The laser magnetic resonance spectrum of the ν2 band of NH2

The ν 2 fundamental band ( ν 0 = 1497.3 cm −1 ) of the NH 2 radical was studied by CO laser magnetic resonance. The NH 2 radicals were produced by the reaction of hydrated hydrazine and hydrogen atoms obtained from a discharge in water vapor. The assignment was established for about 160 Zeeman resonances which involved levels with 0 ≦ N ≦ 7 and 0 ≦ K a ≦ 5. From an analysis of the observed spectra, combined with the previously reported 10 μm and far infrared LMR spectra, the band origin, the rotational, the centrifugal distortion, and the spin-rotation constants were accurately determined both for the ν 2 = 1 and the ground states. As in the case of HCO, large changes of A , Δ K , ϵ aa , and Δ K s were observed upon the excitation of the ν 2 mode.