I ) For reviews of disilene, see: (a) West, R. Pure Appl. Chem. 1p84, 56, I , 163-173. (b) West, R.; Fink, M. J.; Michalczyk, M. J.; De Young, D. J.; Michl, J. In Organosilicon and Bioorganosilicon Chemistry; Sakurai, H., Ed.; Ellis Horwood Ltd.: New York, 1985; Part 1, Chapter 1, pp 3-14. (2) (a) Michalczyk, M. J.; West, R.; Michl, J. Organometallics 1984, 4, 826-829. (b) Fink, M. J.; Michalczyk, M. J.; Haller, K. J.; Michl, J.; West, R. Organometallics 1984, 3, 793-800. (c) Michalczyk, M. J.; Fink, M. J.; De Young, D. J.; Carlson, C. W.; Welsh, K. M.; West, R.; Michl, J. Silicon, Germanium, Tin and Lead Compounds, in press. (d) Raabe, G.; Michl, J. Chem. Rev. 1985.85, 419-509.(3) All new compounds were characterized by 'H NMR, high-resolution, MS, and elemental analysis.