Five-, six- and eight-membered ring organosilicon chalcogenides of the types Z2(SiMe2)2E (Z = Me2Si, H2C; E = S, Se, Te), Z(SiMe2E)2MR2(Z = Me2Si, H2C, O; E = S, Se, Te; M = Si, Ge, Sn, R = Me, Ph) and (SiMe2ZSiMe2E)2(Z = Me2Si, H2C; E = S, Se)

Abstract

Reactions of ClMe2Si–Z–SiMe2Cl (Z = SiMe2 (1a), CH2 (1c), O (1e)) with Li2E (E = S, Se) yielded eight-membered ring compounds (SiMe2ZSiMe2E)2 (3a–d) as well as acyclic oligomers (SiMe2ZSiMe2E)x of different chain lengths. If 1:1 molar mixtures of 1a, 1c or 1e and a diorganodichlorosilane, -germane or -stannane (R2MCl2) are reacted with Li2E (E = S, Se, Te), six-membered ring compounds Z(SiMe2E)2MR2 (4a–7g) are formed exclusively. Five-membered rings Z2(SiMe2)2E (Z = SiMe2 (8a–c), CH2 (9a–c); E = S, Se, Te) are obtained starting from the tetrasilane ClMe2Si–(SiMe2)2–SiMe2Cl (1b) or the disilylethane ClMe2Si–(CH2)2–SiMe2Cl (1d) by treatment with Li2E. All products were characterized by multinuclear NMR spectroscopy (1H, 13C, 29Si, 119Sn, 77Se, 125Te, including coupling constants) and the effects of the different ring sizes towards NMR chemical shifts are discussed.