1. Adams, R. D., Yamamoto, J. H., Holmes, A. and Baker, B. J., Organometallics, 16, 1430, (1997) .
2. Cooper, S. R., in Crown Compounds : Toward Future Applications, Ch. 15, S. R. Cooper,Ed. ; VCH Publishers, New York (1992) ; (b) Cooper, S. R. and Rawle, S C., Struc. andBonding, 1990, 72, 1 ; (c) Blake, A. J. and Schröder,M., Adv. Inorg. Chem., 1990, 35, 1.
3. Boorman, P. M., Kerr, K. A., Kidd, R. A., Moynihan, K. J. and Valentine, K. A., J. Chem. Soc.,Dalton Trans., 1982, 1401.
4. Bernal, I., Atwood, J. L., Calderazzo, F. and Vitali, D., Isr. J. Chem., 1977, 15,153 ; (b) Bernal, I., Atwood, J. L., Calderazzo, F. and Vitali, D., Gazz. Chem. Ital., 1976,106, 971.
5. Roesky, H. W., Gries, T., Jones, P. G., Weber, K.-L. and Sheldrick, G. M., J.Chem. Soc., DaltonTrans., 1984, 1781.