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论文类型：期刊论文

发表时间：2010-08-01

发表刊物：JOURNAL OF LUMINESCENCE

收录刊物：SCIE、EI、Scopus

卷号：130

期号：8

页面范围：1431-1436

ISSN号：0022-2313

关键字：Excited state intramolecular proton transfer; Hydrogen bonding; Proton transfer tautomer; 3-Hydroxy-2-(pyridin-2-yl)-4H-chromen-4-one

摘要：The time-dependent density functional theory (TDDFT) method was carried out to investigate the excited state intramolecular proton transfer (ESIPT) process of 3-hydroxy-2-(pyridin-2-yl)-4H-chromen-4-one (1a). 1a has two tautomeric forms: one is 1a(O), which is induced by intramolecular hydrogen bond O-H center dot center dot center dot O=C, and the other one is 1a(N), which is caused by intramolecular hydrogen bond O-H center dot center dot center dot N. From excited state to tautomer excited state coming from ESIPT, the hydroxyl hydrogen breaks away and the dissociated hydrogen adsorbed on pyridinic nitrogen or carbonyl oxygen formed new intramolecular HB and the corresponding bond length and bond angle varied greatly. In comparison, a similar process of proton transfer for 1a(N)H(+). protonated 1a(N) from ground state to excited state was obtained. This detailed proton transfer mechanism was provided by molecular orbitals analysis and it may be applied to molecular switch and organic Lewis acid/base. We investigated the excited state proton transfer mechanism of the four molecules through the theoretical method for the first time and gave unambiguous geometry of excited state. (C) 2010 Elsevier B.V. All rights reserved.