Millimeter- and submillimeter-wave spectrum of methylene Fluoride-d(2)

The millimeter- and submillimeter-wave spectrum of methylene fluoride-d(2) (CD2F2) has been observed in the region between 200 and 415 GHz. The spectr um was recorded using a frequency-modulated millimeter- and submillimeter-w ave spectrometer. More than 400 rotational transitions up to J less than or equal to 60 and K-a less than or equal to 21 in the ground state and more than 200 rotational transitions up to J less than or equal to 48 and K-a le ss than or equal to 9 in the v(4) = 1 vibrational state have been assigned. The Lines assigned are simultaneously least-squares fitted along with the microwave data in the Watson's A- and S-reduced Hamiltonian. Improved value s have been obtained for the rotational constants and quartic centrifugal d istortion constants, including for the first time, sextic distortion consta nts of the ground state as well as the v(4) = 1 state. (C) 1999 Academic Pr ess.