Synthesis and spectroscopy of cis-configured mononuclear palladium(II) and platinum(II) complexes of chalcogeno o-carboranes and structures of [Pt(SCboPh)2(dppm)], [Pt(SeCboPh)2(dppm)], [Pt(SCboS)(PMe2Ph)2] and [Pt(SCboS)(PMePh2)2]

The reactions of [MCl2(P∩P)] and [MCl2(PR3)2)] with 1-mercapto-2-phenyl-o-carborane/NaSeCboPh and 1,2-dimercapto-o-carborane yield mononuclear complexes of composition, [M(SCboPh)2(P∩P)], [M(SeCboPh)2(P∩P)] (M = Pd or Pt; P∩P = dppm (bis(diphenylphosphino)methane), dppe (1,2-bis(diphenylphosphino)ethane) or dppp (1,3-bis(diphenylphosphino)propane)) and [M(SCboS)(PR3)2] (2PR3 = dppm, dppe, 2PEt3, 2PMe2Ph, 2PMePh2 or 2PPh3). These complexes have been characterized by elemental analysis and NMR (1H, 31P, 77Se and 195Pt) spectroscopy. The 1J(Pt–P) values and 195Pt NMR chemical shifts are influenced by the nature of phosphine as well as thiolate ligand. Molecular structures of [Pt(SCboPh)2(dppm)], [Pt(SeCboPh)2(dppm)], [Pt(SCboS)(PMe2Ph)2] and [Pt(SCboS)(PMePh2)2] have been established by single crystal X-ray structural analyses. The platinum atom in all these complexes acquires a distorted square planar configuration defined by two cis-bound phosphine ligands and two chalcogenolate groups. The carborane rings are mutually anti in [Pt(SCboPh)2(dppm)] and [Pt(SeCboPh)2(dppm)].