High resolution electronic study of 16O 14N 16O, 16O 14N 18O and 18O 14N 18O: A rovibronic survey covering 11 800–14 380 cm −1

Abstract

The 11 800–14 380 cm −1 frequency range has been scanned for rotationally resolved rovibronic transitions in the A 2 B 2– X 2 A 1 electronic band system of the symmetric ( C 2 v ) 16O 14N 16O and 18O 14N 18O isotopologues and in the corresponding electronic band system of the asymmetric ( C s ) 18O 14N 16O isotopologue. The rotational analysis—reflecting minor differences in mass—in combination with symmetry induced spectral differences allows an identification of 68 16O 14N 16O vibronic levels, 26 18O 14N 18O vibronic levels and 51 18O 14N 16O vibronic levels. The bands are recorded using near infrared fluorescence spectroscopy and a piezo valve based pulsed molecular beam expansion of premixed 18O 2 and 14N 16O in Ar. The majority of the observed bands is rotationally assigned and can be identified as transitions starting from the vibrational ground state of one of the isotopologues. Numerous hot bands have also been identified. A comparison of the overall spectroscopic features of C 2 v vs. C s symmetric species provides qualitative information on symmetry dependence of vibronic couplings.