MILLIMETER WAVE SPECTRUM OF CYANAMIDE

Abstract

Millimeter wave frequency measurements have been obtained for transitions of cyanamide molecule $(NH_{2}CN)$ in the ground state and the lowest vibrational $(NH_{2}$ inversion) state, extending the measured spectrum of the molecule to 120 GHz. Perturbations resulting from Coriolis type interactions between the ground and the lowest vibrational state cause many of the observed transitions to deviate significantly from the predictions of a conventional centrifugal distortion corrected rigid rotor model. From this investigation the lowest vibrational $(NH_{2}$ inversion) frequency was found to be $49.2 \pm 1.0 cm^{-1}$. The laboratory rest frequencies of the $4_{13}~^{-3}12$ and $5_{14}$ $-4_{13}$ transitions of the ground state confirm the previous assignment of these transitions in the interstellar $medium.^{1}$