Abstract

The optical features of organic molecules adsorbed to the surface of oxides, such as silica and alumina, can be strongly perturbed by the chemical properties of the surface adsorption sites. The topography of the surface as it relates to the fractal dimension and its relation to the nature and distribution of surface sites is important information if we are to be able to understand the photophysics and photochemistry of surface bound molecules. The work we report here is for the molecule 1,4 dihydroxyanthraquinone (DAQ, Quinizarin). This molecule provides striking evidence of how the surface of silica gel modifies the optical features of DAQ in different ways depending on the nature of the surface adsorption site.

© 1985 Optical Society of America