The Torsion–Inversion Energy Levels in theS1(n, π*) Electronic State of Acetaldehyde from High-Resolution Jet-Cooled Fluorescence Excitation Spectroscopy

✍ Scribed by H. Liu; E.C. Lim; C. Muñoz-Caro; A. Niño; R.H. Judge; D.C. Moule

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 601 KB
• Volume: 175
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.1996.0020

✦ Synopsis

The laser-induced fluorescence excitation spectrum (LIF) of acetaldehyde that results from the emission from the S 1 (n, p*) electronic state has been observed under very high resolution with a CW pulse-amplified laser under jet-cooled conditions. The origins of seven bands were determined by rotational analyses with a rigid-rotor Hamiltonian. The origins were fitted to a set of levels that were obtained from a Hamiltonian that employed flexible torsion-wagging large amplitude coordinates. The potential surface derived from the fitting procedure yielded barriers to torsion and inversion of 721.43 and 585.13 cm 01 , respectively. Minima in the potential hypersurface at u Å 58.6Њ and a Å 35.7Њ defined the corresponding equilibrium positions for the torsion and wagging coordinates.