1. For the reviews on metallenes and dimetallenes of Group 14 elements, see: (a) R. West, Angew. Chem. Int. Ed. Engl. 26 (1987) 1201.(b) G. Raabe, J. Michl, in: S. Patai, Z. Rappoport (Eds.), The Chemistry of Organic Silicon Compounds, vol. 2, 1989, Wiley, Chichester, p. 1015 Chap. 17.(c) J. Barrau, J. Escudié, J. Satgé, J. Chem. Rev. 90 (1990) 283.(d) T. Tsumuraya, S.A. Batcheller, S. Masamune, Angew. Chem. Int. Ed. Engl. 30 (1991) 902.(e) J. Escudié, C. Couret, H. Ranaivonjatovo, J. Satgé, Coord. Chem. Rev. 130 (1994) 427.(f) M. Driess, H. Grützmacher Angew. Chem. Int. Ed. Engl. 35 (1996) 828.(g) K.M. Baines, W.G. Stibbs Adv. Organomet. Chem. 39 (1996) 275.(h) M. Kaftory, M. Kapon, M. Botoshansky, in: Z. Rappoport, Y. Apeloig (Eds.), The Chemistry of Organic Silicon Compounds, Part 1, vol 2, Wiley, Chichester, 1998, p. 181, Chap. 5.(i) M. Weidenbruch, Eur. J. Inorg. Chem. (1999) 373.(j) P.P. Power, Chem. Rev. 99 (1999) 3463.
2. Hexaaryltetrasilabuta-1,3-diene: A Molecule with Conjugated SiSi Double Bonds
3. Hexaaryltetragermabuta-1,3-diene: A Molecule with Conjugated Ge−Ge Double Bonds
4. For the short preliminary communication see: V.Ya. Lee, M. Ichinohe, A. Sekiguchi, J. Am. Chem. Soc. 122 (2000) 12 604.
5. The First Three-Membered Unsaturated Rings Consisting of Different Heavier Group 14 Elements: 1-Disilagermirene with a SiSi Double Bond and Its Isomerization to a 2-Disilagermirene with a SiGe Double Bond