Jet-Cooled Multiphoton Ionization Spectroscopy of the iso-Butanal 3s<--n Rydberg Transition.
We report the results of a study on the vibrational structure in the (n, 3s) Rydberg state of iso-butanal, carried out via 2+1 multiphoton ionization spectroscopy in a supersonic expansion. Spectra were recorded for both the normal species, (CH(3))(2)CHCHO, and the deuterated isotopomer, (CH(3))(2)CDCHO. The spectra show a complicated vibrational pattern attributable to the gauche (C(1)) conformer which is known to be 250 cm(-1) lower in energy than the more symmetric trans (C(s)) conformer. The spectra are dominated by the low-frequency formyl torsion which appears in combination with the two methyl torsions (in-phase and out-of-phase) and with several skeletal modes. Vibrational assignments have been aided by ab initio calculations of the (n, 3s) Rydberg state. Copyright 2001 Academic Press.
Department of Chemistry, University of Adelaide, Adelaide, South Australia, 5005, Australia
G. F.
GF
Metha
M. A.
MA
Buntine
A. J.
AJ
Bradley
R. J. S.
RJ
Morrison