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Indexed by:期刊论文

Date of Publication:2014-01-01

Journal:RSC ADVANCES

Included Journals:SCIE、EI、Scopus

Volume:4

Issue:51

Page Number:27078-27083

ISSN No.:2046-2069

Abstract:The excited-state proton transfer (ESPT) behavior of 4-hydroxybenzoic acid is studied by means of steadystate spectroscopy and theoretical calculations to obtain insight of the excited state dynamics. The large Stokes shift for 4-hydroxybenzoate (4HB) at the pH value of the microenvironment of 6.74 indicates that the ESPT process took place. The proton transfer dynamics of the water-bridged complexes, 4HB center dot (H2O)(x), with two different water chain lengths is investigated using density functional theory and time-dependent density functional theory. The constructed potential energy curves among the optimized 4HB center dot (H2O)(x) (enol form) and 4KB center dot (H2O)(x) (keto form) geometries at the ground and the first singlet excited state indicate that the ESPT indeed occurs as the barrier is less than 10 kcal mol(-1). In addition, the driving force is confirmed by NBO population analysis.