PERTURBATIONS IN THE 2-NU-9 AND NU-8 BANDS OF PROPYNE-D

The analysis of the complex rotational structures of the 2nu9 parallel band and the nu8 perpendicular band of CH3CCD is presented. All the l evels of 2nu9(A1) and nu8(E) states are perturbed to varying degrees. A large number of off-diagonal perturbations connecting a quartet of i nteracting states, which include the E component of 2nu9 and the (A1, A2) component of (2nu10 + nu9), account for the observed complex patte rn. A few transitions of the type DELTAK = +2 to the 2nu9(E) state and DELTAK = 0 to the (2nu10 + nu9)(A1, A2) state have also been identifi ed. The major interactions are Fermi resonance between 2nu9(A1) and th e lower component of (2nu10 + nu9)(A1, A2), Fermi resonance between 2n u9(E) and nu8(E), ''+/-2, +/-2'' l-type resonance between 2nu9(A1) and 2nu9(E), and xy-Coriolis interaction between 2nu9(A1) and nu8(E). Par ameters of the four states and the interaction parameters have been de termined. (C) 1994 Academic Press, Inc.