Triboluminescence Spectroscopy of Aromatic Compounds

Abstract

The triboluminescence spectra of crystals of a variety of molecules containing aromatic groups are reported and assigned. The spectra are compared to the corresponding photoluminescence spectra of the crystals. Five general categories of triboluminescence are identified: fluorescence of the aromatic crystals, phosphorescence of the aromatic crystals, phosphorescence from metal centers in complexes, luminescence from charge transfer complexes, and fluorescence from the second positive group of molecular nitrogen. In general, the triboluminescence spectra are similar to the crystal photoluminescence spectra taken at the same temperature. However, in some cases significant differences are found. The TL spectra frequently contain features which are absent in the photoluminescent spectra, such as new emission bands or large changes in the relative intensities of bands. Some crystals which are triboluminescent are not photoluminescent. Similarities and differences between the photoluminescence and triboluminescence spectra are discussed. © 1977, American Chemical Society. All rights reserved.