Synthesis and characterization of Group 11 and 12 complexes containing a new thioether-functionalized and pyridine-based bis(phosphine) ligand, 2,6-bis[2-(diphenylphosphino)ethyl-sulfanylmethyl]pyridine

Abstract

The new ligand 2,6-bis[2-(diphenylphosphino)ethylsulfanylmethyl]pyridine, 2,6-(Ph₂PCH₂CH₂SCH₂)₂C₅H₃N (L¹), has been synthesized. Reaction of [Cu(MeCN)₄][CF₃SO₃] or AgNO₃ with 1 molar equivalent of L¹ gave [CuL¹][CF₃SO₃] 1 or [AgL¹][NO₃] 2, in good yield. Reaction of equimolar quantities of L¹ and Au^I, followed by precipitation with AgO₃SCF₃, gave [AuL¹][CF₃SO₃] 3. In the crystal structure of 2·H₂O, L¹ co-ordinates to Ag via a P₂S₂ donor set in a distorted tetrahedral geometry. Reaction of M(O₃SCF₃)₂ (M = Zn or Cd) with 1 molar equivalent of L¹ gave [ML¹(O₃SCF₃)₂] (M = Zn 4 or Cd 5). Crystal structure analysis of 5 showed that the molecule has symmetry 2, with all five donor atoms of L¹ and a pair of monodentate CF₃SO₃^– ligands arranged in an unusual distorted pentagonal bipyramidal co-ordination geometry about the cadmium centre.