Catenated Group 14 Compounds. Synthesis, Structural and Spectral Characterization, and Chemistry of the Chains Me3CSiMe2GeMe2SnR3 (R = Me, Ph)

The permethylated catenated group 14 compound with the periodic chain C−Si−Ge−Sn is reported, 1a, together with the triphenyltin analog, 1b . Complete spectral characterization, including multinuclear NMR, is provided. The single-crystal structure of 1b is reported: the bond lengths C t -Bu −Si, Si−Ge, and Ge−Sn, 1.900(9), 2.386(2), and 2.608(1) Å, respectively, are all in the normal range. Bond angle measurements indicate that the tert -butyl group dominates the structure resulting in significant distortions about the Ge atom. Photochemical treatment of 1a resulted in elimination of Me 2 Ge and Me 2 Sn, with a small amount of direct Ge−Sn cleavage. Treatment of 1a with n -butyllithium resulted in the predominant formation of Me 3 CSiMe 2 GeMe 2 Li and Me 3 Sn( n -Bu). Both the photochemical and n -BuLi reactions of 1a also produced (Me 3 CSiMe 2 GeMe 2 ) 2 as a significant byproduct.