Synthesis, characterization and structures of cadmium(II) and mercury(II) complexes with bis(dipiperidinylphosphino)methylamine dichalcogenides

Abstract

Two new bidentate phosphine dichalcogenide ligands of the type MeN(Pip2PE)2 [(Pip = piperidinyl; E = S ( 1 ) or Se ( 2 )] and their cadmium(II) and mercury(II) chloride complexes MCl2{MeN(Pip2PE)2} [M = Cd; E = S ( 3 ); Se ( 4 ) or M = Hg; L = S ( 5 ); Se ( 6 )] were prepared and characterized by elemental analysis, IR, multinuclear (31P, 77Se and 113Cd) NMR spectroscopy and single crystal X-ray analyses. Ligands 1 and 2 were found to adopt anti conformation structures in the solid state in which both P=E groups are trans to each other. Complexes 3 - 6 are comprised of one ligand coordinated in a bidentate fashion to the metal centre in a distorted tetrahedral arrangement [98.46(3)-121.24(4)°]. The P=S bond lengths of 1.999(15)-2.003(14) Å in the complex ( 3 ) are slightly elongated compared to those in free ligand [1.933(15)-1.950(14) Å]. The results are discussed and compared with closely related analogues.