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

四面体烷是具有高度应变的碳-碳σ键的烃。由于骨架的极度紧张，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四面体的合成、结构分析和性质。到目前为止，也没有报道稳定的杂原子如硫取代的四面体。本文报道了由二苯基二硫醚和四面体锂经亲核取代反应合成的苯硫基四面体化合物的合成、结构和性质。我们的四面体化合物通过核磁共振和X射线晶体学进行了充分的表征。全氟芳基取代的四面体化合物的紫外-可见光谱的测量结果表明，相对于未取代的全氟苯，全氟芳基取代的四面体化合物的紫外-可见光谱发生了明显的红移。这表明四面体σ-框架和全氟芳基π-体系的σ-π共轭是扩展的。

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.