Abstract
The adsorption of a cationic metal complex, [Ru (phen) 3] 2+ (phen=1, 10-phenanthroline), onto a mica surface from its aqueous solution was investigated. An attention was focused on the effect of molecular chirality on adsorption behavior. The saturated adsorption was determined to be (1.7±0.1)×10-6 and (1.3±0.1)×10-6 mol g-1 for the racemic mixture and the Δ-or Δ-enantiomer, respectively. When adsorption was made from a partially resolved solution of [Ru (phen) 3](ClO4) 2, the increase of enantiomeric excess was observed in a supernatant with the progress of adsorption. The results indicated that [Ru (phen) 3] 2+ was adsorbed as a racemic pair rather than as an enantiomeric pair. Atomic force microscope observation showed that the surface remained smooth when a mica surface was in contact with an aqueous solution of racemic [Ru (phen) 3](ClO4) 2, while it changed from a smooth surface to rough one for the Δ-enantiomeric solution. The change was interpreted in terms of the formation of the compact bimolecular layer for the racemic mixture, while a rough multilayer adsorption layer was formed for the enantiomer.
