THE NU-6-BAND OF (CH3I)-C-13

The infrared spectrum of the perpendicular fundamental band ν6 of 13CH3I in the region 765-1035 cm-1 has been studied at a resolution of 0.0021 cm-1. More than 3800 transitions were assigned for subbands from KΔK = -15 to KΔK = +17, including J values up to 75. The ground state constants were derived using 2943 ground state combination differences from ν6 and 2ν3 bands together with 90 rotational transitions from the literature. In the analysis of the v6 = 1 state the Coriolis resonance with the v3 = 2 state was taken into account. The molecular constants concerning the fundamental ν6, as well as the parameters describing the Coriolis and l(2, 2) resonances, were derived. The assignments of optically pumped FIR laser lines are also discussed. © 1991.