三氰呋喃苯多烯共轭化合物电子结构对电子光谱及二阶非线性光学性质的影响

以量子化学半经验AM1方法优化几何构型为基础,应用INDO/CI方法对几种具有三维结构的三氰呋喃苯多烯及其脂环化化合物进行电子光谱计算,同时应用完全态求和(SOS)公式计算二阶非线性光学(NLO)系数β.探讨了共轭烯链的长度变化及脂环化对共轭体系电子光谱和β的影响.结果表明,随着共轭链长度增加共轭程度越高,体系β值增大,而λmax红移;烯链的脂环化使β值变小,而λmax变化不大,多烯的脂环化对体系的电子光谱和NLO性质影响不大.

Effect of Electronic Structure on Electronic Spectrum and NLO Property of Phenylpolyene-Bridged Chromophores with Tricyanofuran

Electronic spectra of sterically stabilized phenylpolyene-bridged chromophore with tricyanofuran (TCF) group and their alicyclic ring-locked derivatives structure were investigated with INDO/SCI method based on semiempirical method AM1 optimized geometries. The second-order nonlinear optical coefficients β were calculated according to the sum-over states (SOS) formula. In addition, the effects of chain length and alicyclic ring-locking of the designed systems on electronic spectra and β were investigated. The results indicate that the higher conjugation degree and the longer of the π-conjugated bridge, the larger λ_(max) and β. The little variety of λ_(max) and reduced β values were obtained when the polyene occurred alicyclic ring-locked.