典型三环杂环化合物电子结构和性质的DFT研究

DFT investigation on the electronic structures and properties of tricyclic fused heterocyclic compounds

采用杂化的DFT理论,研究了6种典型三环稠杂环化合物的几何结构、电子密度拓朴结构、NICS以及HOMO-LUMO能级差、电子亲和势和电离能等性质。研究表明,6种三环化合物均为平面结构,分子体系中所有化学键都具有π键特征,环平面上存在较强的共轭作用。这6种化合物具有较小的HOMO-LUMO能级分离值(2.22 eV～3.71 eV),较大的电子亲和势和较大的电离能。因此,在导电聚合物分子设计中,三环杂环化合物可作为良好的电子受体引入共轭聚合物分子。三环杂环化合物结构单元的引入将有利于加强体系π电子的离域,降低聚合物的能隙和增加聚合物体系还原掺杂态的稳定性。

The geometric structures, topological properties of electron density, NICS, HOMO-LUMO energy separation, electron affinity and ionization potential of six tricyclic fused heterocyclic compounds were analyzed systematically by DFT method. The theoretical result shows that all the studied compounds have a highly symmetric structure with a rigid planar. Topological and NICS analysis confirm that there exists considerable conjugation and aromaticity over the rings for these tricyclic fused heterocyclic compounds. The theoretical HOMO-LUMO energy separations of these compounds are relatively small （in the range of 2.22 eV-3.71 eV）, and the electron affinities and ionization potentials are relatively large. Those properties indicate that these tricyclic fused heterocyclic compounds may be promising candidates for building intrinsically conductive organic polymers.