Slit jet infrared absorption spectroscopy of N2-HCl complexes

Abstract

The vibration–rotation spectra of the weakly bound complexes N₂-HCl have been studied in the 3·5 μm region of the υ₁ fundamental band correlated with the HCl stretch, using a pulsed slit jet expansion and a tunable diode laser spectrometer. For the first time the υ₁ band for the N₂-H³⁷ Cl isotope has been analysed and the rotational constants determined. The υ₁ band was observed previously for the N²– H³⁵ Cl isotope using a cooled long path cell and a Fourier transform spectrometer. This band has been re-examined to confirm and extend this analysis, with new lines corresponding to low J values observed and assigned. The rotational molecular constants are in agreement with those determined already, but for the band centre the value found was slightly greater than those obtained previously. For both isotopes, the observed spectra confirm the quasilinear geometry of the complex.