基于4-氨基-1,8萘酰亚胺的双光子荧光H_2S探针光学性质与响应机理分析

Optical Properties and Responsive Mechanism of 4-Amino-1,8-Naphthalimide-Based Two-Photon Fluorescent Probe for Sensing Hydrogen Sulfide

基于密度泛函理论水平上的解析响应函数方法,采用极化连续模型(PCM)研究了两种新型的截断型双光子荧光H_2S探针AcHS-1,2的单双光子吸收及荧光发射性质,并对其响应机制进行了理论分析.计算结果表明,AcHS-1,2在与H_2S反应后,生成物的单双光子吸收性质特别是荧光发射性质发生了明显的变化,它们的吸收峰都有较大的红移.此外,不同末端基团对探针分子的光学性质也有一定的影响.分析了探针分子AcHS-1,2与H_2S反应前后的Mulliken布居及电荷转移过程,反应后分子内电荷转移量增大,从而改变了分子的光学性质,实现了对H_2S的探测.

Response theory was used to investigate one-photon absorption （OPA） and emission, and two- photon absorption （TPA） of two novel truncated two-photon fluorescent probes AcHS-1,2 in the presence and absence of H2S using density functional theory in combination with the polarizable continuum model. Changes in the optical properties, including large redshifts of the OPA, TPA, and emission peak positions were observed when the probes reacted with H2S, indicating that AcHS-1,2 make effective and selective chemosensors for H^S. We have also demonstrated that the terminal group on the probes influenced their nonlinear optical properties （AcHS-I： n-butyl group and AcHS-2： hydroxyethyl group）. The responsive mechanism of AcHS-1,2 for sensing H2S was analyzed by studying the charge variations between the charge transfer and ground states of the free molecules and their reaction products using Mulliken population analysis. Importantly, this mechanism was attributed to an intramolecular charge transfer.