THE HIGH-RESOLUTION INFRARED-SPECTRUM OF FNO2 BETWEEN 500 AND 900 CM(-1) - THE NU(5), NU(3), NU(6), NU(2) CORIOLIS INTERACTING TETRAD

The gas-phase IR spectra of the nu(5), nu(3), nu(6), and nu(2) bands o f FNO2 have been studied at resolutions ranging from 0.0023 to 0.0050 cm(-1). These bands form an isolated tetrad which is coupled by a-, b- , and c-Coriolis resonances. The c-Coriolis interaction between nu(3) and nu(5) is particularly strong. From a ground state combination diff erence analysis the following ground state rotational constants have b een obtained: A = 0.440348960(17) cm(-1), B = 0.381803994(17) cm(-1), and C = 0.204107899(13) cm(-1). A simultaneous upper state analysis wi th a four level model based on the Watson asymmetric top Hamiltonian a nd laking into account Coriolis interactions has been performed. A set of spectroscopic parameters for the nu(5), nu(3), nu(6), and nu(2) le vels has been obtained. (C) 1997 Academic Press.