香蕉型液晶的电子结构计算和电激发特性

Electronic Structure and Electron Transition of Banana-Shaped Liquid Crystals

用舒克紧束缚法计算了一种新型香蕉型液晶1,3-phenylene bis[-4-（4’-nonyloxy）phenyliminomethyl]benzoate的电子结构，结果表明：LUMO和HOMO的能量差别主要是受到香蕉型液晶的中心核、桥键（—COO—）的影响，而烷基尾对香蕉型液晶电子结构的影响不大；在6种可能跃迁中，只有能量最低的两种（π→π，n→π）在200-800nm可见光范围内是经常发生的。对于这种香蕉型液晶，电子激发主要发生在4．0eV（310nm）和1．7eV（730nm）处。

The electronic structures of the banana-shaped liquid crystal 1,3-phenylene bis E4-（4＇-nonyloxy） phenyliminomethyl] benzoate were calculated with Huckel tight-binding method. The effects of the central core, the linkages and the alkyl tails in the two-branched legs of the banana-shaped liquid crystal were discussed. Among the six transitions outlined, only the two lowest energy ones （π→π,n→π） are often achieved by the energies available in the 200-800 nm spectrum. Energetically favoured electron excitation will take place at 4.0 （310 nm） and 1.7 eV （730 nm）, respectively, for the studied molecule.