SPECULAR REFLECTION SPECTRA OF TETRACYANO-p-QUINODIMETHANE SINGLE CRYSTALS

Abstract

The polarized specular reflection spectra of tetracyano-p-quinodimethane single crystals have been obtained for three different faces. The $^{1}{B}_{u}\leftarrow ^{1}{A}_{e}$ transition displays metallic reflection. This band possesses structure beyond that expected for metallic reflection and the structure is attributed to a vibrational progression. Spectra of the molecule in the vapor phase and in a glass are compared to the crystal spectra. Analysis of the metallic reflection is made by exciton calculations. The influence of excition-phonon interaction on metallic reflection is also considered.