Diffusion and Reorientations in Crystalline Acetylene.

Abstract

Crystalline acetylene in its two solid modifications was studied by means of temperature dependent static and rotating frame spin-lattice relaxation time measurements between 188-122K. The pressure of molecular motions was established in both phases. Two types of motions were observedin the high temperature cubic phase. Calculations of the longitudinal relaxation time behavior, as well as second moment considerations, for models of twofold flipping of the acetylene molecule, are both in agreement with the spherical reorientation model. In the low temperature phase relatively slow twofold flips or, less likely, spherical reorientation occurs. Motional parameters such as activation energies, pre-exponential factors, etc., were deduced.

Document Details

Document Type
Technical Report
Publication Date
Jun 21, 1972
Accession Number
AD0747255

Entities

People

  • John A. Ripmeester
  • Shmuel Albert

Organizations

  • University of Illinois Urbana–Champaign

Tags

DTIC Thesaurus Topics

  • Acetylenes
  • Agreements
  • Alkynes
  • Diffusion
  • Energy
  • Heat Of Activation
  • High Temperature
  • Low Temperature
  • Measurement
  • Molecules
  • Relaxation Time

Readers

  • Organic Chemistry
  • Quantum spin resonance or Electron Paramagnetic Resonance spectroscopy.
  • Systems Analysis and Design