標題: | Intersystem Crossing Pathway in Quinoline-Pyrazole Isomerism: A Time-Dependent Density Functional Theory Study on Excited-State Intramolecular Proton Transfer |
作者: | Liu, Yu-Hui Lan, Sheng-Cheng Zhu, Chaoyuan Lin, Sheng-Hsien 應用化學系分子科學碩博班 Institute of Molecular science |
公開日期: | 18-六月-2015 |
摘要: | The dynamics of the excited-state intramolecular proton-transfer (ESIPT) reaction of quinoline pyrazole (QP) isomers, designated as QP-I and QP-II, has been investigated by means of time-dependent density functional theory (TDDFT). A lower barrier has been found in the potential energy curve for the lowest singlet excited state (S-1) along the proton-transfer coordinate of QP-II compared with that of QP-I; however, this is at variance with a recent experimental report [J. Phys. Chem. A 2010, 114, 7886-7891], in which the authors proposed that the ESIPT reaction would only proceed in QP-I due to the absence of a PT emission for QP-II. Therefore, several deactivating pathways have been investigated to determine whether fluorescence quenching occurs in the PT form of QP-II (PT-II). The Si state of PT-II has n pi* character, which is a well-known dark state. Moreover, the energy gap between the S-1 and T-2 states is only 0.29 eV, implying that an intersystem crossing (ISC) process would occur rapidly following the ESIPT reaction. Therefore, it is demonstrated that the ESIPT could successfully proceed in QP-II and that the PT emission would be quenched by the ISC process. |
URI: | http://dx.doi.org/10.1021/acs.jpca.5b03557 http://hdl.handle.net/11536/127886 |
ISSN: | 1089-5639 |
DOI: | 10.1021/acs.jpca.5b03557 |
期刊: | JOURNAL OF PHYSICAL CHEMISTRY A |
Volume: | 119 |
Issue: | 24 |
起始頁: | 6269 |
結束頁: | 6274 |
顯示於類別: | 期刊論文 |