Related Experiment Video
Updated: Sep 11, 2025

Spatial Separation of Molecular Conformers and Clusters
Published on: January 9, 2014
Changes in the Conformational Preference of Benzyl Methyl Ether upon Hydrogen Bonding
Yuji Yamada1, Kohei Nishizono1, Shizuka Okajima1
1Department of Chemistry, Graduate School of Science, Fukuoka University, Jonan-ku, Fukuoka 814-0180, Japan.
None:
The effect of hydrogen bonding (H-bonding) on the conformational preference of benzyl methyl ether (BME) has been investigated by obtaining conformer-selected infrared (IR) spectra of BME-(H2O)1 and BME-(CH3OH)1,2 clusters in a supersonic jet. The results of quantum chemical calculations were consistent with the experimental observations, revealing the coexistence of two conformers with different CCOC dihedral angles in the BME-(H2O)1 and BME-(CH3OH)1 clusters, with the BME moiety acting as an OH···O H-bond acceptor. Because the observed CH stretching bands were similar to those of the three isomers of bare BME, these two clusters were classified as the gauche and trans conformers. Conversely, only one BME-(CH3OH)2 isomer was observed, consisting of the trans conformer with a chain-type H-bonding network starting from the CH group of the side chain. This difference in conformational preference, namely, three isomers of the monomer, two conformers in monosolvated clusters, and only one BME-(CH3OH)2 isomer, was attributed to an additional CH···O H-bond forming a chain-like network and a secondary OH/CH···π interaction between solvent molecules and the benzene ring. The H-bond-accepting ability of BME was compared to those of several oxygen-containing aromatic molecules by comparing the red shift of the OH stretching bands attributed to H-bonded water and methanol. Because of the correlation between these redshifts and the natural bond orbital (NBO) analysis results, the reduced H-bond-accepting ability was ascribed to electron delocalization from the nonbonding orbital of the oxygen atom via aromaticity.
Related Concept Videos
Conformations of Ethane and Propane
Staggered conformation is a low energy and more stable conformation with the C-H bonds on the front carbon placed at 60°dihedral angles relative to the C-H bonds on the back carbon, leading to a reduced torsional strain. In staggered...
NMR Spectroscopy of Benzene Derivatives
Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
Inductive Effects on Chemical Shift: Overview
Structure of Benzene: Molecular Orbital Model
Conformations of Butane

