Octahedral and trigonal-bipyramidal complexes of ruthenium(II) with bidentate phosphine ligands
Abstract
Six- and five-co-ordinate complexes of ruthenium(II) with the unsymmetrical diphosphine ligand Ph2P(CH2)3PMe2 have been prepared. Phosphorus-31 n.m.r. spectroscopy indicates that octahedral complexes [RuCl2(P–P)2], [RuH(Cl)(P–P)2], and [RuH(CO)(P–P)2]ClO4(P–P = diphosphine ligand) have the all-trans arrangement with Me2P trans to Me2P and Ph2P trans to Ph2P. The five-co-ordinate complexes [Rux(P–P)2]BPh4, where X = Cl or H, are not fluxional at room temperature and have a trigonal-bipyramidal structure with axial PMe2 groups and equatorial PPh2 groups. Similar structures are proposed for analogous complexes of Ph2P(CH2)3PMePh and of Ph2P(CH2)3PPh2.