DIRECT MICROWAVE MEASUREMENTS OF TRANSITIONS BETWEEN l-TYPE RESONANCE DOUBLETS IN HCN AND DCN.

Abstract

Author Institution: National Bureau of Standards, Infrared \& Microwave Spectroscopy SectionThe $\Delta$ vibrational levels $(2 \nu^{2}_{2}$) of HCN and DCN are split by a rotational resonance with the nearby $\Sigma$ vibrational level $(2 \nu^{0}_{2}$). At high J values the splitting becomes large enough so that $\Delta J = 0$ transitions between $\Delta$ levels can be observed at microwave frequencies. Transitions for $J = 15$ to $J = 23$ have been observed in HCN and DCN. The agreement with calculated values will be discussed. New measurements on the usual l-doublet transitions will also be presented