Excited-state intermolecular proton transfer and competing pathways in 3-hydroxychromone: a non-adiabatic dynamics
Alessandro Nicola Nardi1, Morgane Vacher1
1Nantes Université, CNRS, CEISAM, UMR 6230, Nantes F-44000, France. morgane.vacher@univ-nantes.fr.
Physical Chemistry Chemical Physics : PCCP
|February 5, 2026
Summary
Excited-state intramolecular proton transfer (ESIPT) in 3-hydroxychromone shows two time scales. A novel study reveals a torsional motion explains the slower ESIPT component, clarifying photochemical dynamics.
Area of Science:
- Photochemistry
- Chemical Physics
- Molecular Dynamics
Background:
- Excited-state intramolecular proton transfer (ESIPT) is a key photochemical process.
- 3-hydroxychromone (3-HC) exhibits dual ESIPT time scales (femtosecond and picosecond).
- The origin of the slower picosecond ESIPT component in 3-HC remains mechanistically unclear.
Purpose of the Study:
- To elucidate the microscopic origin of the dual ESIPT time scales in 3-hydroxychromone.
- To investigate the interplay between direct ESIPT and other excited-state dynamics.
- To develop a comprehensive mechanistic framework for 3-HC's non-adiabatic excited-state behavior.
Main Methods:
- Mixed quantum-classical non-adiabatic dynamics simulations.
- Analysis of excited-state potential energy surfaces.
- Examination of non-adiabatic trajectories.
Main Results:
- Explicit observation of both ultrafast (femtosecond) and slower (picosecond) ESIPT time constants.
- Rationalization of the slower ESIPT component by a competitive out-of-plane hydrogen torsional motion.
- Construction of a reaction network detailing direct ESIPT and torsion-mediated pathways.
Conclusions:
- The study provides a unified mechanistic framework reconciling dual ESIPT time scales in 3-HC.
- Out-of-plane hydrogen torsional motion is identified as the origin of the slower ESIPT component.
- New insights into the non-adiabatic excited-state dynamics of ESIPT systems are offered.
Related Concept Videos
02:28Intermolecular Forces in Solutions
39.7K
The formation of a solution is an example of a spontaneous process, a process that occurs under specified conditions without energy from some external source.
When the strengths of the intermolecular forces of attraction between solute and solvent species in a solution are no different than those present in the separated components, the solution is formed with no accompanying energy change. Such a solution is called an ideal solution. A mixture of ideal gases (or gases such as helium and argon,...
When the strengths of the intermolecular forces of attraction between solute and solvent species in a solution are no different than those present in the separated components, the solution is formed with no accompanying energy change. Such a solution is called an ideal solution. A mixture of ideal gases (or gases such as helium and argon,...
39.7K
03:13Intermolecular Forces
71.5K
Atoms and molecules interact through bonds (or forces): intramolecular and intermolecular. The forces are electrostatic as they arise from interactions (attractive or repulsive) between charged species (permanent, partial, or temporary charges) and exist with varying strengths between ions, polar, nonpolar, and neutral molecules. The different types of intermolecular forces are ion–dipole, dipole–dipole, hydrogen bonds, and dispersion; among these, dipole–dipole, hydrogen...
71.5K
03:00Intermolecular vs Intramolecular Forces
97.4K
Intermolecular forces (IMF) are electrostatic attractions arising from charge-charge interactions between molecules. The strength of the intermolecular force is influenced by the distance of separation between molecules. The forces significantly affect the interactions in solids and liquids, where the molecules are close together. In gases, IMFs become important only under high-pressure conditions (due to the proximity of gas molecules). Intermolecular forces dictate the physical properties of...
97.4K
02:34Comparing Intermolecular Forces: Melting Point, Boiling Point, and Miscibility
51.6K
Intermolecular forces are attractive forces that exist between molecules. They dictate several bulk properties, such as melting points, boiling points, and solubilities (miscibilities) of substances. Molar mass, molecular shape, and polarity affect the strength of different intermolecular forces, which influence the magnitude of physical properties across a family of molecules.
Temporary attractive forces like dispersion are present in all molecules, whether they are polar or nonpolar. They...
Temporary attractive forces like dispersion are present in all molecules, whether they are polar or nonpolar. They...
51.6K
01:20Work Done in an Adiabatic Process
4.3K
Consider the adiabatic compression of an ideal gas in the cylinder of an automobile diesel engine. The gasoline vapor is injected into the cylinder of an automobile engine when the piston is in its expanded position. The temperature, pressure, and volume of the resulting gas-air mixture are 20 °C, 1.00 x 105 N/m2, and 240 cm3 , respectively. The mixture is then compressed adiabatically to a volume of 40 cm3. Note that, in the actual operation of an automobile engine, the compression is not...
4.3K
02:56Intermolecular Forces and Physical Properties
27.6K
27.6K