Complexes of potentially tri- and tetra-dentate phosphinothiol ligands with Mo, W, Re, Fe, Ru, Os, Rh, Ir and Ni

The phosphinothiolate proligand PPh(C₆H₄SH-2)₂(H₂L²) reacted with a variety of precursors to give the complexes [ML²₂]^n–(M = Mo, W or Re, n= 0; M = Fe, Ru, Os, Rh or Ir, n= 1). The crystal structure of the complex with M = Re revealed a distorted-octahedral geometry with the L² ligands facially co-ordinated. Other precursors gave the complexes [ML²₂X]^n–(X = Cl, M = Re, n= 0; X = NO, M = Mo, n= 1; M = Ru, n= 0; X = NR, M = Re, n= 1; X = NNMePh, M = Mo, n= 0; M = Ru, n= 1). The geometry of these seven-co-ordinate complexes is discussed. The metal(0) complexes [M(CO)₃(MeCN)₃](M = Mo or W) reacted with [NMe₄]₂[L²] to give orange [NMe₄]₂[ML²(CO)₃] the crystal structure of which (M = Mo) showed near-octahedral geometry with facially co-ordinated L². The complex [IrCl(CO)(PPh₃)₂] reacted with H₂L² to give the iridium(III) hydride [IrL²(H)(CO)(PPh₃)]. Its crystal structure showed the expected octahedral geometry with the H atom presumed to be trans to a thiolate sulfur. The potentially tetradentate ligand P(C₆H₄SH-2)₃(H₃L³) reacted with precursors containing Ru, Os and Rh to give [M(HL³)₂]^–(M = Ru, Os or Rh) where each HL³ ligand is ligated via P and 2S with one unco-ordinated thiol group. These complexes were oxidised in air to give [M(L³₂)]ⁿ⁺(M = Ru or Os, n= 0; M = Rh, n= 1) where L³₂ is a hexadentate ligand formed by the coupling of two L³ through two disulfide bonds.