Complexes of osmium with polytertiary phosphines

Abstract

Complexes of Osmium(II) and Osmium(III) with the polytertiary phosphines, C 6H 5P[CH 2CH 2P(C 6H 5) 2] 2; (triphos), (C 6H 5) 2PCH 2CH 2P(C 6H 5)CH 2CH 2P(C 6H 5)CH 2CH 2P(C 6H 5) 2 (tetraphos-1), P[CH 2CH 2P(C 6H 5) 2] 3; (tetraphos-2) and C 6H 5{CH 2P[CH 2CH 2P(C 6H 5) 2] 2} 2; (TDDX) are described. Osmium trichloride reacts with triphos, tetraphos-1, and tetraphos-2 in benzene methanol mixture at reflux temperature to give the complexes OsCl 3 (triphos), [OsCl 3(S)] 2 (tetraphos-1) and OsCl 3(tetraphos-2) respectively. The hexatertiary phosphine TDDX, formed only polynuclear complexes with osmium and attempts to prepare mononuclear complexes failed. The ligand TDDX reacted with either osmium trichloride or ammonium hexachloro osmate(IV) in boiling ethanol to give the diamagnetic trinuclear complex Os 3Cl 6(TDDX) and paramagnetic complexes of the type Os 2X 6(TDDX) where XCl or Br). The proton NMR spectra of the complexes are discussed and used along with the IR data to assign configurations.