Abstract
Rotationally resolved spectra of transitions involving methyl torsion and C-C-O bend of acetaldehyde in the system of à 1 A″-X̃ 1 A′ were studied. The torsion spacing obtained for series 10 1 14 0+ and 10 1 14 0- was slightly smaller than those for states in series 14 0+ and 14 0- . The results show that torsional spacings observed in the C-C-O bend series are slightly smaller than those in the pure torsional series.