Gas-phase high-resolution molecular spectroscopy for LAV molecules

High-resolution infrared (IR) spectroscopy is essential to the analysis of molecular rotation-vibration spectra. The high-resolution spectra deliver much information about structure and dynamic of molecules, but often they are very complex. For nonrigid molecules the complexity arises from transition tunneling splittings. Methylamine is a classic example of a nonrigid molecule in which two large amplitude motions, inversion and torsion, occur simultaneously. It has six equivalent potential minima, for which an effective vibration-inversion-torsion-rotation Hamiltonian has been developed. In the chapter assignment and analysis of several spectral regions of methylamine have been briefly presented explaining the assigning techniques and theoretical treatment of experimental lines.

The full nonrigid group theory for trimethylamine

The nonrigid molecule group theory (NRG) in which the dynamical symmetry operations are defined as physical operations is a new field in chemistry. Smeyers in a series of papers applied this notion to determine the character table of restricted NRG of some molecules. In this note, a simple method is described by means of which it is possible to calculate character tables for the symmetry group of molecules consisting of a number of methyl groups attached to a rigid framework. We study the full NRG of trimethylamineN(CH3)3and prove that it is a group of order 1296 with 28 conjugacy classes. The method can be generalized to apply to other nonrigid molecules. The full nonrigid (f-NRG) molecule group theory is seen to be used advantageously to study the internal dynamics of such molecules.