Preparation, structure and properties of compounds containing the dipositive tri‐copper hexa(<i>N,N</i>‐di‐<i>n</i>‐butyldithiocarbamato) ion, compounds with copper in the oxidation states II and III

Abstract

Abstract The preparation, some magnetic, spectral and electrochemical properties of the compounds [Cu 3 (Bu 2 dtc) 6 ] [MBr 3 ] 2 (M = Zn, Cd, Hg) are reported. The crystal structure of the compound [Cu 3 (Bu 2 dtc) 6 ] [CdBr 3 ] 2 has been determined by a three‐dimensional X‐ray analysis. The triclinic cell, space group magnified image with a = 12.629(4), b = 13.706(4), c = 12.506(4) Å and α = 95.84(4). β = 91.45(4), γ = 86.06(3)°, contains one formula unit. Atomic parameters were refined to a conventional R value of 0.05 for 1344 independent non‐zero reflections. The structure consists of two centrosymmetric ionic units [Cu 3 (Bu 2 dtc) 6 ] 2+ and [Cd 2 Br 6 ] 2− . In the cation one copper atom has an apically distorted octahedral S‐coordination, with CuS distances of 2.30(1), 2.35(1) and 3.19(1) Å. The two other equivalent copper atoms have five‐fold pyramidal S‐coordinations with CuS distances of 2.21(1), 2.22(1), 2.23(1), 2.23(1) and 2.88(1) Å. The Cd 2 Br ion can be described as a slightly‐distorted edge‐condensed bitetrahedron. Esr single‐crystal spectra prove localisation of the unpaired electron at one copper atom. The I.R. spectra show double CuS and CN stretching frequencies. All these data suggest the compounds to be composed of copper in different states of oxidation. The cation can be described as [(Cu(III)(Bu 2 dtc) 2 ) 2 Cu(II)(Bu 2 dtc) 2 ] 2+ . The ionic structure is confirmed by conductivity measurements.