The infrared spectrum of doubly deuterated methane CH2D2 has been recorded in the region from 1900 to 2400 cm-1 at almost Doppler-limited resolution by using two high-resolution Fourier transform spectrometers. The vibrational bands observed include 2ν4, ν4 + ν7, 2ν7, ν2, ν8, ν4 + ν9, and ν7 + ν9, which were analyzed by taking into account Coriolis and Fermi interactions among them and also those with ν4 + ν5, ν3 + ν7, and ν5 + ν7. Most of the centrifugal distortion constants were constrained to appropriate values, while the vibrational term value and three rotational constants in each of the seven excited states were adjusted along with Coriolis and Fermi interaction parameters by the least-squares analysis of the observed spectrum. The vibration-rotation interaction constants αs thus determined for the ν2 and ν8 states were combined with those of other fundamental states already published to calculate the equilibrium C-H distance.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry