Raman Study of Crystalline Ethylenes and the Structure Determination through Model Calculations of the Lattice Spectra.

Abstract

Complete Raman spectra of the intra- and intermolecular regions of pure ethylene, ethylene-d4, and their dilute mixed crystals have been obtained. The observations agree with group theoretical predictions based on a C sub 2h, sup 5 space group. Model calculations of the Raman lattice spectra for the two possible molecular orientations consistent with this space group were undertaken to evaluate which of these two structures more satisfactorily reproduces the experimental results. Various sets of carbon-carbon, carbon-hydrogen, and hydrogen-hydrogen interaction parameters were used in the calculation of crystal energies, librational frequencies and relative Raman scattering intensities. The investigation provides strong evidence that the crystalline ethylene structure with P12(1)/n1 (C sub 2h, sup 5) space symmetry, the so-called 'b-structure', is correct. (Author)

Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1972
Accession Number
AD0749821

Entities

People

  • G. R. Elliott
  • George E. Leroi

Organizations

  • Michigan State University

Tags

DTIC Thesaurus Topics

  • Alkenes
  • Carbon Carbon Composites
  • Diffraction
  • Ethylenes
  • Frequency
  • Hydrogen
  • Intensity
  • Observation
  • Orientation (Direction)
  • Raman Scattering
  • Raman Spectra
  • Scattering
  • Spectra
  • Symmetry
  • Wave Phenomena

Fields of Study

  • Chemistry

Readers

  • Materials Science and Engineering.
  • Organic Chemistry
  • Software Engineering

Technology Areas

  • Space