Kr Laser Research Articles

Raman scattering from molecular crystals—II. Anthracene

Abstract The Raman spectrum of single crystal and powdered anthracene has been measured at room temperature using He-Ne laser 6328 A and Kr laser 6471 A excitation and a double monochromator with digital detection and recording. A total of 105 lines were observed in the regions 200–1700 and 2900–3100 cm −1 . In addition, all Raman active lattice vibrations were observed. Clear correlations with intensities and line shapes of corresponding vibrations in naphthalene are discovered. A complete assignment to free-molecule fundamentals except for the C-H stretching region is proposed. The assignments are based on the correlations with naphthalene, on theoretical calculations and on polarization measurements.

Raman Effect in Cuprous Oxide Compared with Infrared Absorption

A complex Raman spectrum of Cu2O has been measured using the Kr laser line at 6471 Å, and comparison with the infrared absorption spectrum is made. An F2g Raman active phonon, postulated from symmetry considerations and infrared absorption measurements to lie at either 606 or 181 cm−1, could not be observed. Strong lines are, however, observed at 220, 204, and 192 cm−1.