van der Waals modes of solute/solvent clusters: benzene-methane, -deuteriomethane, and -carbon tetrafluoride

Journal Article · Thu May 21 04:00:00 EDT 1987 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100295a038· OSTI ID:6368000

Menapace, J A; Bernstein, E R

Clusters of benzene(CD/sub 4/)/sub 1/ and -(CF/sub 4/)/sub 1/ are created in a supersonic molecular jet and are studied by two-color time-of-flight mass spectroscopy. The clusters' S/sub 1/ reverse arrow S/sub 0/ intermolecular vibronic structures are characterized by calculational modeling of the clusters' intermolecular motion. The calculations include (1) an intermolecular normal-coordinate analysis (NCA) which treats all six van der Waals modes under a harmonic oscillator assumption and (2) a three-dimensional hindered rigid-rotor analysis (3D-HRRA) which treats the intermolecular torsional motion. Agreement between calculation and experiment is excellent for binding energy, symmetries, and van der Waals mode energies. The cluster spectra and calculated intermolecular modes are compared to those of benzene(CH/sub 4/)/sub 1/ reported previously. A major conclusion of this work is that the clusters behave rigidly with regard to internal rotation of the cluster subunits and that the clusters possess unique equilibrium geometries. The internal torsional motion is oscillatory and is constrained by an orientationally dependent intermolecular potential whose barrier height is of the order of the cluster binding energy.

• Research Organization: Colorado State Univ., Fort Collins
• OSTI ID: 6368000
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 91:11; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKANES
AROMATICS
BENZENE
BINDING ENERGY
CARBON TETRAFLUORIDE
DATA
DEUTERIUM COMPOUNDS
DYE LASERS
ENERGY
ENERGY LEVELS
EXCITED STATES
EXPERIMENTAL DATA
FLUID FLOW
FLUORINATED ALIPHATIC HYDROCARBONS
HALOGENATED ALIPHATIC HYDROCARBONS
HYDROCARBONS
HYDROGEN COMPOUNDS
INFORMATION
INTERMOLECULAR FORCES
JETS
LASERS
LIQUID LASERS
MASS SPECTROSCOPY
MEASURING INSTRUMENTS
METHANE
MOLECULAR STRUCTURE
NEODYMIUM LASERS
NORMAL-MODE ANALYSIS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
SOLID STATE LASERS
SOLUTES
SOLVENTS
SPECTROMETERS
SPECTROSCOPY
SUPERSONIC FLOW
TIME-OF-FLIGHT SPECTROMETERS
VAN DER WAALS FORCES
VIBRATIONAL STATES