环上双氟取代三联苯类液晶化合物的量子化学研究

Quantum-chemical studies on difluorine-substituted triphenyl series crystal compounds

运用AM 1和PM 3两种SCF MO方法 ,通过能量梯度全优化计算 ,给出了对环上双氟取代三联苯类液晶化合物的稳定几何构型、电子结构和生成热、偶极矩、前线分子轨道能级等分子的基本性质。联系有机结构理论进行了分析和讨论。初步阐明了其分子结构与介电各向异性之间的关系 。

AM1 and PM3 SCF-MO calculation have been performed to obtain molecule geometries of difluorine-substituted tri-phenyl series crystal compounds by energy gradient completed optimization. For all optimized configurations, there is no imaginary frequency in vibrational analysis. The stable configuration, electronic structure, and some structure parameters of molecule (heat of formation, dipole moment and energy level of frontal molecule orbital, etc.) for title compounds are first reported. The calculated results are fully discussed with respect to the organic structure theory. It was illuminated preliminary that relation between the dielectric anisotropy and molecule structure, which will provide a clues for the research of the new liquid crystal molecule.