High resolution FTIR study of the v5 and v6 bands of CH2D35Cl:: analysis of resonances and determination of ground and upper state constants

The isotopically pure form of methyl chloride, (CH2DCl)-Cl-35, was synthesized and investigated by Fourier transform infrared spectroscopy with an unapodized resolution of 0.004 cm(-1) in the range 650-900 cm(-1), the region of the lowest fundamentals v(5) (827 cm(-1)) and v(6) (714 cm (-1)). These distinct bands have been analysed in detail in the P-, Q- and R- branches. In spite of their expected a/b-hybrid nature, both envelopes show the peculiar characteristic of only a-type bands of near prolate asymmetric top molecules. Ground state parameters have been determined for the first time through ground state combination differences from both bands. Parameters of the excited vibrational states and coupling constants have been obtained using a model which accounts for c-type Coriolis interaction and Delta Ka = +/- 2 anharmonic resonance.