The chlorodisilanes SiClMe2 SiClMe2 (1), SiCl2Me SiCl2Me (2), SiCl3 SiCl3 (3) and a 9: 1 mixture of 2 and SiCl3 SiCl2Me (4) were reacted with the electron-rich alkene tetrakis- (dimethylamino)-ethylene (TDAE) in n-hexane as well as in polar solvents. While 1 gave no reaction at all, 3 underwent a disproportionation reaction into SiCl4 and Si (SiCl3) 4. Also 2 and mixtures of 2 and 4 were disproportionated into MeSiCl3 (2a) and ...