Related Experiment Video
Updated: May 17, 2026

Probing the Structure and Dynamics of Interfacial Water with Scanning Tunneling Microscopy and Spectroscopy
Published on: May 27, 2018
A DFT/TDDFT study on the excited-state hydrogen bonding dynamics of 6-aminocoumarin in water solution
Mingzhen Zhang1, Baiping Ren, Yi Wang
1School of Biological Engineering, Dalian Polytechnic University, Dalian 116034, China.
Abstract:
Intermolecular hydrogen bonding, as a site-specific solute-solvent interaction, plays an extremely important role on the spectra of chemical and biological molecules. A detailed theoretical study on the hydrogen bonds is extremely necessary for understanding the unusual spectra blue-shift for some molecules. In the present paper, the hydrogen bonding dynamics of 6-aminocoumarin (6AC) in the water was investigated by the time-dependent density functional theory (TDDFT) and density functional theory (DFT) methods. According to our results, it is demonstrated that C6-N1⋯H9 bond (AHB) is the strongest hydrogen bonds among three ones formed between 6AC and water molecules in the ground state. Upon the photoexcitation, due the photo-induced charge transfer from N1 to C6, AHB is proved to be extremely weakened which is significantly greater than the strengthening of C9=O2⋯H11 bond (BHB) and N1-H6⋯O5 bond (CHB) in S1 states. This is expected to be theoretical explanation for the unusual blue-shift of a long-wavelength band in absorption spectra for 6AC in the water observed in the experiment.
More Related Videos
09:56Real-time Monitoring of Reactions Performed Using Continuous-flow Processing: The Preparation of 3-Acetylcoumarin as an Example
Published on: November 18, 2015
08:04Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
Published on: May 27, 2020
Related Concept Videos
UV–Vis Spectroscopy of Conjugated Systems
One of the factors influencing λmax is the extent of conjugation in the...
2D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)
Introduction to Chemical Bonds
The electrons of the outermost energy level determine the energetic stability of the atom and its tendency to form chemical bonds with other atoms. The innermost electron shell has a maximum capacity of two electrons, but the next two electron shells can each have a maximum of eight electrons. This is known as the octet rule, which states that, with the exception of the innermost shell, atoms are most stable energetically when they have eight electrons in their valence shell, the...
Hydrogen Bonds
Hydrogen Bonds Control the World!
Because hydrogen has very weak electronegativity when it binds with a strongly electronegative atom, such as oxygen or nitrogen, electrons in the bond are unequally shared.
Hydrogen Bonds
IR Spectrum Peak Broadening: Hydrogen Bonding
However, the extent of hydrogen bonding influences the observed stretching frequency and band broadening. Intermolecular or intramolecular hydrogen bonding...