The molecular structures of lithiopentamethyldisilane ([LiSiMe2SiMe3]4, 1a), 2-lithio-1,1,2,3,3-pentamethyl-1,3-diphenyltrisilane ([LiSi(SiMe2Ph)2Me]2, 1b), and 2-lithio-1,1,1,3,3,3-hexamethyl-2-phenyltrisilane ([LiSi(SiMe3)2Ph]2, 1c) have been determined by X-ray diffraction. The silyllithium 1a is a tetramer in the solid state with intramolecular Li···CH3 agostic interactions. The silyllithiums 1b and 1c are dimers with intramolecular lithium-phenyl interactions. The latter adopts a molecular structure with not only an intramolecular Li–Ph interaction, but also an intermolecular Li···CH3 agostic interaction. The structures of these organometallic derivatives show novel features not observed in solvent-coordinated lithiosilanes. These features provide valuable insights into structures that differ markedly from those of lithiosilanes containing coordinated donor solvent molecules.
硫代五甲基二
硅烷([LiSiMe2SiMe3]4,1a)、2-
硫代-1,1,2,3,3-五甲基-1,3-二苯基三
硅烷([LiSi(SiMe2Ph)2Me]2、1b)和 2-二
硫代-1,1,1,3,3,3-六甲基-2-苯基三
硅烷([LiSi(SiMe3)2Ph]2, 1c)的 X 射线衍射结果。
水苏鎓 1a 在固态下是一种四聚体,分子内存在 Li-
CH3 间的激动作用。
水苏鎓 1b 和 1c 是具有分子内
锂-苯基相互作用的二聚体。后者采用的分子结构不仅具有分子内的
锂-苯基相互作用,而且还具有分子间的
锂----- 瞬时相互作用。这些有机
金属衍
生物的结构显示出溶剂配位的
硅烷所没有的新特征。这些特征为研究与含有配位供体溶剂分子的石
硅烷明显不同的结构提供了宝贵的见解。