Study of the high resolution FTIR spectrum of CH2CD2 in the region of 1300-1450 cm−1: The ν12(A1) and 2ν10(A1) bands

- Ro-vibrational spectra of CH2CD2.
- The first high resolution analysis of the 2ν10 band.
- Resonance interactions in the CH2CD2 molecule.
- Determination of spectroscopic parameters.

The high resolution IR spectrum of the CH2CD2 ethylene isotopomer was recorded and analyzed in the region of 1300-1450 cm−1, where the strongly interacting bands ν12(A1) and 2ν10(A1) are located (the band ν12 was analyzed earlier; transitions belonging to the 2ν10 band were experimentally recorded and assigned in the present study for the first time). For description of the upper ro-vibrational energy levels obtained from the assigned transitions, the used Hamiltonian takes into account not only resonance interactions between the states (v12=1) and (v10=2), but interactions of the mentioned pair of vibrational states with the states (v7=v10=1) and (v7=2), as well. More than 1960 and 320 transitions with the values Jmax.=48/Kamax.=20 and Jmax.=24/Kamax.=7 were assigned to the bands ν12(A1) and 2ν10(A1), respectively. A set of 59 spectroscopic parameters was obtained from a weighted least square fit procedure. This reproduces the 959 and 180 initial upper ro-vibrational energies of the vibrational states ν12(A1) and 2ν10(A1) used in the fit with a drms=1.7×10−4cm−1 and drms=2.2×10−4cm−1, respectively (in this case, only upper energies obtained from unblended and nonsaturated transitions of relatively high intensities have been taken into account). The ground state rotational parameters were improved in comparison with the parameters known in the literature.