1. Agnus, Y., Louis, R., and Weiss, R. (1980)J. Chem. Soc. Chem. Commun., 867?869.
2. Baldwin, D. A., Copperthwaite, R. G., Faisca, A. M. M., and Markwell, A. J. (1982) unpublished results.
3. Birker, P. J. M. W. L., and Freeman, H. C. (1976)J. Chem. Soc. Chem. Commun., 312?313.
4. Birker, P. J. M. W. L., and Freeman, H. C. (1977)J. Am. Chem. Soc. 99, 6890?6899.
5. Birker, P. J. M. W. L., Reedijk, J., Verschoor, G. C., and Jordanov, J. (1982)Acta Cryst. B 38, 2245?2247.