Computational investigation on redox-switchable nonlinear optical properties of a series of polycyclic p-quinodimethane molecules.
The polycyclic p-quinodimethanes are proposed to be the novel candidates of the high-performance nonlinear optical (NLO) materials because of their large third order polarizabilities (γ). We investigate the switchable NLO responses of a series of polycyclic p-quinodimethanes with redox properties by employing the density functional theory (DFT). The polycyclic p-quinodimethanes are forecasted to exhibit obvious pure diradical characters because of their large y 0 index (the y 0 index is a value between 0 [closed-shell state] and 1 [pure biradical state]). The γ values of these polycyclic p-quinodimethanes and their corresponding one-electron and two-electron reduced/oxidized species are calculated by the (U)BHandHLYP method. The γ values of polycyclic p-quinodimethanes and their corresponding one-electron reduced species are all positive and significantly different. The large differences of the γ values are due to a change in the transition energy and are related to the different delocalization of the spin density, which demonstrates that the NLO switching is more effective on one-electron reduction reactions. Therefore, the study on these polycyclic p-quinodimethanes provides a guideline for a molecular design of highly efficient NLO switching.
College Chemistry & Chemical Engineering, Hainan Normal University, Haikou, Hainan, 571158, People's Republic of China, qiuyq466@nenu.edu.cn.
Yong-Qing
YQ
Qiu
Wen-Yong
WY
Wang
Na-Na
NN
Ma
Cun-Huan
CH
Wang
Meng-Ying
MY
Zhang
Hai-Yan
HY
Zou
Peng-Jun
PJ
Liu