Related Experiment Video
Updated: Sep 11, 2025

Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy
Published on: June 27, 2014
Long-range proton transfer mechanism and fluorescence properties of HQBT chromophore: TD-DFT/CASSCF study
Zuzhi Chen1, Yingrui Yin1, Nannan Cheng1
1State Key Laboratory of Metastable Materials Science and Technology and Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao 066004, People's Republic of China.
Abstract:
Herein, the intramolecular long-range proton transfer reaction mechanism of the HQBT chromophore in different solvents is investigated employing density functional theory and complete active space self-consistent field methods. The results show that HQBT successfully undergoes the first excited state intramolecular proton transfer (ESIPT) under photoexcitation. Subsequently, through the first cis-trans isomerization process of dihedral angle torsion, a minimum energy conical intersection (MECI) is formed between the ground state and the first excited state. The MECI continues the second cis-trans isomerization to generate the trans-keto structure. At this point, a new intramolecular hydrogen bond is formed and experiences the second ESIPT, thus achieving long-range transport of hydrogen protons. This careful theoretical research has significant guiding significance for the design of intelligent and efficient tautomeric molecular switches in the future.
More Related Videos
Related Concept Videos
Protein Dynamics in Living Cells
Fluorescent recovery after photobleaching (FRAP) is a fluorescent-protein-based detection technique used to quantify protein movement rates within the cell. This method exposes a small portion of the cell to an intense laser beam. The laser beam causes permanent photobleaching of the fluorophore-tagged proteins in the exposed region. As the bleached...
2D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)
2D NMR: Overview of Heteronuclear Correlation Techniques
Variables Affecting Phosphorescence and Fluorescence
¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)

