New chalcogen derivatives of silicon possessing adamantane and noradamantane structures

The reaction of Si2Cl4Me2 (1) with Li2Se in THF yields exclusively the noradamantane (MeSi)4Se5 (4). The sulfur analogue (MeSi)4S5 (3) could be obtained from 1, MeSiCl3, H2S and NEt3. Reactions of the disilylmethane CH2(SiMeCl2)2 (5c) with either H2S/NEt3 or Li2E (E=Se, Te) produced the new adamantanes (MeSi)4(CH2)2E4 (E=S (6), Se (7) and Te (8)). Similar reactions of mixtures of 1 and 5c resulted in the formation of the noradamantanes (MeSi)4(CH2)E4 (E=S (9), Se (10)). All compounds were characterized by multinuclear NMR spectroscopy. The crystal structures of 3, 6, 7, 8·CDCl3 and 9 are reported.