Related Experiment Video
Updated: Aug 6, 2026

Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy
Published on: June 27, 2014
Time-Resolved X-ray Photoelectron Spectroscopy: Probing Bond Order Rearrangements during Ultrafast Excited-State
Victor M Freixas1, Axel Gomez2, Yonghao Gu1
1Department of Chemistry, Department of Physics and Astronomy, University of California, Irvine, California92697, United States.
Abstract:
Excited-state intramolecular proton transfer (ESIPT) provides a minimal yet rich framework for studying bond order rearrangements during chemical reactions. Here we combine linear-response time-dependent density functional theory (TDDFT), ab initio molecular dynamics, and neural network potentials including nuclear quantum effects, to compute time-resolved X-ray photoelectron spectroscopy (tr-XPS) during ESIPT in 10-hydroxybenzo[h]quinoline (HBQ) and its deuterated analog (DBQ). By tuning the photoionization probe energy, site-specific sensitivity is achieved through selective ionization of core electrons from either the donor O atom or the acceptor N atom. The tr-XPS signal exhibits a strong dependence on ESIPT through changes in photoelectron yield and binding energy. Differences in ESIPT time scales and isotope-dependent oscillatory spectral features between HBQ and DBQ enable direct connections to local bond order rearrangements near the probed X-ray chromophores. These results demonstrate that tr-XPS provides a powerful site-specific probe of ESIPT and the associated dynamics through its sensitivity to local charge redistribution that governs bond-order rearrangements, highlighting its potential for future experimental realization.
More Related Videos
Related Concept Videos
Fast Reactions
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
Double Resonance Techniques: Overview
Spin decoupling is usually achieved by...
UV–Vis Spectroscopy: Molecular Electronic Transitions
¹H NMR: Complex Splitting
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied first.

