Experimental observation of the ν1+3ν3 combination bands of 16O14N18O and 18O14N18O in the near infrared spectral region

Abstract

The first observation of the ν1+3ν3 combination band of the nitrogen dioxide isotopologue 16O14N18O is presented. The band was measured using Fourier-Transform Incoherent Broad-Band Cavity Enhanced Absorption Spectroscopy (FT-IBBCEAS) in the region between 5870 cm−1 and 5940 cm−1. To confirm the assignment, the band was simulated using a standard asymmetric top Watson Hamiltonian using extrapolated rotational and centrifugal distortion constants. Furthermore, the first experimental observation of the ν1+3ν3 band of the 18O14N18O isotopologue is also reported. The positions of ro-vibrational lines of the ν1+3ν3 band of the naturally most abundant isotopologue 16O14N16O were used for wavenumber calibration of line positions.

Keywords

• Cavity enhanced absorption spectroscopy
• Fourier transform (FT)
• FT-IBBCEAS
• Near infrared (IR)
• Nitrogen dioxide
• Isotopologues