Stark spectroscopy with the CO laser: The ν2 fundamental bands of trans- and cis-nitrous acid, HNO 2, in the 6-μm region

The ν₂ fundamental bands of trans- and cis-HNO ₂ have been studied by the technique of intracavity CO laser Stark spectroscopy. Excited-state rotational constants were determined, and the ν₂-band origins were found to be 1699.760 cm ^-1 for the trans isomer and 1640.517 cm ^-1 for the cis isomer. The total dipole moments for the ground and excited ( v₂ = 1) vibrational states were found to be μ″ = 1.930 D and μ″ = 1.852 D for trans-HNO ₂, and μ″ = 1.428 D and μ″ = 1.441 D for cis-HNO ₂.