IDENTIFICATION OF THE STEREOISOMERS OF 1,2,3,4-TETRAMETHYL-1,2,3,4-TETRAPHENYLCYCLOTETRASILANE

The configurations of three synthetically available stereoisomers (tttt, ttcc, and tctc) of 1,2,3,4-tetramethyl-1,2,3,4-tetraphenylcyclotetrasilane have been unambiguously assigned by using spin labeling techniques and by preparing chemical derivatives. 1J(C-Si), 2J(C-Si), and 3J(C-Si) values were determined for the three stereoisomers with C-13-labeled methyl groups. The dominating isomer resulting from the synthesis possesses an all-trans structure and can be isolated in up to 95% purity.