Release Time:2019-03-09  Hits:

Indexed by: Journal Article

Date of Publication: 2014-02-01

Journal: CHINESE JOURNAL OF CHEMICAL PHYSICS

Included Journals: Scopus、SCIE

Volume: 27

Issue: 1

Page Number: 51-56

ISSN: 1674-0068

Key Words: Excited state intramolecular proton transfer; Intramolecular charge transfer; Time-dependent density functional theory; Dark state; Baicalein

Abstract: The excited state intramolecular proton transfer (ESIPT) coupled charge transfer of baicalein has been investigated using steady-state spectroscopic experiment and quantum chemistry calculations. The absence of the absorption peak from S-1 excited state both in the experimental and calculated absorption spectra indicates that S-1 is a dark state. The dark excited state S-1 results in the very weak fluorescence of solid baicalein in the experiment. The frontier molecular orbital and the charge difference densities of baicalein show clearly that the S-1 state is a charge-transfer state whereas the S-2 state is a locally excited state. The only one stationary point on the potential energy profile of excited state suggests that the ESIPT reaction of baicalein is a barrierless process.