Forming chemisorbed single-molecule junctions through loss of stable carbocations
Recent studies have found that "chemically inert" gold surfaces may drive S-C(sp3) bond cleavage reactions in thioether (-SR) linker groups, providing access to single-molecule junctions with chemisorbed Au-S contacts following the elimination of R+. Here, we demonstrate that such transfor...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/400131 |
| Acceso en línea: | http://hdl.handle.net/10261/400131 |
| Access Level: | acceso abierto |
| Palabra clave: | Molecular electronics Single-molecule conductance Scanning tunneling microscope-based break junction method DFT-NEGF Interfacial reactions Carbocation chemistry |
| Sumario: | Recent studies have found that "chemically inert" gold surfaces may drive S-C(sp3) bond cleavage reactions in thioether (-SR) linker groups, providing access to single-molecule junctions with chemisorbed Au-S contacts following the elimination of R+. Here, we demonstrate that such transformations occur more readily at elevated temperatures, rough surfaces, and in nonpolar solvents. We further show that a greater proportion of chemisorbed bonds are formed when R = -CPh3 or -C7H7 than when R = -tBu, consistent with the relative stability of [tBu]+ < [CPh3]+ ∼ [C7H7]+ carbocations. Our contact chemistry assignments are supported by first-principles transmission calculations, and we apply potential energy calculations to expose the relatively small influence of applied external electric fields on this bond breaking process. Together, this work provides a deeper understanding of reactivity at metal surfaces, of broad relevance to heterogeneous catalysis and critical to the stability and function of molecular junctions and monolayers. |
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