Raman and IR spectroscopic studies of fenamates – Conformational differences in polymorphs of flufenamic acid, mefenamic acid and tolfenamic acid
- Resource Type
- Authors
- Babur Z. Chowdhry; Saima Jabeen; Stephen A. Leharne; Trevor J. Dines
- Source
- Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. 96:972-985
- Subject
- Models, Molecular
Spectrophotometry, Infrared
Mefenamic acid
Stereochemistry
Molecular Conformation
Infrared spectroscopy
Spectrum Analysis, Raman
Vibration
Analytical Chemistry
Mefenamic Acid
chemistry.chemical_compound
symbols.namesake
Tolfenamic acid
medicine
Molecule
ortho-Aminobenzoates
Benzene
Instrumentation
Conformational isomerism
Spectroscopy
Atomic and Molecular Physics, and Optics
Flufenamic Acid
Crystallography
Fenamates
Flufenamic acid
chemistry
symbols
Quantum Theory
Thermodynamics
Raman spectroscopy
medicine.drug
- Language
- ISSN
- 1386-1425
Solid-state Raman and IR spectra of two polymorphic forms of each of three fenamates (flufenamic acid, mefenamic acid and tolfenamic acid) display subtle but highly reproducible differences. Many of these spectral differences can be ascribed to different conformations of these molecules, involving two of four possible orientations of one substituted benzene ring with respect to the other. Interpretation of the vibrational spectra in terms of conformational differences has been facilitated by DFT calculations at the B3LYP/cc-pVDZ level for each conformer. The calculated spectra are compared with the experimental spectra in order to identify the conformers present in two polymorphic forms in each case, and detailed band assignments are obtained from the DFT calculations.