Study of resonance interactions in polyatomic molecules on the basis of highly accurate experimental data: Set of strongly interacting Bands [formula omitted], [formula omitted], [formula omitted], [formula omitted], [formula omitted] and [formula omitted] of CH2=CD2

Abstract

The highly accurate (experimental accuracy in line positions ~(1−3)×10−4cm−1) FTIR ro-vibrational spectra of CH2=CD2 in the region of 600–1300cm−1, where the fundamental bands ν10, ν7, ν4, ν8, ν3, and ν6 are located, were recorded and analyzed with the Hamiltonian model which takes into account resonance interactions between all six studied bands. About 12200 ro-vibrational transitions belonging to these bands (that is considerably more than it was made in the preceding studies for the bands ν10, ν7, ν8, ν3 and ν6; transitions belonging to the ν4 band were assigned for the first time) were assigned in the experimental spectra with the maximum values of quantum numbers Jmax./Kamax. equal to 31/20, 46/18, 33/11, 50/26, 44/20 and 42/21 for the bands ν10, ν7, ν4, ν8, ν3, and ν6, respectively. On that basis, a set of 133 vibrational, rotational, centrifugal distortion and resonance interaction parameters was obtained from the weighted fit. They reproduce values of 3920 initial “experimental” ro-vibrational energy levels (positions of about 12200 experimentally recorded and assigned transitions) with the rms error drms=2.3×10−4cm−1.