)2(MeCN)2(μ-Cl) 2]ClO4 and [Cu3(dpmp)2(MeCN)2(μ-I)2]ClO 4 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.