Group 14 chalcogenides featuring a bicyclo[3.3.0]octane skeleton

Reactions of mixtures of Cl2MeSiSiMeCl2 (1) and Me2MCl2 (M=Si, Ge, Sn) with either H2S/NEt3 or Li2E (E=Se, Te) yielded the bicyclo[3.3.0]octanes Me2M(E)2Si2Me2(E)2MMe2. A carbon containing analog, (CH2)5C(S)2Si2Me2(S)2C(CH2)5, was prepared from 1 and (CH2)5C(SH)2. Crystal structures of three of these compounds were determined and the observed conformations of the bicyclo[3.3.0]octane skeletons compared with results of density functional theory calculations. Another class of silchalcogenides featuring a bicyclo[3.3.0]octane skeleton, E(Me2Si)2Si2Me2(SiMe2)2E, was formed from the doubly branched hexasilane (ClMe2Si)2Si2Me2(SiMe2Cl)2 and H2S/NEt3 or Li2E. All products were characterized by multinuclear NMR (1H, 13C, 29Si, 77Se, 119Sn, and 125Te).