The conductance and thermopower behavior of pendent trans-coordinated Palladium(II) complexes in cingle-molecule junctions

Bastante, Pablo ; Davidson, Ross J. ; Al Malki, Wafa ; Salthouse, Rebecca J. ; Cea, Pilar (Universidad de Zaragoza) ; Martin, Santiago (Universidad de Zaragoza) ; Batsanov, Andrei S. ; Lambert, Colin J. ; Bryce, Martin R. ; Agrait, Nicolas

Resumen: 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 properties within 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 to give the trans-Pd(Lm or p)Cl2 complexes. X-ray photoelectron spectroscopy (XPS) measurements shed light on the contacting modes of the molecules in the junctions. A combination of scanning tunneling 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. Simultaneously there was a modest increase in both conductance and Seebeck coefficient due to the contraction of the HOMO–LUMO gap upon metal coordination. It is shown that the low Seebeck coefficient is primarily a consequence of how the resonances shift relative to the Fermi energy

Idioma: Inglés

DOI: 10.1021/acsomega.4c06475

Año: 2024

Publicado en: ACS OMEGA 9, 36 (2024), 38303-38312
ISSN: 2470-1343

Financiación: info:eu-repo/grantAgreement/ES/DGA/E31-23R
Financiación: info:eu-repo/grantAgreement/EC/H2020/767187/EU/Quantum Interference Enhanced Thermoelectricity/QuIET
Financiación: info:eu-repo/grantAgreement/ES/MDM/CEX2018-000805-M
Financiación: info:eu-repo/grantAgreement/ES/MICINN/PID2020-114882GB-I00
Financiación: info:eu-repo/grantAgreement/ES/MICINN/PID2022-141433OB-I00
Financiación: info:eu-repo/grantAgreement/ES/MICINN/PRE2019-091388
Financiación: info:eu-repo/grantAgreement/EUR/MICINN/TED2021-131318B-I00

Tipo y forma: Artículo (Versión definitiva)

Área (Departamento): Área Química Física (Dpto. Química Física)