Related Experiment Video
Updated: Oct 21, 2025

Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method
Published on: July 19, 2019
Ultrafast nonadiabatic excited-state intramolecular proton transfer in 3-hydroxychromone: A surface hopping approach
Probal Nag1, Neethu Anand1, Sivaranjana Reddy Vennapusa1
1School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala PO, Vithura, Thiruvananthapuram 695551, India.
Abstract:
We employ the ab initio molecular dynamics within the surface hopping method to explore the excited-state intramolecular proton transfer taking place on the coupled "bright" S1 (ππ*) and "dark" S2 (nπ*) states of 3-hydroxychromone. The nonadiabatic population transfer between these states via an accessible conical intersection would open up multiple proton transfer pathways. Our findings reveal the keto tautomer formation via S1 on a timescale similar to the O-H in-plane vibrational period (<100 fs). Structural analysis indicates that a few parameters of the five-membered proton transfer geometry that constitute the donor (hydroxyl) and acceptor (carbonyl) groups would be adequate to drive the enol to keto transformation. We also investigate the role of O-H in-plane and out-of-plane vibrational motions in the excited-state dynamics of 3-hydroxychromone.
More Related Videos
08:22Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization
Published on: August 6, 2018
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
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
UV–Vis Spectroscopy: Molecular Electronic Transitions
Chemical Shift: Internal References and Solvent Effects
The internal reference compound generally used in NMR spectroscopy is tetramethylsilane (TMS). TMS is preferred because it is chemically inert, soluble in NMR solvents, and easily removable. Also, the highly shielded methyl protons in TMS yield an intense...
Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
Nuclear Overhauser Enhancement (NOE)
Spin–Spin Coupling Constant: Overview
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...