Syntheses, properties, crystal and molecular structure of a novel neutral pentanuclear copper(I) iodide species. Copper(I) complexes with tetraethylthiuram monosulfide

The reaction of copper(I) iodide with tetraethylthiuram monosulfide L^Et afforded the novel copper(I) pentanuclear neutral complex [CU₅L^Et₂I₅]·EtOH·MeCN 1. Its crystal structure may be described as a very distorted octahedral central Cu₃I₃ cage having two additional CuL^Et(I) units fused to the central cage by means of two iodine and one sulfur bridging atom. All copper(I) atoms in 1 are tetrahedral and both sulfur ligands are bidentate. The solvent molecules occupy intermolecular vacancies generated by the manner in which 1 is packed in space. In contrast, other copper(I) halides CuX (X = Cl or Br) with tetraethylthiuram monosulfide afforded the copper(I) complexes [CuL^Et(X)] (X = Cl 2 or Br 3) which exist in the solid state as monomeric units featuring three-co-ordinate copper(I). The ligands are bidentate and co-ordination is completed by the halogen atoms. The complexes were additionally characterized by IR and ¹H NMR spectra as well as magnetic susceptibility measurements. Complexes 2 and 3 can be alternatively prepared by sulfur abstraction from the disulfides, using triphenylphosphine. Copper(I) iodide and tetraethylthiuram monosulfide failed to yield a mononuclear compound under a variety of experimental conditions.