Synthesis and vibrational spectra of new bis(alkoxysulfane)-dichloropalladium(II) complexes and X-ray structural analysis of [PdCl2{S(OPri)2}2]

Abstract

Reactions of L =(PrⁱO)₂S, (PrⁿO)₂S, (MeO)(C₄H₈NO)S (C₄H₈NO = morpholino), (MeO)(C₅H₁₀N)S (C₅H₁₀N = piperidino) or (MeO)PhS with [PdCl₂(NCPh)₂] in toluene gave five complexes of type [PdCl₂L₂](yields 40–79%). An X-ray structural analysis of the air-stable, monoclinic crystals of [PdCl₂{S(OPrⁱ)₂}₂] showed the sulfur atoms to be cis-planar co-ordinated. The two co-ordinated dialkoxysulfane ligands are rotational isomers with differing SO torsional angles (+79 and 84° for ligand 1, –106 and +82° for 2). The S–O bond lengths are in the range 1.586–1.611 Å. The infrared and Raman spectra of the five [PdCl₂L₂] complexes demonstrate that the rule of mutual exclusion is not obeyed, indicating a cis rather than a trans co-ordination in each case.