Kinetic Study on Monolayer Formation with 4-Aminobenzenethiol on a Gold Surface
| Autor: | Nobuyuki Mohri, Kenichi Yoshikawa, Morimasa Inoue, Yoshifumi Arai |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
chemistry.chemical_classification
Ethanol Stereochemistry Inorganic chemistry Surfaces and Interfaces Activation energy equipment and supplies Condensed Matter Physics Metal chemistry.chemical_compound Adsorption Reaction rate constant chemistry Desorption visual_art Monolayer Electrochemistry Thiol visual_art.visual_art_medium General Materials Science Spectroscopy |
| Zdroj: | Langmuir. 11:1612-1616 |
| ISSN: | 1520-5827 0743-7463 |
| DOI: | 10.1021/la00005a033 |
| Popis: | Although thiol derivatives are often used to obtain a stable monomolecular layer on a gold metal surface, a detailed mechanism of the chemosorption has not been clarified yet. We study the adsorption kinetics of 4-aminobenzenethiol (ABT) onto the surface of gold powder in ethanol solution. It is found that ABT is spontaneously oxidized to 4,4'-diaminodiphenyl disulfide (DDD) in the presence of gold powder in ethanol and all of the ABT become DDD within a few hours, whereas the oxidative reaction of ABT is extremely slow in the absence of the gold powder. From a kinetic study on the production rate of DDD, the following mechanism is suggested. In the initial step, ABT is adsorbed on the gold surface and then oxidized to the thiolate. As the next step, the disulfide, DDD, is formed from thiolate and successively dissolved into the bulk solution. We obtained the rate constants and the activation energy concerning the adsorption of ABT and desorption of DDD and also estimated the occupied area by a single thiolate to be 22±2 A 2 |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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