Microwave a-Dipole Transitions of CH2DOH and CHD2OH in Excited Torsional States

Previously identified, measured, and rotationally assigned but unpublished J = 0-1 and 1-2 microwave a-dipole lines for excited states of the torsion for CH2DOH and CHD2OH are given torsional assignments for the first four excited states. The troublesome assignments were for the K-1 = 0 lines of the o2 state of CH2DOH and the e2 state of CHD2OH, where a resonance is found for the J0J levels. The assignment for these states was facilitated by combination differences with the b- or c-dipole intratorsional state transitions, relative intensities, and FIR combination differences for the e2 and e3 states of CH2DOH. A few new b- and c-dipole assignments are reported for o2 of CH2DOH and e2 of CHD2OH. Transitions for these two states have been analyzed to estimate the strength of the resonant interaction and energy difference for the levels involved and to estimate how well the theory is predicting the K-1-dependent torsional energy levels. The empirically determined DeltaB and DeltaC from nonrigidity for each species for the four excited states should prove helpful for future calculations of vibration-internal rotation-overall rotation interactions in these molecules. Copyright 1998 Academic Press.