HIGH-RESOLUTION TDL SPECTROSCOPY OF THE NU(6) BAND OF CH2=(CHCL)-CL-37

The gas-phase infrared spectrum of monoisotopic (CH3CHCl)-Cl-37 (isoto pic purity, 95%) has been recorded in the upsilon(6) band region betwe en 1263 and 1297 cm(-1), at Doppler-limited resolution, employing a tu nable diode laser spectrometer. This vibration of symmetry species A' yields an a/b hybrid band with a prevalent contribution of the a-type component. The rovibrational analysis in the P, Q, and R branches led to the assignment of about 1400 lines with J less than or equal to 48 and K-a less than or equal to 16. A number of K-a subbands were found to be affected by Coriolis-type resonance, and the upsilon(9) + upsilo n(11) level was identified as the perturber. From a simultaneous fit o f the present GSCD, together with literature microwave data, a set of ground state constants up to the sextic coefficients has been obtained using Watson's A-reduction Hamiltonian in the I' representation. A le ast-squares fit of about 1170 transitions, free of major resonance con tribution, provided a set of effective upper-state constants for the u psilon(6) band of CH2 = (CHCl)-Cl-37. (C) 1994 Academic Press, Inc.