High resolution ro-vibrational analysis of interacting bands ν4, ν7, ν10, and ν12 of 13C2H4

Abstract

High accurate, ~1×10−4cm−1, ro-vibrational spectra of the C213H4 molecule in the region of 600–1600cm−1 were recorded with Bruker IFS 120/125 HR Fourier transform interferometers and analyzed in the Hamiltonian model which takes into account Coriolis resonance interactions between all four bands. More than 660, 3870, 2420, and 2550 transitions belonging to the ν4, ν7, ν10, and ν12 bands were assigned in the experimental spectrum with the maximum values of quantum numbers Jmax./Kamax., equal to 38/10, 43/21, 33/16 and 52/18, respectively. To make the ro-vibrational analysis physically more suitable, the initial values of the rotational and centrifugal distortion parameters of the studied bands were theoretically estimated by the use of isotopic relations. On that basis, a set of 55 vibrational, rotational, centrifugal distortion, and resonance interaction parameters was obtained from the fit. They reproduce values of 2934 initial “experimental” ro-vibrational energy levels obtained from nonsaturated unblended lines (more than 9500 assigned transitions of the ν4, ν7, ν10, and ν12 bands) with the rms error drms=0.00014cm−1. Ground state parameters of the C213H4 molecule were improved as well.