New Aspect of Tetrahedrane : Synthesis and Properties of Highly Strained σ-π Condugated Molecules

四面体是一种具有高张力碳-碳σ键的碳氢化合物。由于骨架极度紧张，C-C σ-键轨道能级的增加导致四面体σ-框架与相邻π-轨道系统之间的σ-π共轭。我们研究了全氟芳基取代的四面体的合成、结构分析和性质。迄今为止，还没有硫取代四面体等稳定杂原子的报道。我们报道了二苯基二硫醚与四面体锂的亲核取代反应制备的苯硫基四面体的合成、结构和性质。我们的四面体通过 NMR 和 X 射线晶体学进行了全面表征。在测量全氟芳基取代的四面体的紫外-可见光谱时，观察到相对于未取代的全氟苯显着的红移。它表明四面体σ-骨架和全氟芳基π-体​​系的扩展σ-π共轭。

Tetrahedrane is a hydrocarbon with highly strained carbon-carbon σ bonds. Because of the extremely strained skeleton, the increase in the energy level of C-C σ-bond orbitals results in the σ-π conjugation between tetrahedrane σ-frame with adjacent π-orbital system. We have investigated the synthesis, structural analysis and properties of perfluoroaryl substituted tetrahedranes. Up to now, there is also no report of stable heteroatom such as sulfur substituted tetrahedranes. We report the synthesis, structure and properties of phenylthio tetrahedranes which was prepared by the nucleophilic substitution of diphenyldisulfide and tetrahedranyllithim. Our tetrahedranes were fully characterized by NMR and X-ray crystallography. On the measurement of UV-vis spectrum of perfluoroaryl substituted tetrahedranes, a significant bathochromic shift relative to the non-substituted perfluorobenzene was observed. It indicate the extended σ-π conjugation of tetrahedrane σ-frame and perfluoroaryl π-system.