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Complexes of the type [XMo(CO) 2 (η 3 -C 3 H 5 )(PP′)] (X  Cl or Br; PP′  R 2 PCH 2 CH 2 PPh 2 ; R = m -FC 6 H 4 ( 1a ), p -FC 6 H 4 ( 1b ), m -CF 3 C 6 H 4 ( 1c )) have been prepared from the reaction of [XMo(CO) 2 (η 3 -C 3 H 5 )(MeCN) 2 ] with the relevant ditertiary phosphines in acetone. From their 1 H NMR and IR data these complexes have been assigned essentially octahedral structures in which the allyl moiety is trans to be unidentate anion, and the two cis -carbonyl groups and two phosphorus donor atoms of the bidentate ligand are approximately coplanar. CO force constants have been calculated.

The ditertiary phosphines, 1-diphenylphosphino-2-bis( m -fluorophenyl) phosphinoethane ( 1a ), 1-diphenylphosphino-2-bis( p -fluorophenyl) phosphinoethane ( 1b ), 1-diphenylphosphino-2-bis( m -trifluoromethylphenyl) phosphinoethane ( 1c ) complexes of ruthenium(II) of the type [Ru(PP′) 2 X 2 ] (X = Cl, Br, I, NCS, PP′ = 1a , 1b or 1c ) and [Ru(CO) 2 (PP′)X 2 ] (X = Cl, Br, I) have been prepared and characterized on the basis of elemental analysis, IR, UV, 1 H NMR and 31 P NMR (in a few cases) data. Based on the result of these studies, trans - and cis -octahedral structures for [Ru(PP′) 2 X 2 ] and [Ru(CO) 2 (PP′)X 2 ] complexes, respectively, have been proposed. In all these cases, the ditertiary phosphines act as potential bidentate chelating ligands.

New complexes of the type [M(CO) 4 (dptpe)] (M = Cr, Mo, W) have been isolated from the reaction of the ligand, 1, 2-bis(di- p -tolylphosphino)ethane (dptpe) with Group VI metal hexacarbonyls in a suitable solvent such as methylcyclohexane. The resulting [M(CO) 4 (dptpe)] complexes on treatment with an excess of pyridine produces the mixed ligand complexes [M(CO) 3 (py)(dptpe)], whereas the reaction of [XMo(CO) 2 (η 3 -allyl)(MeCN 2 )] (X = Cl, Br) with dptpe gives [XMo(CO) 2 (η 3 -allyl)(dptpe)]. The formulation of the structures of these complexes follows from elemental analyses and 1 H NMR, 31 P{ 1 H} NMR and IR spectral studies. Carbonyl force constants have been calculated from the ν(CO) stretching frequencies by the Cotton and Kraihanzel method.

A series of four-coordinate, square-planar, dia- magnetic 1-diphenylphosphino-2-bis(m-trifluoro- methylphenyl)phosphinoethane complexes of type cis-[MX2(m-CF3P-P)] (M = Ni, Pd, Pt; X = Cl, Br, I or NCS) have been prepared. These complexes have been characterized by 31P {1H} NMR, 1H NMR, IR and UV spectroscopy, elemental analyses and magnetic susceptibility measurements. The effects of various substituents on the phenyl groups of the ditertiary phosphines on the solubility characteristics of the metal complexes are discussed.

Complexes of the type [M(CO)4(PP′)] (M = Cr, Mo, W; PP′ = R2PCH2CH2PPh2, R = m-FC6H4(1a), R = p-FC6H4 (1b), R = m-CF3C6H4 (1c)) have been obtained from the reaction of appropriate metal hexacarbonyl with the corresponding ditertiary phosphine in methylcyclohexane/xylene. The order of ease of replacement of carbonyl by these phosphines was found in the sequence of Mo > Cr > W. The complexes [M(CO)4(PP′)] react with excess of pyridine to yield the trisubstituted complexes [M(CO)3(py)(PP′)] (M = Cr, Mo, W; py = pyridine; PP′ = 1a, 1b or 1c). All the complexes have been characterized by elemental analysis and IR and 1H NMR spectroscopy, and are assigned octahedral structures. Carbonyl force constants have been calculated from the (ν)(CO) stretching frequencies. 31P{1H}NMR spectra of [M(CO)4(PP′)] complexes reveal unusually large downfield shifts upon coordination, and these are explained in terms of a ring contribution. The values of the tungsten-phosphorus J(183W-31P) and phosphorusphosphorus J(31P31P′) coupling constants are discussed.

The ditertiary phosphines, 1-diphenylphosphino-2-bis( m -fluorophenyl) phosphinoethane ( 1a ), 1-diphenylphosphino-2-bis( p -fluorophenyl) phosphinoethane ( 1b ), 1-diphenylphosphino-2-bis( m -trifluoromethylphenyl) phosphinoethane ( 1c ) complexes of ruthenium(II) of the type [Ru(PP′) 2 X 2 ] (X = Cl, Br, I, NCS, PP′ = 1a , 1b or 1c ) and [Ru(CO) 2 (PP′)X 2 ] (X = Cl, Br, I) have been prepared and characterized on the basis of elemental analysis, IR, UV, 1 H NMR and 31 P NMR (in a few cases) data. Based on the result of these studies, trans - and cis -octahedral structures for [Ru(PP′) 2 X 2 ] and [Ru(CO) 2 (PP′)X 2 ] complexes, respectively, have been proposed. In all these cases, the ditertiary phosphines act as potential bidentate chelating ligands.