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

四面体烷是一种具有高应变碳-碳σ键的碳氢化合物。由于骨架高度应变，C-C σ-键轨道能级的增加导致四面体σ-框架与相邻π-轨道体系之间的σ-π共轭。研究了全氟芳基取代四面体的合成、结构分析和性质。到目前为止，也没有硫取代四面体等稳定杂原子的报道。报道了以二苯基二硫化物和四面体锂为原料，采用亲核取代法制备的苯基硫代四面体烷的合成、结构和性质。我们的四面体通过核磁共振和x射线晶体学完全表征。在全氟芳基取代四面体的紫外-可见光谱测量中，观察到相对于未取代的全氟苯有明显的色移。证明了四面体σ-框架与全氟芳基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.