ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Infrared cavity ringdown laser absorption spectroscopy has been used to study the O–H stretching vibrations of jet-cooled methanol clusters in direct absorption. Rovibrational bands for (CH3OH)2, (CH3OH)3, and (CH3OH)4 have been measured. Both bonded and free O–H stretches were measured for the dimer, indicating that its structure is linear. Five bands were assigned to the methanol trimer, indicating the presence of a second cyclic isomer in the molecular beam. A detailed study of the free O–H stretching region shows that methanol clusters larger than dimer must exist in cyclic ring configurations. In order to facilitate spectral assignment, harmonic frequencies and infrared intensities were calculated for the methanol monomer, dimer, and trimer with second order Møller–Plesset perturbation theory. Using the theoretical infrared intensities and measured vibrational band absorptions, absolute cluster concentrations were calculated. Results agree with previous experimental and theoretical work. © 1999 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.478309
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