Aggregation of carbamato ligands around the [Co₄O]⁶⁺ core. Synthesis and structure of the cluster [Co₄O(O₂CNC₉H₁₈)₆] prepared by a novel oxo-transfer reaction of the nitroxyl free radical 2,2,6,6-tetramethylpiperidin-1-oxyl with [Co₂(CO)₈]

Abstract

The novel oxo-centred tetrahedral cobalt cluster [Co₄O]⁶⁺ bridged by six carbamato ligands is prepared in high yield when reacting [Co₂(CO)₈] with an excess of the nitroxyl radical 2,2,6,6-tetramethylpiperidin-1-oxyl; the molecular structure of the title compound is determined by a single-crystal X-ray analysis.

References

1. W. Sümmermann and U. Deffner, Tetrahedron, 1975, 31, 593.
2. A. Caneschi, J. Laugier and P. Rey, J. Chem. Soc., Perkin Trans. 1, 1987, 1077.
3. Z. Ma and J. M. Bobbitt, J. Org. Chem., 1991, 56, 6110.
4. M. F. Semmelhack, C. S. Chou and D. A. Cortes, J. Am. Chem. Soc., 1983, 105, 4492.
5. Y. Y. Lim and R. S. Drago, Inorg. Chem., 1972, 11, 1334; R. M. Richman, T. C. Kuechler, S. P. Tanner and R. S. Drago, J. Am. Chem. Soc., 1977, 99, 1055; R. S. Drago, T. C. Kuechler and M. Kroeger, Inorg. Chem., 1979, 18, 2337; M. H. Dickman and R. J. Doedens, Inorg. Chem., 1981, 20, 2067; R. F. Richardson and R. W. Kreilick, J. Am. Chem. Soc., 1977, 99, 8183; O. P. Anderson and T. C. Kuechler, Inorg. Chem., 1980, 19, 1417.
6. D. Gatteschi, O. Kahn, S. Miller and F. Palacio, Molecular Magnetic Materials, Kluwer Academic, Dordrecht, 1991; O. Kahn, Molecular Magnetism, VCH, Weinheim, 1993; J. S. Miller and A. J. Epstein, Angew. Chem., Int. Ed. Engl., 1994, 33, 385; J. S. Miller, Adv. Mater., 1992, 4, 298; J. S. Miller, Chem. Eng. News., 1995, 73, 30.
7. P. Jaitner, W. Huber, G. Huttner and O. Scheidsteger, J. Organomet. Chem., 1983, 259, C1; P. Jaitner, W. Huber, A. Gieren and H. Betz, J. Organomet. Chem., 1986, 311, 379; P. Jaitner and W. Huber, Inorg. Chim. Acta, 1987, 129, L45.
8. D. Rehder and P. Jaitner, J. Organomet. Chem., 1987, 329, 337.
9. W. G. Klemperer, Angew. Chem., 1978, 90, 258; H. J. Kneuper, P. Härter and W. A. Herrmann, J. Organomet. Chem., 1988, 340, 353; W. McFarlane and H. C. E. McFarlane, in Multinuclear NMR, ed. J. Mason, Plenum, New York, ch. 14, 1987.
10. J. Hulliger, Angew. Chem., Int. Ed. Engl., 1994, 33, 143.
11. (a) F. Bottomley, Polyhedron, 1992, 11, 1707; B. O. West, Polyhedron, 1989, 8, 219; (b) K. Okamoto, T. Konno and J. Hidaka, J. Chem. Soc., Dalton Trans., 1994, 533.
12. K. K. Anderson and A. Graslund, Adv. Inorg. Chem., 1995, 43, 359.
13. K. S. Murray, Adv. Inorg. Chem., 1995, 43, 261.
14. S. Ladas, R. Imbihl and G. Ertl, Surf. Sci., 1989, 219, 88; 1993, 280, 14.
15. Y. Zhang, R. J. Puddeohatt, L. Manojlovic-Muir and K. W. Muir, Chem. Commun., 1966, 2599 and references therein.
16. H. Schmidbauer, S. Hofreiter and M. Paul, Nature, 1995, 377, 503.