Related Experiment Video
Updated: Jun 13, 2026

Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method
Published on: July 19, 2019
Excited state intramolecular proton transfer and charge transfer dynamics of a 2-(2'-hydroxyphenyl)benzoxazole
Chul Hoon Kim1, Jaehun Park, Jangwon Seo
1Department of Chemistry, Pohang University of Science and Technology, Pohang, 790-784, Korea. ketone@postech.ac.kr
Abstract:
Excited state intramolecular proton transfer (ESIPT) and subsequent intramolecular charge transfer (ICT) dynamics of a 2-(2'-hydroxyphenyl)benzoxazole derivative conjugated with an electron withdrawing group (HBOCE) in solutions and a polymer film has been investigated by femtosecond time-resolved fluorescence (TRF) and TRF spectra measurements without the conventional spectral reconstruction method. TRF with high enough resolution (<100 fs) reveals that the ESIPT dynamics of HBOCE in liquids proceeds by at least two time constants of approximately 250 fs and approximately 1.2 ps. The relative amplitude of the slower picosecond component is smaller in the polymer film than that in solution. Conformational heterogeneity in the ground state originating from the dispersion of the dihedral angle between the phenolic and benzoxazole groups is invoked to account for the dispersive ESIPT dynamics in liquids. From the TRF spectra of both the enol and keto isomers, we have identified the ICT reaction of the keto isomer occurring subsequent to the ESIPT. The ICT proceeds also by two time constants of near instantaneous and 2.7 ps. Since the ICT dynamics of HBOCE is rather close to the polar solvation dynamics, we argue that the ICT is barrierless and determined mostly by the solvent fluctuation.
More Related Videos
10:21Developing Photosensitizer-Cobaloxime Hybrids for Solar-Driven H2 Production in Aqueous Aerobic Conditions
Published on: October 5, 2019
10:03Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy
Published on: June 27, 2014
Related Concept Videos
NMR Spectroscopy of Benzene Derivatives
Hydrolysis of Chlorobenzene to Phenol: Dow Process
Oxidation of Phenols to Quinones
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox property is crucial in...
Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
Aromatic Hydrocarbon Cations: Structural Overview
Removing one hydrogen from the intervening CH2 group with both...
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3