Related Experiment Video
Updated: May 7, 2026

ARL Spectral Fitting as an Application to Augment Spectral Data via Franck-Condon Lineshape Analysis and Color Analysis
Published on: August 19, 2021
Solvent effect on anthranilic acid spectroscopy
Osama K Abou-Zied1, Badriya Y Al-Busaidi, John Husband
1Department of Chemistry, Faculty of Science, Sultan Qaboos University , P.O. Box 36, Postal Code 123, Muscat, Sultanate of Oman.
Anthranilic acid (AA) spectroscopy reveals its anionic form in neutral water and highlights water
Area of Science:
- Photochemistry
- Spectroscopy
- Computational Chemistry
Background:
- Anthranilic acid (AA) is a molecule with polar sites.
- Understanding solvent interactions is crucial for its photophysical properties.
Purpose of the Study:
- To investigate the spectroscopic behavior of anthranilic acid (AA) in various solvents.
- To elucidate the role of water in solvating AA's polar sites.
- To assess AA's potential as a local acidity probe.
Main Methods:
- Absorption and fluorescence spectroscopy in neat and binary solvents.
- Solvent polarity and hydrogen bonding strength analysis.
- Density functional theory (DFT) calculations for AA:water complexes.
Main Results:
- AA exists as an anion in neutral water.
- Stokes shift correlates with solvent polarity (ETN), emphasizing hydrogen bonding.
- Estimated pKa (4.50) and pKa* (4.44) values.
- Shortest fluorescence lifetime in cyclohexane attributed to intramolecular hydrogen transfer.
- Three water molecules preferentially solvate the COOH group in a cyclic geometry.
Conclusions:
- Hydrogen bonding significantly influences AA's spectral properties in solution.
- AA is suitable for probing local acidity in macromolecules within the pH range of 3.0–7.0.
More Related Videos
08:54Vibrational Spectra of a N719-Chromophore/Titania Interface from Empirical-Potential Molecular-Dynamics Simulation, Solvated by a Room Temperature Ionic Liquid
Published on: January 25, 2020
09:11Raman and IR Spectroelectrochemical Methods as Tools to Analyze Conjugated Organic Compounds
Published on: October 12, 2018
Related Concept Videos
Spectroscopy of Carboxylic Acid Derivatives
Titration in Nonaqueous Solvents
Leveling Effect
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...
Leveling Effect and Non-Aqueous Acid-Base Solutions
The Leveling Effect of a Solvent
A generic acid (HA) reacts with the generic base (B-) to yield the corresponding conjugate base (A-) and conjugate acid (HB):
Atomic Absorption Spectroscopy: Lab
Solutions containing organic solvents, such as low-molecular-mass alcohols, esters, or ketones, enhance absorbances by increasing...