Group IB Organometallic Chemistry. XVI. Complex formation between 2-(dimethy- lamino)phenylcopper with copper(I) or silver halides. Synthesis and structural characterization of hexanuclear (2-Me2NC6H4)4Cu6-nMnX2 (M = Cu or Ag) cluster compounds

Abstract

The 21 complexes (2RCu . MX) between 2-(dimethylamino)phenylcopper (RCu) and CuX (X = Cl, Br or I) or AgBr have been prepared in two ways (i) from the 23 reaction of 2-(dimethylamino)phenyllithium with cuprous halide and (ii) from the reaction of RCu with excess of the metalIB halide.The structure of bis[(2-dimethylamino)phenylcopper] cuprous bromide, which is dimeric (R{4}Cu{6}Br{2}) in the solid state, has been determined by X-ray analysis. The bonding in this hexanuclear cluster (Cu@?Cu ranging from 2.48 to 2.70 @9, multicenter bonded aryl groups) is discussed. Molecular weight determinations and }1{H NMR spectroscopy reveal a similar hexanuclear structure for the R{4}Cu{6}X{2} complexes in benzene solution. NMR spectroscopy indicates that in solution the mixed-metal cluster compounds R{4}Cu{6}{-}{n}Ag{n}Br{2} are not stable but enter into interaggregate exchange reactions. A possible pathway involving trinuclear species R{2}Cu{3}{-}{n}Ag{n}X as intermediates is proposed.