Two-photon absorption and nonlinear optical properties of octupolar molecules.
Two-photon absorption and nonlinear optical properties of octupolar molecules.
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DOI：
10.1021/ja004226d
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发表时间：
2001-10
影响因子：
15
通讯作者：
Wonho Lee;Hochan Lee;Jin-A Kim;Jun Ho Choi;Minhaeng Cho;S. Jeon;Bong Rae Cho
中科院分区：
文献类型：
--
作者：
Wonho Lee;Hochan Lee;Jin-A Kim;Jun Ho Choi;Minhaeng Cho;S. Jeon;Bong Rae Cho
本文从理论上研究了四种典型八极分子的双光子吸收截面。用有效四态价键三电荷转移模型描述了一般结构-TPA-性能关系。由于强施主或受主的存在，基态电子态的电荷转移特性增加，（i）基态和2重简并激发态之间的跃迁偶极矩阵元增加，（ii）能隙减小，因此（iii）TPA跃迁振幅单调增加。因此，设计策略，以最大化的TPA截面的八极分子的建立。在四态模型的基础上，发现八极分子的第一超极化率与TPA截面成线性关系。用从头计算结果证实了这一理论关系。对双光子吸收截面和第一超极化率进行了Hammett相关分析。
Two-photon absorption (TPA) cross sections of four representative series of octupolar molecules are theoretically investigated. The general structure--TPA-property relationship is described by using the effective four-state valence-bond three-charge-transfer model. As the charge-transfer character of the ground electronic state increases due to the strong donors or acceptors, (i) the transition dipole matrix elements between the ground and 2-fold degenerate excited states increase, (ii) the energy gap decreases, and consequently (iii) the TPA transition amplitude monotonically increases. Thus, the design strategy to maximize the TPA cross section of the octupolar molecule is established. On the basis of the four-state model, the first hyperpolarizability of the octupolar molecule is found to be linearly proportional to the TPA cross section. This theoretical relationship is confirmed by using the ab initio calculation results. The Hammett correlation analysis of the TPA cross section and first hyperpolarizability is also presented.