Dimerization of three xanthene dyes on Au(1 1 1) surface
Abstract
The adsorption structures of three xanthene dyes (rhodamine B (Rh B), fluorescein and eosin) on Au(1 1 1) in HClO 4 solution, have been investigated by in situ scanning tunneling microscopy (STM) and cyclic voltammetry. High-resolution STM images reveal the molecular orientation and packing arrangement in the ordered adlayers. A (5 × 10) structure is found on Rh B adlayer. (5 × 8) structures are observed on fluorescein and eosin adlayers, respectively. An intriguing aspect of this work is that three xanthene molecules form dimeric structures on Au(1 1 1) surface. The electrostatic interaction and van der Waals force are responsible to the dimeric formation of Rh B, while the interaction between Br atoms and hydrogen bond correspond to the dimerization of eosin and fluorescein, respectively. The structural models are tentatively proposed for the three ordered adlayers. The results obtained will be helpful to understand the interaction mechanism of dimerization and the degradation mechanism of dye pollutant.
- Publication:
-
Surface Science
- Pub Date:
- March 2004
- DOI:
- 10.1016/j.susc.2003.12.046
- Bibcode:
- 2004SurSc.551..204S