ABSTRACT
Torsional splittings of the C2H6 hot band nu9 + nu4 - nu4 have been determined based on measurements taken with the Kitt Peak National Observatory Fourier transform spectrometer with .0025 cm-1 resolution. The measured splittings range from -.2347 cm-1 (the sign is relative to that of the observed splitting in the nu9 band of C2H6) to .0682 cm-1, with a standard deviation of the observed splittings of .0251 cm-1. The splittings can be explained as a result of xy Coriolis interaction of nu9 + nu4 with the excited torsional states taunu4, with the major effect arising from the "forbidden" interaction with the nearly degenerate state 5nu4final sigma = 2. The rms error of the predicted splittings is .00422 cm-1, if parameters determined from theory and previous work are used, and is .00217 cm-1, if small refinements to the parameters are made based on the measured splittings themselves. Copyright 1998 Academic Press.