Publication
Names
  • I. Freund
  • R. S. Halford
Title
Motions of Molecules in Condensed Systems. XIII. Polarized Infrared Spectrum of Single Crystals of Diacetylene
Abstract
The polarized infrared spectra of single crystals of diacetylene, as well as those of the liquid and the vapor, are presented and analyzed. Modes forbidden activity in the vapor are observed in the spectra of the condensed phases, as are combinations of molecular fundamentals with lattice modes. The crystal and liquid spectra exhibit frequency shifts and band broadenings that are characteristic of hydrogen bonding. The crystal system is found to be either orthorhombic or monoclinic with two or more molecules in the primitive unit cell. The molecules are essentially coplanar and this plane is the only symmetry element that may be present at the site. An orthorhombic structure, of Space Group P22$_1$2$_1$ with four molecules on sites of no symmetry, is proposed for the crystal.
Keywords
spectroscopy, transmission spectra, band position, band vibration mode, mid-IR, crystal, structure, liquid, molecular solid, C4H2
Content
spectral data, band list data, experimental physics
Year
1965
Journal
Journal of Chemical Physics
Volume
42
Number
12
Pages
4131 - 4137
Pages number
7
Document type
article
Publication state
published