High-Resolution Vibrational Spectra of Furazan II. The B1 Fundamental ν 11 at ~ 1175 cm–1 from Fourier-Transform Infrared Spectroscopy

The high-resolution FT-IR spectrum of the A-type fundamental ν11 of furazan ( C2H2N20) has been recorded and analysed against the background of rotational information from DRM microwave spectroscopy to yield the band origin as ν110= 1175.3377 + 0.0001 cm-1 . The combined use of microwave (MW) and FT-IR data gives this band origin with a statistical uncertainty of σ= 10-6cm-1 and leads to a refinement of the rotational constants of the state ν11 = 1 over those derivable from either MW or FT-IR data alone