The role of halide ligands in copper(I) carbonyl chemistry: synthesis of monohalogen-bridged dinuclear copper(I) carbonyls, and X-ray crystal structure of [Cu2(Me2NCH2CH2NMe2)2(CO)2Cl](BPh4)

Abstract

Reaction of copper(I) halides, CuX (X = Cl, Br, or I), with carbon monoxide in MeOH in the presence of NNN′N′-tetramethylenediamine (tmen) produces dinuclear copper(I) carbonyls, [Cu₂(tmen)₂(CO)₂X]⁺, ν_COca. 2070 cm^–1; the structure of the chloro-derivative, [Cu₂(tmen)₂(CO)₂Cl](BPh₄), has been determined by X-ray crystallography which shows that the two copper atoms in the molecule are bridged by a single halogen atom and the molecule contains a bent Cu–Cl–Cu unit with an angle of 103·0(1)°.