Accession Number : ADA182461

Title :   On the van der Waals Modes of Solute/Solvent Clusters: Benzene-Methane, -Deuteromethane, and -Carbon Tetrafluoride.

Descriptive Note : Technical rept.,

Corporate Author : COLORADO STATE UNIV FORT COLLINS DEPT OF CHEMISTRY

Personal Author(s) : Menapace,J A ; Bernstein,E R

PDF Url : ADA182461

Report Date : May 1987

Pagination or Media Count : 30

Abstract : Clusters of benzene (CD4)1 and (CF4)1 are created in a supersonic molecular jet and are studied by two-color time-of-flight mass spectroscopy. The clusters' S1 - So 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 (CH4)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 that motion is constrained by an orientationally dependent intermolecular potential whose barrier height is of the order of the cluster binding energy.

Descriptors :   *SOLUTES, *SOLVENTS, *CLUSTERING, *MOLECULE MOLECULE INTERACTIONS, BARRIERS, HEIGHT, NUCLEAR BINDING ENERGY, MOTION, COORDINATES, BENZENE, CARBON TETRAFLUORIDE, SPECTRA, EQUILIBRIUM(GENERAL), CHEMICAL BONDS, COMPLEX COMPOUNDS, MOLECULAR VIBRATION, MATHEMATICAL ANALYSIS, MOLECULAR ENERGY LEVELS, INTERNAL, TORSION, ROTATION, RIGIDITY, MASS SPECTROSCOPY, COLORS

Subject Categories : Atomic and Molecular Physics and Spectroscopy
      Organic Chemistry
      Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE