The synthesis, and molecular and electronic structure of dodecacarbonyl(µ₄-η²- prop-1-ene-1,1-diyl)tetrairon, Fe₄(CO)₁₂(µ₄-η ²-C=CHCH₃) 

Abstract

The µ₄-vinylidene cluster Fe₄(CO)₁₂(µ₄-η²-C =CHCH₃) has been prepared by the sequential reaction of Fe₄(CO)₁₂[C=C(CH₃)(OCH₃ )], with lithium triethylhydroborate and trimethylsilyl trifluoromethanesulfonate. The cluster has an open butterfly arrangement of four iron atoms with the prop-1-ene-1,1-diyl ligand bound to all four iron atoms in a manner giving an axial C=C bond, perpendicular to both the mutually perpendicular Fe–Fe vectors between the wingtip iron atoms (Fe_w) and between the hinge iron atoms (Fe_h). The vinylidene carbon atom lies below the Fe_w–Fe_w vector, essentially inside the Fe₄ core. Molecular orbital calculations using the Fenske–Hall method were carried out for the cluster, showing that the geometry of the Fe₄C=CHCH₃ fragment results from overlap between the formal C=C double bond and the two Fe_w iron atoms. Comparisons are drawn between Fe₄(CO)₁₂(µ₄-η²-C =CHCH₃) and other Fe₄ vinylidene clusters.

References

1. E. Sappa, A. Tiripicchio and M. Tiripicchio Camellini, Inorg. Chim. Acta, 1980, 41, 11.
2. A. J. Carty, S. A. MacLaughlin and N. J. Taylor, J. Chem. Soc., Chem. Commun., 1981, 476.
3. P. Brun, G. M. Dawkins, M. Green, R. M. Mills, J.-Y. Salaün, F. G. A. Stone and P. Woodward, J. Chem. Soc., Dalton Trans., 1983, 1357.
4. A. J. Carty, N. J. Taylor, E. Sappa and A. Tiripicchio, Inorg. Chem., 1983, 22, 1871.
5. E. Sappa, A. Tiripicchio and M. Tiripicchio Camellini, J. Organomet. Chem., 1983, 246, 287.
6. J. C. Jeffrey, B. F. G. Johnson, J. Lewis, P. R. Raithby and D. A. Welch, J. Chem. Soc., Chem. Commun., 1986, 318.
7. T. Albiez, A. K. Powell and H. Vahrenkamp, Chem. Ber., 1990, 123, 667.
8. Y. Chi, S.-H. Chuang, L.-K. Liu and Y.-S. Wen, Organometallics, 1991, 10, 2485.
9. R. Rumin, F. Robin, F. Y. Pétillon, K. W. Muir and I. Stevenson, Organometallics, 1991, 10, 2274.
10. A. B. Antonova, A. A. Johansson, N. A. Deykhina, A. G. Ginzburg, E. D. Korniyets, S. V. Kovalenko, N. I. Pavlenko, P. V. Petrovskii, A. I. Rubaylo and I. A. Sukhina, Inorg. Chim. Acta, 1995, 230, 97.
11. J. S. Bradley, S. Harris, E. W. Hill and M. Modrick, Polyhedron, 1990, 9, 1809.
12. C. J. Adams, M. I. Bruce, B. W. Skelton and A. H. White, J. Chem. Soc., Dalton Trans., 1992, 3057.
13. J. S. Bradley, S. Harris, J. M. Newsam, E. W. Hill, S. Leta and M. Modrick, Organometallics, 1987, 6, 2060.
14. T. Kawasaki, Y. Nonaka, M. Kobayashi and M. Sakamoto, J. Chem. Soc., Perkin Trans. 1, 1991, 2445.
15. M. Brookhardt and R. C. Buck, J. Organomet. Chem., 1989, 370, 111.
16. J. R. Andrews, S. F. A. Kettle, D. B. Powell and N. Sheppard, Inorg. Chem., 1982, 21, 2874.
17. C. K. Johnson, ORTEP, Report ORNL-5138, Oak Ridge National Laboratory, Oak Ridge, TN, 1976.
18. S. Harris and J. S. Bradley, Organometallics, 1984, 3, 1086.
19. E. W. Hill and J. S. Bradley, Inorg. Synth., 1989, 27, 101.
20. International Tables for X-Ray Crystallography, Kynoch Press, Birmingham, 1969, vol. 1.
21. International Tables for X-Ray Crystallography, Kynoch Press, Birmingham, 1974, vol. 4.
22. G. M. Sheldrick, SHELXTL, University of Göttingen, 1986.
23. M. B. Hall and R. F. Fenske, Inorg. Chem., 1972, 11, 768.
24. J. W. Richardson, W. C. Nieupoort, R. R. Powell and W. F. Edgell, J. Chem. Phys., 1962, 36, 1507.
25. E. Clementi, J. Chem. Phys., 1964, 40, 1944.