10min:

A. CHIROKOLAVA, X. WANG, T. J. CRONIN AND D. S. PERRY, Department of Chemistry, University of Akron, Akron, OH 44325-3601; L.-H. XU, Department of Physical Sciences, University of New Brunswick, Saint John, New Brunswick, Canada E2L 4L5.

High-resolution infrared spectra of the ¹³C-methanol ₁ band have been obtained by slit-jet absorption spectroscopy. A total of 1278 lines have been recorded from 3665 to 3708~cm^-1 with several "holes" resulting from strong water absorption lines. Thirty five subbands of the ₁ band with K~=~0, 1, 2 have been assigned based on polynomial fits and ground-state combination differences. Half of the upper states are split by perturbations with matrix elements in the range of 1-3~cm^-1. The deperturbed data show an approximately regular pattern of torsional energies with a torsional tunnelling splitting of 7~cm^-1 at K~=~0.