Six previously unobserved lines for the bent form of NNO-HF (O...H hydrogen bonded) were measured using a pulsed-beam, Fourier-transform spectrometer. These lines, together with earlier data, were fitted to obtain the rotational constants and a limited set of quartic distortion constants using a Watson-type Hamiltonian in the Ir representation. The results of the fit are: A+Δ K=26322.32(32) MHz, B=2720.93(10) MHz, C=2438.72 (10) MHz, ΔJ=60.3(11) kHz, ΔJK=-3.077(15) MHz, δJ= 13.1(10) kHz and δK= 314 (47) kHz. The errors in line frequencies calculated with this extended set of parameters are two orders of magnitude smaller than errors obtained using only rigid rotor parameters. The vibrationally averaged structure and force constants for the Rc.m. stretching vibration and an in-plane-bending vibration were calculated using the rotational constants and distortion constants. It was found that ΔJ (or DJ) depends primarily on fRR-1, so that earlier analyses involvi ΔJ or DJ were reasonably accurate.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry