Related Experiment Video
Updated: Aug 22, 2025

Spatial Separation of Molecular Conformers and Clusters
Published on: January 9, 2014
Solvent-polarity-dependent conformation and ESIPT behaviors for 2-(benzimidazol-2-yl)-3-hydroxychromone: a novel
Jinfeng Zhao1,2, Bing Jin2, Zhe Tang2,3
1College of Physical Science and Technology, Shenyang Normal University, Shenyang, 110034, China. jfzhao1990112@163.com.
Abstract:
In view of the potential importance of 3-hydroxychromone derivatives, in this work, we mainly focused on exploring the solvent-polarity-dependent photoinduced behaviors of 2-(benzimidazol-2-yl)-3-hydroxychromone (BI3HC). Distinguished from previous work, we first checked the coexisting three conformations (i.e., BI3HC-A, BI3HC-B, and BI3HC-C) and the presence of a coexistence mechanism between BI3HC-A and BI3HC-C. Most importantly, BI3HC-A is the main component in non-polar solvents, while BI3HC-C is the main one in polar solvents. Through combined analysis of the infrared (IR) vibrational spectra and geometrical variations as well as predicted hydrogen bonding energy via the bond critical point (BCP) between S0 and S1 states, we present a hydrogen bonding strengthening phenomenon that facilitates the excited-state intramolecular proton-transfer (ESIPT) behavior for BI3HC-A and BI3HC-C. To qualitatively investigate photoinduced behaviors based on frontier molecular orbitals (MOs), we found that photoinduced intramolecular charge transfer (ICT) and charge redistribution promoted an ESIPT tendency. By comparing the barriers of the potential energy curves (PECs) between twisting dihedral angles and ESIPT paths, we could rule out mutual transformations in the S1 state and also propose a solvent-polarity-regulated ESIPT behavior for BI3HC-A and BI3HC-C. Furthermore, via searching the transition state (TS) and performing intrinsic reaction coordinate (IRC) simulations, we further checked the ESIPT mechanism. Through gaining insights in spectral variations in solvents, we uncovered the solvent-polarity-dependent spectral behaviors. We sincerely hope this work will not only help clarify the solvent-polarity-regulated dynamical behaviors of BI3HC but also pave the way for further explorations and applications of other 3-hydroxychromone derivatives.
More Related Videos
Related Concept Videos
Stereoisomerism of Cyclic Compounds
Stability of Substituted Cyclohexanes
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
Prochirality
Conformations of Cyclohexane
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal...
Stereoisomerism
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
SN2 Reaction: Stereochemistry
If the substrate is an achiral molecule at the α-carbon, the inversion of configuration is not...
![Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60786.jpg&w=3840&q=50)
