Related Experiment Video
Updated: May 10, 2026

Raman and IR Spectroelectrochemical Methods as Tools to Analyze Conjugated Organic Compounds
Published on: October 12, 2018
Experimental and theoretical FTIR and FT-Raman spectroscopic analysis of 1-pyrenecarboxylic acid
1Department of Mechatronics Engineering, HFT Technology Faculty, Celal Bayar University, 45400 Turgutlu, Manisa, Turkey.
Abstract:
The title molecule 1-pyrenecarboxylic acid (1PCA) has been characterized by FTIR, FT-Raman, NMR and UV-Vis spectral analyses. The molecular geometry, harmonic vibrational modes, the corresponding wavenumbers and IR intensities of 1PCA were calculated by DFT method with 6-311G(d,p) basis set. The assignments of the fundamentals were proposed on the basis of total energy distribution (TED) calculations. The calculated (13)C and (1)H NMR chemical shifts using gauge including atomic orbitals (GIAOs) approach are in good agreement with the observed chemical shifts. The polarizability and first order hyperpolarizability of the title molecule were calculated and interpreted. Using TD-DFT method, the electronic transitions have been compared with the experimental wavelengths. The molecular electrostatic potential map was used for prediction of possible hydrogen and oxygen bonding sites 1PCA molecule.
Related Concept Videos
Spectroscopy of Carboxylic Acid Derivatives
In the...
IR and UV–Vis Spectroscopy of Carboxylic Acids
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, 1710 cm−1. The C=O bond of the...
NMR and Mass Spectroscopy of Carboxylic Acids
While α protons of carboxylic acids absorb at 2–2.5 ppm, β protons absorb further upfield.
Carboxylic acids are easily identified by dissolving them in deuterium oxide, which results in a rapid exchange of the acidic protons with deuterium. This leads to the disappearance of the acidic...
Raman Spectroscopy: Overview
However, a small fraction of the scattered light exhibits a frequency shift due to the exchange of energy between the incident photons and the...
Physical Properties of Carboxylic Acid Derivatives
Among the carboxylic acid derivatives, the boiling points of acid chlorides and esters are very similar and are the lowest in the series. Acid anhydrides have slightly higher boiling...
Physical Properties of Carboxylic Acids

