Vibrational overtone spectroscopy of jet-cooled methanol from 5000 to 14 000 cm(-1).
Spectra of jet-cooled methanol in the overtone and combination region from 5000 to 14 000 cm(-1) have been obtained by means of infrared laser-assisted photofragment spectroscopy. Many of the observed features are assigned to combination bands of the type nnu(1)+nu(6), nnu(1)+nu(8), and nnu(1)+nu(6)+nu(8) (n=1,2,3), where nu(1) is the OH stretch, nu(6) is the OH bend, and nu(8) is the CO stretch. These bands show sharp torsion-rotation structure with features as narrow as 0.1 cm(-1). We also observe CH stretch overtones that are weaker than the OH containing combination bands and lack distinct torsion-rotation structure above v(CH)=2. The extent of observed structure on these bands allows us to place limits on the intramolecular vibrational energy redistribution decay rates in the upper vibrational states. We report a global fit of the observed band centers to a simple expression involving low-order anharmonicity constants.
Rueda
David
D
Laboratoire de Chimie Physique Moléculaire, EPFL, Station-6, CH-1015 Lausanne, Switzerland. rueda@umich.edu
Boyarkin
Oleg V
OV
Rizzo
Thomas R
TR
Chirokolava
Andrei
A
Perry
David S
DS