6-Mercaptopurine Self-Assembled Monolayers on Gold (001)-Hex: Revealing the Fate of Gold Adatoms
Thiol molecules adsorbed on gold became a model system for molecular self-assembly on metal substrates long ago. In most cases the strong molecule-gold interaction is able to restructure the substrate, resulting in vacancy islands and steps. Today it is widely accepted that gold adatoms produced by...
| Autores: | , , , , , , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2017 |
| País: | Argentina |
| Recursos: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositorio: | CONICET Digital (CONICET) |
| Idioma: | inglés |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/63302 |
| Acesso em linha: | http://hdl.handle.net/11336/63302 |
| Access Level: | acceso abierto |
| Palavra-chave: | self assembled monolayers 6 mercaptopurine Au 100 5x20 STM_LEED https://purl.org/becyt/ford/1.4 https://purl.org/becyt/ford/1 |
| Resumo: | Thiol molecules adsorbed on gold became a model system for molecular self-assembly on metal substrates long ago. In most cases the strong molecule-gold interaction is able to restructure the substrate, resulting in vacancy islands and steps. Today it is widely accepted that gold adatoms produced by this process form stable thiol-adatom complexes, usually termed "staples" (RS-Auad-SR or RS-Auad-SR-Auad-SR), which are the basic units of the self-assembled monolayers. Here we report on a different scenario for 6-mercaptopurine (6MP), a heterocyclic aromatic thiol, namely its adsorption on the Au(001)-(5 × 20) reconstructed surface. Our results show that 6MP lifts the reconstruction upon adsorption, thus ejecting a large excess of gold adatoms. Surprisingly, 6MP molecules prefer to arrange in highly ordered adatom-free domains in the bridging configuration, while the ejected adatoms form gold islands. Our investigation reveals that the formation of thiol-gold adatom complexes is not always a thermodynamically favored process but rather depends on the nature of the thiol molecule. |
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