【作者】 石东；

【导师】 苏忠民；

【作者基本信息】 东北师范大学 ， 物理化学， 2007， 硕士

【摘要】 在过渡金属配合物中,二茂铁类衍生物是一类具有很好的光电功能的化合物。长期以来,有关其光电性质的实验和理论研究颇多,这类化合物在非线新光学领域一直是个研究的热点化合物。近年来,大量新型二茂铁化合物被合成出来。我们借助密度泛函(DFT)和含时密度泛函(TDDFT)方法选取和设计了一系列二茂铁类衍生物,这类衍生物具有D-П-A型结构特点。我们通过改变连接电子给体基团D和电子受体基团A之间的П结构桥连双自由基(1,2-亚乙烯基,简称亚乙烯基)的数目,即改变D-П-A结构中П结构的长度得到不同的衍生物。我们计算了这些衍生物的结构、光谱和二阶非线性光学系数,发现随着亚乙烯基数目的增多,分子的二阶非线性光学系数线性增大。我们也在吸电子基团上引入不同的取代基并计算了其结构、光谱与二阶非线性光学性质,结果表明,随着取代基的共轭程度和吸电子能力的增大,体系的二阶非线性光学系数随之增大。我们进一步从分子轨道的层次分析了不同结构的分子的光谱特征与其电子态之间的关系,结果表明,该类化合物随着D与A之间桥连的亚乙烯基数目的增多,其最大吸收峰红移,这是由于参与跃迁的高能级轨道中成分中离域到了乙烯片段上,电子的离域化使得轨道能级降低,吸收峰红移。同样我们也计算了在吸电子基团上引入不同取代基时分子的光谱性质,发现取代基的引入使得吸收的光子主要用于激发点在吸电子基团与引入的侧链之间跃迁。显然最大吸收峰会随着侧链共轭程度的增大而红移。更多还原

【Abstract】 Among various kinds of transition metal coordinates, Ferrocenyl-containing organometallic complexes possess rich opt-electric properties. Such complexes have been drawing much experimental and theoretical research attention in various field including nonlinear optics. Recently, a great amount of ferrocene derivatives have been synthesized. We studied the structural, absorption spectral and the second-order nonlinearitis properties of a series of ferrocene derivatives. These complexes we studied possess D-П-A structural property. Results obtained by DFT and TDDFT and SOS method showed that changing the number of the bridging ethyldiene can change the second-order nonlinearities of different complex with the same donor and acceptor groups. For the same donor and acceptor groups, the introduction of an conjugated substituent, the second-order nonlinearities increased. Moreover, with the conjugation extent and the electron-withdrawing strength increased, the increase of the second-order nonlinearities were magnified. Result on the absorption spectra and detail analysis of the molecular orbital properties showed that, in D-П-A structure characterized ferrocenyl complexes(a, b, d) without any substituents, electrons were excited from the ferrocenyl moiety to the p-nitrophenyl groups, the delcolization of the high-level orbital to which the ecletron was excited can lead to red shift of the max absorption wavelength. While in the case with substituents the excitation that most contributed to max-wavelength absorption was not from the ferrocenyl groups, such excitations localized between the substituents and the p-nitrophenyl moiety. So it is obvious substituent of large conjugation will lead to red shift of the corresponding absorption wavelength.更多还原