Palladium(ii) complexes with chiral organoantimony(iii) ligands. Solution behaviour and solid state structures

Abstract

The chiral compound (2-Me₂NCH₂C₆H₄)PhSbCl (1) was obtained from (2-Me₂NCH₂C₆H₄)Li and PhSbCl₂ in 1 : 1 molar ratio, while (2-Me₂NCH₂C₆H₄)Mes₂Sb (2) was prepared from (2-Me₂NCH₂C₆H₄)SbCl₂ and MesMgBr in 1 : 2 molar ratio. The compounds 1 and 2 were used to obtain the Pd(II)/stibine complexes: [Me₂NHCH₂C₆H₅]⁺[PdCl₃{SbCl(Ph)(C₆H₄CH₂NMe₂-2)-Sb}]⁻ (3) and [PdCl₂{SbMes₂(C₆H₄CH₂NMe₂-2)-N,Sb}] (4). All the compounds were characterized by multinuclear NMR spectroscopy in solution, elemental analysis, mass spectrometry and single-crystal X-ray diffraction studies. In compounds 1–3 the coordination geometry around the antimony atom is pseudo-trigonal bipyramidal, while in compound 4 a tetrahedral geometry around the antimony atom is observed. Theoretical calculations at the DFT level on compounds 1–4 were used in order to gain insight into the nature of the coordinative bonds.