FAR-INFRARED LASER MAGNETIC RESONANCE SPECTROSCOPIC STUDY OF THE $\nu_{2}$ BENDING FUNDAMENTAL OF THE CCN RADICAL IN ITS $\tilde{X}T^{2}II$, STATE

$^{a}$ H. Kohguchi, Y. Ohshima, Y. Endo, J. Chem. Phys. 106, 5429 (1997). $^{b}$ Y. Ohshima and Y. Endo, J. Molec. Spectros. 172, 225-232 (1995). $^{c}$ Calculated from data reported in M. Kakimoto and T. Kasuya, J.Molec. Spectros. 94, 380-392 (1982) and K. Kawaguchi, T. Suzuki, S. Saito, and E. Hirota, J. Molec. Spectros. 106, 320-329 (1984).Author Institution: Time and Frequency Division, National Institute of Standards and Technology; The Physical Chemistry Laboratory, Oxford UniversityVibration-rotation transitions between the $(010) \mu^{2}\Sigma^{-}(000)\bar{X}^{2}II_{r}$ vibronic states, were recorded using far-infrared laser magnetic resonance (FIR-LMR) spectroscopic techniques. These transitions occur near $200 cm^{-1}$ for the $(010) \mu^{2}\Sigma^{-} - (000) \tilde{X}^{2}II_{1/2}$ transition and $160 cm^{-1}$ for the $(010) \mu^{2}\Sigma^{-}-(000)\bar{X}^{2}\Pi_{3/2}$ transition. This is the first direct measurement of the $\nu_{2}$ band of CCN and with the inclusion of optical data, similar to the one found in the paper by Kohguchi $et al.^{a}$, microwave data from Ohshima and $Endo^{b}$, and spin-orbit $data^{c}$ a least squares fit has resulted in an accurate determination of molecular parameters for the ground and the $(010) \mu^{2}\Sigma^{-}$ states. The data were fit using an $N^{2}$ effective Hamiltonian modified to include the Renner-Teller effect