Accession Number : AD0635579

Title :   INFRARED SPECTRA OF MOLECULAR CRYSTALS.

Descriptive Note : Final technical rept.

Corporate Author : UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES

Personal Author(s) : Dows, David A. ; Audermann,G. ; Rubenstein,L. ; Rich,N.

Report Date : 31 MAY 1966

Pagination or Media Count : 14

Abstract : Studies were carried out to characterize and explain the infrared absorption and reflectance spectra of molecular crystals. Accurate methods of measuring reflectance spectra and of processing the data to obtain optical constants were developed and applied to sodium chlorate. Absolute infrared absorption intensities were measured for ethylenes, benzenes, acetylene and ethane. Theoretical studies of crystal splitting and lattice frequencies in benzene have provided data concerning intermolecular forces in this crystal splitting of ungerade vibrations, and provide the restoring force for torsional lattice motion. Phase changes in adamantane, cyclohexane and hexamethylbenzene were studied. Spectroscopically observable changes occuring at the phase transition temperature yield information concerning the molecular motions. Crystal spectra were used to aid in vibrational assignment of hydrazoic acid and cyclohexane. The unique properties of the crystal spectrum were of critical value in each case. (Author)

Descriptors :   (*INFRARED SPECTROSCOPY, *CRYSTALS), REFLECTION, ABSORPTION SPECTRA, INTENSITY, MOLECULAR ASSOCIATION, CRYSTAL LATTICES, PHASE STUDIES, CRYSTAL STRUCTURE, MOLECULAR STRUCTURE, POLYCYCLIC COMPOUNDS

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

Distribution Statement : APPROVED FOR PUBLIC RELEASE