含苯咔唑基12顶点碳硼烷衍生物二阶非线性光学性质的DFT研究

The DFT study on second-order NLO properties of 12-Vertex carborane compounds with phenyl carbazoles

采用密度泛函理论方法(DFT)计算讨论了系列含苯咔唑基的碳硼烷衍生物的电子结构及其二阶非线性光学(NLO)性质.结果表明,化合物中共轭桥的长度对其偶极矩和极化率影响较小,而对其第一超极化率影响较大.随着分子共轭桥的增长,其二阶NLO响应逐渐增大.用氟取代碳硼烷的氢对邻位碳硼烷体系影响较大,氟代邻位碳硼烷体系的偶极矩、极化率和第一超极化率都有显著提升,其中氟代邻位碳硼烷分子的第一超极化率是未取代分子的8倍,因此氟代邻位碳硼烷可以有效地调节分子的二阶NLO响应.

The NLO properties and the electronic spectra of a series of 12-vertex carborane compounds with phenyl carbazoles were investigated by using the density functional theory(DFT)method.The results show that the length of the conjugated bridge has little influence on the dipole moment and the polarizability value,but has great influence on its first hyperpolarizability.The second-order NLO response of the molecule increases gradually.The hydrogen of the fluorine substituted for the carborane has great influence on the ortho-carborane system.The dipole moment,the polarizability and the first hyperpolarizability of the fluorocarborane system have increased significantly,and the first super class polarizability of the fluorocarbon borane molecule is 8 times that of the substituent molecule.The ortho substituted carbon borane can effectively regulate the two order NLO response of molecules.