Abstract A series of novel hydrazinosilanes, eg the bis (hydrazino) dimethylsilanes I and II, the amino-hydrazino-dimethylsilanes III–V, the bis (hydrazino) disilane VI with (+ 3) valent Si and (− 2) valent N and the trialkoxysilylhydrazines VII and VIII, were prepared as shown in the reactions (1) to (6) and characterized by their physical properties.