A new type of dicopper structure with side arm coordinating triarylphosphane ligands

Abstract

Treatment of P(C 6H 4CH 2NMe 2-2) 3 ( 1) with 2 equiv. of CuX ( 2a X=Cl, 2b X=Br) produces the novel dicopper complexes [P(C 6H 4CH 2NMe 2-2) 3]Cu 2X 2 ( 3a X=Cl, 3b X=Br) in high yields. The X-ray structure of 3b was determined. Crystals of 3b are orthorhombic, space group Pna2 1, with a=19.280(4) Å, b=15.717(3) Å, c=11.201(2) Å, V=3394(1) Å 3, Z=4, and final R 1=0.0573 [ I≥2 σ( I)] for 2301 reflections used (1621 reflection with I≥2 σ( I)) and 340 variables. The structure of 3b consists of two copper(I) centers of which one copper atom possesses a heavily distorted trigonal-pyramidal environment, while the other one is almost square-pyramidal coordinated; the Cu 2Br 2 segment gives rise to a situation, which may be considered as a contact ion pair between Cu + and CuBr 2 − .