FAR-IR SPECTROSCOPY OF OZONE AS A MEANS OF QUANTIFICATION OF OZONE ISOTOPOMERS

The rotational spectrum of ozone in the far IR, obtained with a 0.004 cm(-1) resolution, has been used to quantify ozone isotopomers in an a rtificially produced mixture of normal and O-18 substituted ozone spec ies. Higher order terms in the dipole operator have been found to sign ificantly influence the theoretical line intensities of some of the ro tational transitions. A planarity relation between some of the theta-c onstants was found in this connection. The results have been used part ly to calibrate our microwave spectrometer for future ozone isotopomer quantification and partly to quantify the mixture studied. In particu lar the ratio r(50) between unsymmetric and symmetric species of mono- O-18 ozone has been determined with the aim of detecting possible devi ations from the statistical value 2.00; for the two mixtures studied r (50) = 2.12(9) and r(50) = 2.00(8). (C) 1996 Academic Press, Inc.