聚并苯和聚并吡啶类化合物非线性光学性质及其分子材料设计

Molecule Material Design of a Class of PAS and PPY Polymer with Nonlinear Optical Properties

选取聚并苯、聚并吡啶和聚并吡嗪的 3种共振结构为基体 ,计算不同共轭单体齐聚物的结构及被取代后的聚合物二阶和三阶非线性光学系数 .结果表明 ,聚合物的二阶非线性光学系数与其单体相比有显著增大 ,被—NH2 和 NO2 取代后的聚并苯、聚并吡啶和聚并吡嗪的非线性光学系数又在聚合物的基础上进一步大幅度增加 ,有的增加 2～ 3个数量级 .在非取代的聚合物中 ,聚吡啶各种结构的二阶非线性光学系数均较大 ;取代聚合物中 ,单—NH2 和—NO2 取代的聚并苯 ,尤其是反式共振结构聚并苯的二位— NH2 和五位—NO2 取代结构的聚合物二阶非线性光学系数高达 3 .2 7× 1 0 - 2 7esu,说明这种— NH2 和 -NO2 取代后的聚并苯是一种很好的非线性光学材料 .

Based on the three resonant structures of polybenzene(PAS), Polypyridine(PPY) and Polypyrazine(PPYZ), the nonlinear optical(NLO) coefficients of different conjugate monomer oligmers and substituted polymers were calculated. The results showed that the second\|order NLO coefficient of the polymer rises evidently comparing with that of its monomer. The NLO coefficients of PAS, PPY and PPYZ substituted by \{\_NH\-2\} and \_NO\-2 have a remarkable increase based on the polymers, even reach more than two to three order of magnitude. The second\|order NLO coefficients of all kinds of PPY are all large in the unsubstituted polymers. The value \%β\% of PAS substituted by single \{\_NH\-2\} and \_NO\-2, especially the 2 \_NH\-2 and 5 \_NO\-2 substituted \%trans\%\|resonance structure is as high as 3.27×10\+\{-27\} esu. It indicates that PAS substituted by \_NH\-2 and \_NO\-2 is a intriguing candidate of NLO material.