The OH stretching fundamental of hydroxylamine

The OH stretching fundamental of hydroxylamine, ν₁, has been studied using a computer-controlled color center laser spectrometer. Absorption and Stark-modulated spectra of this AC hybrid band were obtained in the spectral region from 3630 to 3710 cm^?1. The spectrum is dominated by many strong perpendicular c-type Q branches, but both parallel and perpendicular type transitions are observed. The rotational structure has been fitted by least squares, and rotational and centrifugal distortion constants have been obtained for both states. The excited state exhibits many small perturbations. All lines observed are believed to originate from the trans form of hydroxylamine and no evidence for the cis isomer was found. Transitions belonging to a hot band, in which the low-energy torsional motion is excited in both the ground and upper states, have been located and assigned.