【摘要】 本文用量子化学方法从理论上研究了双(15-冠-5)二苯乙烯及其与一种或两种碱金属阳离子(Li~+、Na~+和K~+)络合的衍生物.碱阳离子的配位导致冠醚的部分收缩,直接影响分子的电荷分布和分子轨道能级.碱金属离子种类的数量对吸收光谱和第二超极化率有显著影响.在双(15-冠-5)二苯乙烯中加入1个碱金属离子时,吸收光谱发生明显红移,第二超极化率显著升高;在双(15-冠-5)二苯乙烯中加入2个碱金属离子时,吸收光谱发生明显蓝移,第二超极化率显著降低.另一方面,随着碱金属离子半径的增大,所研究配合物的第二超极化率逐渐增大.表明该第二超极化率对碱金属阳离子的数量和半径敏感,因此可以利用三阶非线性光学响应作为检测碱金属离子数量和类型的信号.更多还原

【Abstract】 Bis(15-crown-5)-s t ilbenes containing crown ether parts have been widely used in a variety of chemical applications,such as cation detectors,because of their ability to selectively bind to alkali metal cations,Bis(15-crown-5)-stilbenes and its derivatives with complexation of oneor two-alkali metal cation(Li~+,Na~+ and K~+) have been theoretically investigated by quantum chemistry methods.The coordination of alkali cations results in partial shrinkage of crown ethers,which directly affected natural distribution analysis charges and molecular orbital energy levels.The number of alkali metal ions has significant effects on absorption spectra and mean second hyperpolarizability.When one alkali metal ion was added to the anticonformer of bis(15-crown-5)-stilbene,the absorption spectra were obviously redshifted and the mean second hyperpolarizability values were slightly increased;while two alkali metal ions were added to bis(15-crown-5)-stilbene,the absorption spectra were obviously blue shifted and the mean second hyperpolarizability values decreased.On the other hand,as the radius of the alkali ions increased,the mean second hyperpolarizability values of the compounds increased gradually.It is indicated that the mean second hyperpolarizability value is sensitive to the number and radius of the alkali metal cations,thus the third order nonlinear optical response can be used as a signal to detect the number and type of alkali metal ions.更多还原