Far infrared vibration-rotation-tunneling spectroscopy and internal dynamics of methane—water: A prototypical hydrophobic system

Abstract

Thirteen vibration-rotation-tunneling (VRT) bands of the CH4—H2O complex have been measured in the range from 18 to 35.5 cm-1 using tunable far infrared laser spectroscopy. The ground state has an average center of mass separation of 3.70 A-ring and a stretching force constant of 1.52 N/m, indicating that this complex is more strongly bound than Ar—H2O. The eigenvalue spectrum has been calculated with a variational procedure using a spherical expansion of a site—site ab initio intermolecular potential energy surface [J. Chem. Phys. 93, 7808 (1991)]. The computed eigenvalues exhibit a similar pattern to the observed spectra but are not in quantitative agreement. These observations suggest that both monomers undergo nearly free internal rotation within the complex.

Publisher

AIP Publishing

Publication Date

1-15-1994

Publication Title

Journal of Chemical Physics

Department

Chemistry and Biochemistry

Document Type

Article

DOI

https://dx.doi.org/10.1063/1.466569

Keywords

Far infrared radiation, Laser spectroscopy

Language

English

Format

text

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