A DFT/TD-DFT study of effect of different substituent on ESIPT fluorescence features of 2-(2’-hydroxyphenyl)-4-chloromethylthiazole derivatives  

作　　者：Shen-Yang Su Xiu-Ning Liang Hua Fang 苏申阳;梁秀宁;方华(Department of Chemistry and Material Science,College of Science,Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]Department of Chemistry and Material Science,College of Science,Nanjing Forestry University,Nanjing 210037,China

出　　处：《Chinese Physics B》2022年第3期589-596,共8页中国物理B（英文版）

摘　　要：Based on density functional theory(DFT) and time-dependent density functional theory(TD-DFT), the effects of substituent on the excited-state intramolecular proton transfer(ESIPT) process and photophysical properties of 2-(2’-hydroxyphenyl)-4-chloromethylthiazole(HCT) are studied. The electron-donating group(CH_(3), OH) and electronwithdrawing group(CF_(3), CHO) are introduced to analyze the changes of intramolecular H-bond, the frontier molecular orbitals, the absorption/fluorescence spectra, and the energy barrier of ESIPT process. The calculation results indicate that electron-donating group strengthens the intramolecular H-bond in the S_(1) state, and leads to an easier ESIPT process. The electron-withdrawing group weakens the corresponding H-bond and makes ESIPT process a little harder. Different substituents also affect the photophysical properties of HCT. The electron-withdrawing group(CF_(3), CHO) has a little effect on electronic spectra. The electron-donating group(CH_(3), OH) red-shifts both the absorption and fluorescence emission peaks of HCT, respectively, which causes the Stokes shift to increase.

关 键 词：excited-state intramolecular proton transfer(ESIPT) TD-DFT SUBSTITUTION 

分 类 号：O626[理学—有机化学] O641.1[理学—化学]