Related Experiment Video
Updated: Mar 26, 2026

Analyzing the Photo-oxidation of 2-propanol at Indoor Air Level Concentrations Using Field Asymmetric Ion Mobility Spectrometry
Published on: June 14, 2018
Aminophenol isomers unraveled by conformer-specific far-IR action spectroscopy
Vasyl Yatsyna1, Daniël J Bakker2, Raimund Feifel3
1University of Gothenburg, Department of Physics, 412 96 Gotheburg, Sweden. vitali.zhaunerchyk@physics.gu.se and Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernoovield 7-c, 6525 ED Nijmegen, The Netherlands. a.rijs@science.ru.nl.
Abstract:
Spectroscopic studies of molecular structure can strongly benefit from extending the conventional mid-IR range to the far-IR and THz regions, as low-frequency molecular vibrations provide unique fingerprints and high sensitivity to intra- and intermolecular interactions. In this work, the gas-phase conformer specific far-IR spectra of aminophenol isomers, recorded in the spectral range of 220-800 cm(-1) at the free-electron laser laboratory FELIX in Nijmegen (the Netherlands), are reported. Many distinct far-IR vibrational signatures which are specific for the molecular structure of the different aminophenol isomers are revealed and assigned. The observed far-IR transitions of the NH2 wagging (inversion) motion have been treated with a double-minimum harmonic well potential model that has enabled us to obtain the inversion barrier values. Moreover, we discuss the limitations and capability of conventional DFT frequency calculations to describe the far-IR vibrational modes.
Related Concept Videos
IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations
IR Spectroscopy: Molecular Vibration Overview
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
IR and UV–Vis Spectroscopy of Aldehydes and Ketones
¹H NMR Chemical Shift Equivalence: Enantiotopic and Diastereotopic Protons
In chiral compounds such as 2-butanol, replacing the methylene hydrogens at C3 produces a pair of...
IR Spectrum Peak Broadening: Hydrogen Bonding
However, the extent of hydrogen bonding influences the observed stretching frequency and band broadening. Intermolecular or intramolecular...

