Diolefin and carbonyl rhodium(I) and iridium(I) complexes with phosphine sulphide ligands. Crystal structure of [Rh(COD)(Et 2P(S)(S)PEt 2)]ClO 4

Abstract

The preparation and properties of new diolefinic or carbonyl cationic rhodium and iridium complexes with phosphine sulphide ligands of the type [M(COD)L 2] n n+ or [M(CO) 2L 2] n n+ ( n = 1 or 2) (L = Me 3PS, Et 3PS and Ph 3PS, L 2 = Me 2P(S)(S)PMe 2, Et 2P(S)(S)PEt 2 and Ph 2P(S)(S)PPh 2) are described. The complexes have been characterized by elemental analyses, IR spectra, conductance studies and 31P NMR spectroscopy. Oxidative addition of I 2 gives Ir III complexes. Diolefinic complexes with phosphine sulphide are catalyst precursors in the homogeneous hydrogenation of olefins. The crystal structure of [Rh(COD)(Et 2P(S)(S)PEt 2)]ClO 4 has been determined by X-ray diffraction methods. The crystals are monoclinic, space group P2 1/ c, with a 12.754(1), b 13.333(1), c 13.637(1) Å, β 95.30(1)°, Z = 4. The cationic complex [Rh(COD)(Et 2P(S)(S)PEt 2)] + is monomeric, with the Rh atom showing a slightly distorted square-planar environment. The cyclooctadiene ligand is coordinated to the metal through its two olefinic bonds, and a bis(diethylphosphine) disulphide group, bonded through its two S atoms, acts as a bidentate chelating ligand.