Adsorption Behavior of 9-Anthracenecarboxylic Acid on (110) Rutile TiO2

The adsorption behavior of 9-anthracenecarboxylic acid (AnCA) on a rutile TiO2 (110) surface has been investigated with scanning tunneling microscopy (STM) at room temperature. Upon deposition, the molecules adsorb, resulting in a commensurate herringbone c-(2 x 2) structure, as confirmed by low-energy electron diffraction (LEED). Annealing of the sample below the desorption point causes irreversible superstructure derangement. Thermally programmed desorption (TPD) reveals that, after prior decomposition on the surface, AnCA molecules desorb into anthracenes and carboxyl acid derivatives.