The Conductance and Thermopower Behavior of Pendent Trans-Coordinated Palladium(II) Complexes in Single-Molecule Junctions
The present work provides insight into the effect of connectivity within isomeric 1,2-bis(2-pyridylethynyl)benzene (bpb) palladium complexes on their electron transmission propertieswithin gold|single-molecule|gold junctions. The ligands 2,2′-((4,5-bis(hexyloxy)-1,2-phenylene)bis-(ethyne-2,1-diyl))b...
| Autores: | , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Universidad Autónoma de Madrid |
| Repositorio: | Biblos-e Archivo. Repositorio Institucional de la UAM |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.uam.es:10486/715626 |
| Acceso en línea: | http://hdl.handle.net/10486/715626 https://dx.doi.org/10.1021/acsomega.4c06475 |
| Access Level: | acceso abierto |
| Palabra clave: | Física |
| Sumario: | The present work provides insight into the effect of connectivity within isomeric 1,2-bis(2-pyridylethynyl)benzene (bpb) palladium complexes on their electron transmission propertieswithin gold|single-molecule|gold junctions. The ligands 2,2′-((4,5-bis(hexyloxy)-1,2-phenylene)bis-(ethyne-2,1-diyl))bis(4-(methylthio)pyridine) (Lm) and 6,6′-((4,5-bis(hexyloxy)-1,2-phenylene)bis-(ethyne-2,1-diyl))bis(3-(methylthio)pyridine) (Lp) were synthesized and coordinated with PdCl2 togive the trans-Pd(Lm or p)Cl2 complexes. X-ray photoelectron spectroscopy (XPS) measurementsshed light on the contacting modes of the molecules in the junctions. A combination of scanningtunneling microscopy−break junction (STM−BJ) measurements and density functional theory(DFT) calculations demonstrate that the typical lower conductance of meta- compared with para-connected isomers in a molecular junction was suppressed upon metal coordination. Simultaneouslythere was a modest increase in both conductance and Seebeck coefficient due to the contraction ofthe HOMO−LUMO gap upon metal coordination. It is shown that the low Seebeck coefficient isprimarily a consequence of how the resonances shift relative to the Fermi energy |
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