二芳基氨(硼)-π-碳硼烷三元化合物的二阶非线性光学性质的理论研究

采用密度泛函理论(DFT)方法对二芳基氨(硼)-π-十二顶点碳硼烷三元化合物的结构及二阶非线性光学(NLO)性质进行计算.结果表明,化合物共轭桥长度及二芳基氨(硼)对化合物偶极矩的影响较小.随着分子共轭桥的增长,分子的电子空间范围R2增大,从而使极化率和第一超极化率增大.通过分析化合物的电子光谱和对应的分子轨道组成可知,分子中电荷转移主要发生在二芳基氨(硼)和π-桥之间,碳硼烷的贡献较少.二芳基氨和二芳基硼的供电子能力差异可以调节分子的二阶NLO响应.

Theoretical Study on the Second-order Nonlinear Optical Properties of Diaryl Ammonia( Boron)-π-carborane Ternary Compounds

The structures and second order nonlinear optical( NLO) properties of diaryl ammonia( boron)-π-twelve vertex carborane ternary compounds were studied using density functional theory( DFT) methods. The results show that the conjugated bridge length and diaryl ammonia( boron) of compounds have relatively small influence on their dipole moments. Along with the lengthening of the conjugate bridge and the increases of electronic space scope 〈R2〉, polarizability and the first hyperpolarizability increase. From the analysises of electronic spectra and the corresponding molecular orbitals of compounds, it is found that the intramolecular charge transfers within these compounds occur mainly between diaryl ammonia ( boron ) and the π-bridge, while carborane has less contribution. In addition, the differences of the electron donating ability between diaryl ammonia and diaryl boron can adjust second-order NLO responses of these compounds.