Mononuclear and binuclear Cu(I) complexes with metal-sulfur ligation

Abstract

The synthesis, characterization and electrochemistry of the copper(I)(triphenylphosphine)-chloride, bromide and iodide complexes of pyridine-2-thione (py2SH), pyridine-4-thione (py4SH) and pyrimidine-2-thione (pymtH) and the crystal structure of the complex [Cu(py2SH(PPh 3)Br] 2 are reported. Crystals of [Cu(py2SH)(PPh 3)Br] 2 are triclinic, space group P 1 , with a=9.586(4), b=9.562(5), c=13.573(5) Å, α=77.56(3), β=73.32(3), γ=62.38(3)° and Z=1. The molecule contains a planar Cu 2S 2 moiety with bond lengths Cu(1)S(1)=2.383 Å and Cu(1)S(1′)=2.392 Å and bond angles SCuS=88.5° and CuSCu′=91.5°. The structure has been solved by direct methods with a final R of 0.039. The complex is binuclear, the stereochemistry of the Cu 2S 2 core is strictly planar. The equivalent copper atoms have pseudotetrahedral geometry. The electrochemical study indicates that the potentials are in the fange of about +0.3 to +1.1 V versus SCE. The synthesis and structure determination at 140 K of Cu(py2SH)(PPh 3) 2Br is also reported. Crystals are monoclinic, space group P2 1/ n, with a=9.436(3), b=19.168(5), c=19.597(5) Å, β=91.31(3)° and Z=4. The metal ion has a distorted tetrahedral geometry with bond lengths CuS=2.302, CuBr=2.462 and CuP=2.263–2.267 Å. The structure has been solved by direct methods with a final R of 0.075.