【摘要】 对实验室合成的双共轭链分子1,4-二(4-二乙胺基苯乙烯基)-2-[4-(N-甲基-N-羟乙基)氨基-4′-硝基偶氮苯]-5-己烷氧基苯(BSBAB)及合成它的单共轭链分子的单光子和双光子吸收特性在从头计算的基础上利用密度泛函理论进行了研究.分子BSBAB的优化结构显示,组成该分子的横链和纵链除了保持各自的共轭面外,几近相互垂直.因此,分子BSBAB较好地继承了两个单共轭链分子的光学特性.计算结果表明,在低能量范围内,分子BSBAB具有三个双光子吸收峰,分别来自于两个单共轭链分子以及两者的耦合作用.从理论上证明了双共轭链分子BSBAB是一种具有宽带强双光子吸收的分子材料.理论结果和实验结果符合得较好.在HF水平上的响应函数方法进一步证实了有限态求和方法计算结果的可靠性.还给出了电荷转移态的电荷迁移过程.更多还原

【Abstract】 One-photon and two-photon absorption properties of a double-conjugated-segment molecule (BSBAB) composed of two single-conjugated-segment molecules are studied by using density functional theory at ab initio level. The optimized geometrical structure shows that the two single-conjugated-segment parts in molecule BSBAB retain their own coplanarity and are nearly perpendicular to each other, which seems to indicate that the molecule BSBAB contains optical characteristics of both parts. The molecule BSBAB is found to have three two-photon absorption peaks in lowest energy region which are contributed respectively the two single-conjugated-segment parts respectively and the coupling between them. This also demonstrates that the molecule BSBAB is a broadband strong two-photon absorption chromophore. The response theory approach at Hatree-Fock level is used to prove the convergence of results given by the state summation method with truncated approximation. The charge-transfer process between the charge-transfer states is visualized. The theoretical results are in good agreement with the measurements.更多还原