The CW-CRDS spectra of the 16O/18O isotopologues of ozone between 5930 and 6340 cm-1-Part 1: 16O16O18O

The first investigation of the very sensitive QV-Cavity Ring Down Spectra (noise equivalent absorption alpha(min) approximate to 1 x 10(-10) cm(-1)) of O-18 enriched ozone isotopologues is reported. The ozone generation from O-18 enriched oxygen molecules resulted in six isotopic species. The contributions of the (OOO)-O-16-O-16-O-18/(OOO)-O-16-O-18-O-16 and of the (OOO)-O-18-O-18-O-16/(OOO)-O-18-O-16-O-18 isotopomers were separated using two partial pressures of O-16(2)/O-18(2) mixtures. In the 5930-6340 cm(-1) range, the four dominant bands of (OOO)-O-16-O-16-O-18 were vibrationally assigned as 2v(1)+2v(2)+3v(3)_1, 2v(2)+5v(3), 5v(1)+v(3) and 2v(1)+2v(2)+3v(3)_2. They correspond to the highest vibration excitations observed so far in an asymmetric C-s ozone isotopologue. The rovibrational spectra for O-18 enriched C-s ozone species show specific features related to the nuclear spin statistics and to simultaneous symmetry allowed Coriolis and anharmonic accidental resonances, which are discussed. Altogether for the four new bands, 2155 rovibrational transitions were assigned up to J(max)=32. Observed line positions were fitted with rttis deviations ranging from 0.005 to 0.01 cm(-1) using effective Hamiltonian models accounting for dark state perturbations. The derived band centers and rotational constants are in good agreement with new theoretical calculations from the molecular potential function. The corresponding line lists are provided as Supplementary Material. (C) 2012 Elsevier Ltd. All rights reserved.