Resolved torsional splitting in the n18 and n19- bands of propene

FT-jet spectra of propene were recorded at 0.005 cmK1 instrumental resolution around 950 cm-1. Thanks to the jet conditions, probably corresponding to Trot close to 80 K, the torsion degrees of freedom are efficiently cooled down and the fine structure of the n18 and n19 vibrational bands could be investigated. The bands are perturbed and approximate variation of the principal rotational constants are obtained, as well as band origins. The A/E torsional splitting appears totally unpredictable over the range of vibrational-torsional energy investigated. q 2005 Elsevier B.V. All rights reserved.