Two-photon-induced excited state intramolecular proton transfer process and nonlinear optical properties of HBT in cyclohexane solution

Abstract

The two-photon-induced excited state intramolecular proton transfer (ESIPT) process of 2-(2'-hydroxyphenyl) benzothiazole (HBT) in cyclohexane solution has been investigated. We focus on the calculation of the two-photon absorption (TPA) coefficient and nonlinear refraction index of HBT, and the theoretical computational results are in good agreement with the experimental ones. By establishing the ESIPT kinetic model for HBT based on TPA, the TPA cross section is obtained. The numerical results show that HBT exhibits a rather large TPA cross section compared with that of 2-(2'-hydroxyphenyl)benzoxazole (HBO) reported previously. Therefore, HBT is a promising TPA material and is worthy of further research.