Department of Chemistry, Tohoku University, Aoba-ku, Sendai 980-8578, Japan.
Chem Asian J. 2013 Jun;8(6):1177-81. doi: 10.1002/asia.201300098. Epub 2013 Mar 7.
Silacyclophanes possessing two disilanyl pillars were synthesized from tricyclic heteroarenes in one-pot synthetic procedures. The step-like anti structures of three congeners bearing two heteroarene units were revealed in single crystals by X-ray crystallographic analysis. Depending on the structures of aromatic units, torsion angles at the disilanyl pillars altered to maintain the overall step-like molecular structures. The structure, however, fluctuated between anti and syn conformers in a solution phase despite the presence of eight methyl groups on the ring periphery. The analysis of the coalescence temperature with NMR spectroscopy showed the fundamental energetics of the dynamics. The subtle structural differences affected the dynamic behavior of the silacyclophanes.
具有两个二硅烷基支柱的硅杂环戊二烯是通过三环杂芳烃一锅法合成的。通过 X 射线晶体学分析，在单晶中揭示了三个具有两个杂芳烃单元的同系物的阶梯式反式结构。根据芳环单元的结构，二硅烷基支柱上的扭转角发生变化，以保持整体阶梯式分子结构。然而，尽管环周围有八个甲基，但在溶液相中，结构在反式和顺式构象之间波动。通过 NMR 光谱分析的融和温度表明了动力学的基本能量。细微的结构差异影响了硅杂环戊二烯的动态行为。
