Terahertz and infrared spectra of carbonyl fluoride, COF2: Vibration-rotation analyses of the four lowest bands, 2ν6, and ν6 hot bands; 13COF2 ground state and ν6 band

The rotational spectrum of COF2 has been observed near 1, 1.6 and 2.5 THz as part of a continuing program to precisely characterize the spectra of atmospheric molecules. THz spectra of the ground, ν2, ν3, ν5, and ν6 states have been assigned, combined with other available rotational data and high resolution infrared data, and fit in a single calculation up to J≈90 for a wide range of Kc. Watson IIIlS or IrA parameters produce fits of essentially the same quality. A preliminary fit of the 2ν6 band is also reported as well as all hot bands in the ν6 region which originate in the states below 1000 cm−1. The THz rotational spectrum of naturally abundant 13COF2 in its ground vibrational state has also been observed and fit separately as has the infrared spectrum of its ν6 band. These results provide more accurate prediction of high J rotational spectra and infrared spectra of the fundamental vibrations below 1000cm−1.

► New measurements of COF2 near 1.0, 1.6 and 2.5 THz. ► Global fits of rotational and infrared data for the ground, ν2, ν3, ν5, and ν6 states. ► The first fits for ν6 hot bands originating in ν2, ν3, ν5, and ν6 states. ► Assignment and fit for the 2ν6 overtone. ► New measurements and fits for 13COF2 rotational and ν6 spectra.