Design of novel nonlinear optical substances based on the controlling parameters of open-shell character, charge and spin states

在几个真实的分子体系中，实验和理论双基特征(Y)之间存在着很强的相关性。作为一类新的开壳三阶非线性光学(NLO)分子，我们研究了(1)包括石墨烯在内的多环芳烃和(2)过渡金属-金属化合物，以阐明开壳性质与分子结构的关系以及外场、给体/受体取代基和自旋态对NLO性质的影响。在(1)中，阐明了分子结构与开壳性质之间的关系，在(2)中，揭示了原子种类和d-σ-d-σ对非线性光学性质的影响。我们与实验者合作，测量了泽仑分子的双光子吸收截面，证实了我们的理论预测。

The strong correlation between experimental and theoretical diradical characters (y) is observed for several real molecular systems. As a novel class of open-shell third-order nonlinear optical (NLO) molecules, we investigate(1) polycyclic aromatic hydrocarbons including graphenes, and(2) transition-metal-metal compounds in order to clarify the relationship between open-shell character and molecular structures as well as the effects of external field, donor/acceptor substituents and spin states on the NLO properties. In(1), the relationship between the molecular architecture and open-shell character is clarified, and in(2) the effects of atom species and dσ-dσ contributions to NLO properties are revealed. In collaboration with experimentalists, we measured the two photon absorption cross sections of zethrenes and confirmed our theoretical prediction.