Infrared crystal spectra of heterocyclic compounds. II. IR spectrum of selenophene in the solid state

Infrared spectra of solid selenophene at different temperatures, have been measured using polarized radiation. Just below the freezing point the selenophene molecule has a noticeable degree of ring-rigidity, allowing for a definite location in sites of lower symmetry than the molecular one. Dichroic behaviour of IR lines in the solid state enables us to attribute the bands to the relative symmetry species and give a tentative hypothesis for the space group of the crystalline selenophene.