Accession Number : AD0474545

Title :   FAR INFRARED SPECTRA OF CRYSTALLINE ACETYLENES, C2H2 AND C2D2.

Descriptive Note : Technical rept.,

Corporate Author : PRINCETON UNIV NJ FRICK CHEMICAL LAB

Personal Author(s) : Anderson, A. ; Smith, William Hayden

Report Date : NOV 1965

Pagination or Media Count : 14

Abstract : The far infrared spectra of polycrystalline films of acetylene and fully deuterated acetylene were recorded at 77 k, using a commercial Michelson Interferometer. Two sharp bands are observed for each crystal, and the frequency change on deuteration leads to their assignment as translational lattice modes. From these and other spectroscopic results, deductions concerning the crystal structure, which has not been directly measured at this temperature, are made, and it is concluded that the most likely factor group is of D2h symmetry with two molecules per unit cell on C2h sites, a structure similar to those of crystalline carbon disulfide and the halogens. It is shown that the two-fold axis at the site does not coincide with the molecular axis, as previously implied. (Author)

Descriptors :   (*ALKYNES, INFRARED SPECTRA), CRYSTALS, DEUTERIUM COMPOUNDS, CRYSTAL STRUCTURE, TEMPERATURE, MEASUREMENT.

Subject Categories : Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE