Novel silicon and tin compounds were synthesized by the reaction of lithium salts of 1,3-di-phenyl-1,1,3,3-tetramethyldisilazane H(DPTMDS) and 1,1,3,3,5,5-hexamethylcyclotrisilazane H3(HMCTS) with SiCl4 and SnCl4, respectively. The reactions with H(DPTMDS) yield the substitution products (DPTMDS)2SiCl2 and (DPTMDS)2SnCl2. In contrast, the reactions with the cyclic silazane H3(HMCTS) lead to a large variety of products due to the competition of substitution reactions and ring contractions. The resulting new compounds were characterized by elemental analyses, NMR spectroscopy, and single crystal X-ray structure analyses. [ABSTRACT FROM AUTHOR]