Reactions of copper(II) with [S2P(OR)2]–(R = Et or Pri) and single-crystal X-ray studies of Cu[S2P(OEt)2]·bipy and Cu[S2P(OEt)2]·2PPh3

Abstract

The position of the equilibrium (i)(R = Et or Prⁱ) has been shown to be solvent dependent. 2Cu[S₂P(OR)₂]₂ 2Cu[S₂P(OR)₂]+[(RO)₂P(S)S–]₂(i) The addition of nitrogen bases or triphenylphosphine affects the position of the equilibrium; for instance aromatic bases and PPh₃ favour the formation of copper(I) adducts. The structures of two such adducts, Cu[S₂P(OEt)₂]·bipy (1)(bipy = 2,2′-bipyridyl) and Cu[S₂P(OEt)₂]·2PPh₃(2), have been determined by X-ray methods. Complex (1) is triclinic, space group P, with a= 9.388(6), b= 10.208(7), c= 10.704(7)Å, α= 95.88(5), β= 68.44(5), γ= 115.94(6)°, and Z= 2. 2 190 Independent reflections above background were measured and the structure refined to R 0.080. Complex (2) is monoclinic, space group P2₁/n, with a= 11.88(1), b= 14.70(1), c= 22.09(1)Å, β= 91.0(1)°, and Z= 4. 4 087 Independent reflections above background were measured and the structure refined to R= 0.056. Complex (1) exists as a centrosymmetric dimer with a [graphic omitted] chair-shaped ring in which two S₂P(OEt)₂ groups bridge two four-co-ordinate metal atoms. The co-ordination spheres of the metal atoms consist of two sulphur atoms [Cu–S(1) 2.347(3), Cu–S(2) 2.323(4)Å] and two nitrogen atoms from chelating bipy groups [Cu–N(1) 2.059(10), Cu–N(2) 2.132(8)Å], making up a distorted tetrahedral environment. Complex (2) is monomeric, with the metal atom bound to two PPh₃ molecules [Cu–P(1) 2.282(2), Cu–P(2) 2.264(2)Å] and a [S₂P(OEt)₂]^– ion [Cu–S(1) 2.453(2), Cu–S(2) 2.440(2)Å] to give an approximately tetrahedral co-ordination sphere.