Abstract
Treatment of the dicobalt compound Co2(CO)6(μ-PhC≡CH) (1) with the unsaturated diphosphine ligand (Z)-Ph2PCH=CHPPh2 gives the chelating diphosphine compound Co2(CO)4(μ-PhC≡CH)[(Z)-Ph2PCH=CHPPh2] (2) when the reaction is carried in refluxing 1,2-dichloroethane or in the presence of Me3NO. 2 was characterized in solution by IR and 31P NMR spectroscopy, and the molecular structure of Co2(CO)4(μ-PhC≡CH)[(Z)-Ph2PCH=CHPPh2] was established by X-ray diffraction analysis, which confirmed the chelation of the P-ligand to a single cobalt center. Co2(CO)4(μ-PhC≡CH)[(Z)-Ph2PCH=CHPPh2] crystallizes in the monoclinic space group P21/c, a = 10.151(1), b = 32.694(5), c = 11.051(5) Å, β = 111.14(1)°, V = 3420.7(9) Å3, Z = 4, and d calc = 1.414. The two distinct 31P resonances found in the 31P NMR spectrum of 2 are discussed relative to the X-ray structure and other structurally similar cobalt–alkyne complexes. Thermolysis of Co2(CO)4(μ-PhC≡CH)[(Z)-Ph2PCH=CHPPh2] led only to the slow decomposition of Co2(CO)4(μ-PhC≡CH)[(Z)-Ph2PCH=CHPPh2] and not to the formation of the isomeric bridged-diphosphine complex.
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(a) Bird, P.H.; Fraser, A.R.; Hall, D.N. Inorg. Chem. 1977, 16, 1923. (b) Bianchini, C.; Dapporto, P.; Meli, A. J. Organomet. Chem. 1979, 174, 205. (c) Crow, J.P.; Cullen,W.R. Inorg. Chem. 1971, 10, 2165. (d) Chia, L.S.; Cullen,W.R.; Franklin, M.; Manning, A.R. Inorg. Chem. 1975, 14, 2521. (e) Sappa, E.; Predieri, G.; Marko, L. Inorg. Chim. Acta 1995, 228, 147.
(a) McAdam, C.J.; Duffy, N.W.; Robinson, B.H.; Simpson, J. Organometallics 1996, 15, 3935. (b) Haley, M.M.; Langsdorf, B.L. J. Chem. Soc. Chem. Commun. 1997, 1121.
(a) Yang, K.; Bott, S.G.; Richmond, M.G. Organometallics 1994, 13, 3767; 1995, 14, 4977. (b) Yang, K.; Bott, S.G.; Richmond, M.G. J. Organomet. Chem. 1996, 516, 65.
See also: Yang, K.; Bott, S.G.; Richmond, M.G. Organometallics 1994, 13, 3788.
Greenfield, H.; Sternberg, H.W.; Friedel, R.A.; Wotiz, J.H.; Markby, R.; Wender, I. J. Am. Chem. Soc. 1956, 78, 120.
Shriver, D.F. The Manipulation of Air-Sensitive Compounds, McGraw-Hill: New York, 1969.
(a) Garrou, P.E. Chem. Rev. 1981, 81, 229. (b) Churchill, M.R.; Lashewycz, R.A.; Shapley, J.R.; Richter, S.I. Inorg. Chem. 1980, 19, 1277.
For the original description the two types of CO sites in Co2(CO)6(μ-RC≡CR′) as pseudoaxial and pseudoequatorial, see: Thorn, D.L.; Hoffmann, R. Inorg. Chem. 1978, 17, 126.
(a) Mass, G.; Rahm, R.; Mayer, D.; Baumann, W. Organometallics 1995, 14, 1061. (b) Fronczek, F.R.; Erickson, M.S. J. Chem. Crystallogr. 1995, 25, 737.
The bite angle was calculated by the equation:P—M—P=2arc-sin (rP⋯P=2rM―P), where P ⋯ P is the internuclear phosphine distance (3.049 Å) and M—P is the average Co—P distance (2.188 Å). See: Dierkes, P.; van Leeuwen, P.W. N. M. J. Chem. Soc. Dalton Trans. 1999, 1519.
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Bott, S.G., Yang, K. & Richmond, M.G. X-ray diffraction structure of Co2(CO)4(μ-PhC≡CH)[(Z)-Ph2PCH=CHPPh2[: proof for diphosphine ligand chelation. Journal of Chemical Crystallography 30, 627–632 (2000). https://doi.org/10.1023/A:1011940014273
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DOI: https://doi.org/10.1023/A:1011940014273