Nucleophilic addition via metal–metal bond cleavage in an osmium–antimony cluster

Abstract

The room-temperature reaction of a number of two-electron nucleophiles with the osmium–antimony cluster [Os₃(µ-H)(CO)₁₀(µ-SbPh₂)] 1 gave adducts [Os₃H(CO)₁₀(µ-SbPh₂)L] 2 (L = PPh₃ a, AsPh₃ b, SbPh₃ c or CO d), in which the antimony-bridged Os–Os bond has been cleaved in order to accommodate the incoming ligand. X-Ray crystallographic studies on 2b and 2c confirmed that the ligands L occupied an equatorial site of the Os₃Sb framework, while NMR studies indicated that the clusters 2a–2c existed as isomeric mixtures, which probably differ in the arrangements of the ligand L relative to the antimony vertex. The reaction leading to the formation of 2b, which was carried out at elevated temperature, also led to decarbonylation to a substituted analogue of 1 in which the ligand L was on the unbridged osmium.

References

1. For example, T. P. Fehlner, Inorganometallic Chemistry, Plenum, New York, 1992; W. A. Herrmann, Angew. Chem., Int. Ed. Engl., 1986, 25, 56; J. N. Nicholls, Polyhedron, 1984, 3, 1307.
2. K. H. Whitmire, Adv. Organomet. Chem., 1998, 42, 1.
3. W. K. Leong, Bull. Sing. N. I. C., 1996, 24, 51.
4. For example, K. Guldner, B. F. G. Johnson, J. Lewis, A. D. Massey and S. Bott, J. Organomet. Chem., 1991, 408, C13; K. Guldner, B. F. G. Johnson and J. Lewis, J. Organomet. Chem., 1988, 355, 419; A. J. Deeming, R. E. Kimber and M. Underhill, J. Chem. Soc., Dalton. Trans., 1973, 2589.
5. K. Guldner, B. F. G. Johnson, J. Lewis, S. M. Owen and P. R. Raithby, J. Organomet. Chem., 1988, 341, C45.
6. B. F. G. Johnson, J. Lewis, A. J. Whitton and S. G. Bott, J. Organomet. Chem., 1990, 389, 129.
7. For example, J. B. Keister and J. R. Shapley, Inorg. Chem., 1982, 21, 3304; W. Ehrenreich, M. Heberhold, G. Hermann, G. Suess-Fink, A. Gieren and T. Huebner, J. Organomet. Chem., 1985, 294, 183; S. C. Brown and J. Evans, J. Chem. Soc., Dalton. Trans., 1982, 1049; E. A. V. Ebsworth, A. P. McIntosh and M. Schroder, J. Organomet. Chem., 1986, 312, C41; F. W. B. Einstein, R. K. Pomeroy and A. C. Willis, J. Organomet. Chem., 1986, 311, 257.
8. C. K. Johnson, ORTEP, Report ORNL-5138, Oak Ridge National Laboratory, Oak Ridge, TN, 1976.
9. N. Viswanathan, E. D. Morrison, G. L. Geoffroy, S. J. Geib and A. L. Rheingold, Inorg. Chem., 1986, 25, 3100.
10. S. B. Colbran, P. T. Irele, B. F. G. Johnson, F. J. Lahoz, J. Lewis and P. R. Raithby, J. Chem. Soc., Dalton. Trans., 1989, 2023.
11. W. K. Leong and G. Chen, unpublished work.
12. W. K. Leong, F. W. B. Einstein and R. K. Pomeroy, J. Cluster Sci., 1996, 7, 121.
13. SMART, version 4.05, Siemens Energy & Automation Inc., Madison, WI, 1995.
14. G. M. Sheldrick, SADABS, University of Göttingen, 1996.
15. SHELXTL, version 5.03, Siemens Energy & Automation Inc., Madison, WI, 1995.