Gascooke, Jason R. published the artcileThe Case for Methyl Group Precession Accompanying Torsional Motion, COA of Formula: C2H5NO, the main research area is toluene torsional motion mol vibration.
For mols. containing a Me group, high precision fits of rotational line data (microwave spectra) that encompass several torsional states require considerably more constants than are required in comparable rigid mols. Many of these addnl. terms are ‘torsion-rotation interaction’ terms, but their precise phys. meaning is unclear. In this paper, we explore the phys. origins of many of these addnl. terms in the case where the Me group is attached to a planar frame. We show that torsion-vibration coupling, which has been observed in toluene and several substituted toluenes, provides the dominant contribution to a number of the torsion-rotation constants in toluene. It is further demonstrated that this coupling is intimately related to precession of the Me group. A number of the constants required in the high resolution fits of rotational line data are shown to arise as a natural consequence of Me precession. By considering several mols. whose rotational line spectra have been fit to high precision, we demonstrate that the exptl. evidence is consistent with the occurrence of Me group precession. Quantum chem. calculations of the optimized mol. structures at key torsional angles provide further evidence that Me precession occurs. There is both a torsional angle dependent tilt of the Cmethyl-frame bond and of the Me group principal rotation axis relative to the Cmethyl-frame bond.
Australian Journal of Chemistry published new progress about Bond angle, torsional. 123-39-7 belongs to class amides-buliding-blocks, name is N-Methylformamide, and the molecular formula is C2H5NO, COA of Formula: C2H5NO.
Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics