Microwave optical double resonance of HNO: Rotational spectrum in A1A′′(100).

Rotational transitions in the ?1A″(100) state of HNO were observed using the technique of microwave optical double resonance. The HNO molecule was produced in a fast flow system by the reaction of discharged oxygen with a mixture of propylene and NO. Eighteen rotational lines observed in the frequency regions of 8 to 157 GHz and rf were analyzed to give rotational constants and centrifugal distortion constants. Perturbations were found in the K-type doubling frequencies of K−1 =1 and 2.