High resolution FTIR study of the ν7+ν10−ν10 and ν10+ν12−ν10 “hot” bands of C2H4

- The first high resolution analysis of the weak hot bands, v10+v12-v10 and v7+v10-v10.
- Resonance interactions in the C2H4 molecule.
- Determination of spectroscopic parameters of the (v10=v12=1) and (v7=v10=1) states.

Two weak “hot” absorption bands, ν7+ν10−ν10 and ν10+ν12−ν10, of ethylene, C2H4, were analyzed for the first time with high resolution using the Fourier transform interferometer Bruker IFS-120 HR. As the result of analysis we assigned about 930 and 370 transitions (404 and 185 upper state ro-vibrational energy values) with Jmax.=27, Kamax.=14 and Jmax.=20, Kamax.=9 for the bands ν7+ν10−ν10 and ν10+ν12−ν10, respectively. Strong local resonance interactions of the vibrational state (v10=v12=1) with the five other states, and of the state (v7=v10=1) with the seven other states were taken into account, and a set of 77 varied parameters, which reproduce the initial experimental data with the rms deviation of 6.1×10−4 cm−1 which is close to experimental uncertainties, was obtained.