基于密度泛函理论的菲分子结构与光谱研究

摘要

选用密度泛函理论(DET)中的B3LYP方法,在6-311++G(d,p)下对菲分子结构进行优化,计算了其振动频率、极化率及热力学参数,对比了菲分子实测光谱图,首次对其振动频率进行了完全归属.此外,分析并讨论了其前线分子轨道、分子静电势和密立根布局,获得了HOMO-LUMO能隙、分子静电势分布、原子电荷分布等与分子性质密切相关的重要数据,为后续其他多环芳烃分子的光谱检测技术及其光谱和电子结构的分析提供了理论基础.%The optimum molecular geometry of phenanthrene ( PHE) was calculated by the B3 LYP method of density functional theory (DFT) using 6-311 + +G(d,p) basis sets, and data source of vibration frequency, polarizability, and thermo-dynamical parameters were set up. By contrast with the experimental spectra, the vibrational assignment of PHE was discussed. In addition, part of significant parameters such as HOMO-LUMO energy gap, molecular electrostatic potentials and atomic charge were calculated based on the frontier molecular orbital, molecular electrostatic potentials and Mulliken population analyses. This study provides a theoretical support for the spectral detection technology, especially for the analysis of the electronic structure and spectra of PAHs.