Related Experiment Video
Updated: Sep 26, 2025
09:56
Real-time Monitoring of Reactions Performed Using Continuous-flow Processing: The Preparation of 3-Acetylcoumarin as an Example
Published on: November 18, 2015
9.8K
Coumarin 343 in aqueous solution: theoretical analysis of absorption
Evgeniy S Savenko1, Victor V Kostjukov2
1Physics Department, Sevastopol State University, Universitetskaya St., 33, Sevastopol, 299053, Crimea.
Journal of Molecular Modeling
|April 23, 2022
Summary
This study accurately predicts coumarin C343 absorption spectra using computational methods, considering vibronic coupling and hydration effects in water. Results reveal localized electron density shifts upon excitation, not a full molecular charge transfer.
Area of Science:
- Computational Chemistry
- Spectroscopy
- Physical Chemistry
Background:
- Understanding the photophysical properties of coumarin dyes is crucial for various applications.
- The influence of solvent and molecular structure on absorption spectra requires detailed investigation.
Purpose of the Study:
- To theoretically model and analyze the vibronic absorption spectra of coumarin C343 in aqueous media.
- To investigate the structural and electronic differences between neutral and anionic coumarin C343.
- To elucidate the role of hydration on the spectral properties of coumarin C343.
Main Methods:
- Utilized the B3LYP functional with the 6-31++G(d,p) basis set for electronic structure calculations.
- Employed the IEF-PCM solvent continuum model to simulate aqueous environments.
- Calculated theoretical vibronic absorption spectra and compared them with experimental data.
Main Results:
- Achieved excellent agreement between theoretical and experimental vibronic absorption spectra for coumarin C343.
- Identified distinct structural differences, including carboxyl group twisting, between neutral (C3430) and anionic (C343-) forms.
- Observed localized electron density shifts from C10 to C4 upon excitation, indicating no overall molecular charge transfer.
Conclusions:
- The chosen computational approach accurately reproduces experimental vibronic absorption spectra of coumarin C343 in water.
- Hydration and vibronic coupling are significant factors influencing the spectral characteristics of coumarin C343.
- Excitation leads to localized electronic rearrangements rather than global charge transfer within the coumarin C343 molecule.
More Related Videos
Related Concept Videos
01:32UV–Vis Spectroscopy of Conjugated Systems
7.4K
Organic compounds with conjugated double bonds show strong absorption features in the UV–visible region of the electromagnetic spectrum attributed to π → π* electronic excitations. Generally, a UV–vis absorption spectrum is recorded as a plot of absorbance vs wavelength. The wavelength of maximum absorbance, which manifests as a peak in the absorption spectrum, is denoted as λmax.
One of the factors influencing λmax is the extent...
One of the factors influencing λmax is the extent...
7.4K
01:16Methods for Studying Drug Absorption: In vitro
354
In vitro experiments are crucial for understanding the transport and absorption of drugs through biological materials. These studies employ varied methods such as the diffusion cell method, the everted sac technique, and the everted ring technique.
The diffusion cell method uses a two-compartment cell, including a donor compartment with the drug solution, which simulates the environment where the drug is applied, and a receptor compartment with a buffer solution, which simulates the environment...
The diffusion cell method uses a two-compartment cell, including a donor compartment with the drug solution, which simulates the environment where the drug is applied, and a receptor compartment with a buffer solution, which simulates the environment...
354
01:09Methods for Studying Drug Absorption: In situ
374
In situ experiments, such as the Doluisio method and Single-Pass Perfusion technique, provide critical insights into drug uptake by simulating in vivo conditions for drug absorption.
The Doluisio method involves perfusing a prepared segment of a rat's small intestine with a solution of radiolabeled drug and a non-absorbable marker. This helps to differentiate between absorbed and non-absorbed drug concentrations. The intestinal segment is connected at both ends using tubing and syringes,...
The Doluisio method involves perfusing a prepared segment of a rat's small intestine with a solution of radiolabeled drug and a non-absorbable marker. This helps to differentiate between absorbed and non-absorbed drug concentrations. The intestinal segment is connected at both ends using tubing and syringes,...
374
01:28IR and UV–Vis Spectroscopy of Carboxylic Acids
4.6K
In IR spectroscopy of carboxylic acids, the C=O bond shows a characteristic band between 1710 and 1760 cm⁻¹, and the O–H bond exhibits a broad band between 2500 and 3300 cm⁻¹.
However, the stretching absorptions for the C=O bond vary depending on the structure of carboxylic acids. The C=O bond of the free carboxylic acids shows a higher stretching frequency, 1760 cm−1, while H-bonded carboxylic acids (dimers) exhibit stretching absorptions at a lower frequency,...
However, the stretching absorptions for the C=O bond vary depending on the structure of carboxylic acids. The C=O bond of the free carboxylic acids shows a higher stretching frequency, 1760 cm−1, while H-bonded carboxylic acids (dimers) exhibit stretching absorptions at a lower frequency,...
4.6K
01:30UV–Vis Spectrum
1.4K
When light passes through a substance, a portion of the light is absorbed while the remaining light is reflected or transmitted. If the molecule absorbs light between the wavelengths of 180–400 nm range, the UV spectrum is obtained, and if it absorbs light in the 400–780 nm wavelength range, the visible spectrum is obtained.
The UV–Vis spectrum of a molecule is the plot of its absorbance versus wavelength. The plot is drawn by taking molar...
The UV–Vis spectrum of a molecule is the plot of its absorbance versus wavelength. The plot is drawn by taking molar...
1.4K
01:00Coulometry: Overview
1.7K
Coulometry is one of the rapid, most accurate, and precise analytical techniques that determine the quantity of an analyte by measuring the electrical charge needed for its complete electrolysis without using any analytical standards. The total charge passed during electrolysis correlates with the analyte amount by Faraday's laws of electrolysis. For accurate coulometric measurements, a charge equal to Faraday's constant multiplied by the number of electrons involved in the relevant...
1.7K