Low variability of single-molecule conductance assisted by bulky metal-molecule contacts
| Autor: | Paul J. Low, Andrea Vezzoli, Pilar Cea, Santiago Martín, Richard J. Nichols, Jaime Ferrer, Henrry M. Osorio, David C. Milan, Víctor M. García-Suárez, Santiago Marqués-González, Simon J. Higgins, R. Ferradás |
|---|---|
| Přispěvatelé: | Ministerio de Educación (Ecuador), Secretaría de Educación Superior, Ciencia, Tecnología e Innovación (Ecuador), Australian Research Council, European Commission, Engineering and Physical Sciences Research Council (UK), Ministerio de Educación (España), Ministerio de Economía y Competitividad (España), Principado de Asturias, Diputación General de Aragón |
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Steric effects
Stereochemistry Chemistry General Chemical Engineering Conductance 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 3. Good health 0104 chemical sciences Crystallography Phenylene Molecule Moiety Molecular orbital Density functional theory 0210 nano-technology Break junction |
| Zdroj: | RSC ADVANCES Scopus Digital.CSIC. Repositorio Institucional del CSIC instname RUO. Repositorio Institucional de la Universidad de Oviedo |
| Popis: | A detailed study of the trimethylsilylethynyl moiety, –C[triple bond]CSiMe3 (TMSE) , as an anchoring group in metalmoleculemetal junctions, using a combination of experiment and density functional theory is presented. It is shown that the TMSE anchoring group provides improved control over the molecule-substrate arrangement within metalmoleculemetal junctions, with the steric bulk of the methyl groups limiting the number of highly transmissive binding sites at the electrode surface, resulting in a single sharp peak in the conductance histograms recorded by both the in situ break junction and I(s) STM techniques. As a consequence of the low accessibility of the TMSE group to surface binding configurations of measurable conductance, only about 10% of gold break junction formation cycles result in the clear formation of molecular junctions in the experimental histograms. The DFT-computed transmission characteristics of junctions formed from the TMSE-contacted oligo(phenylene)ethynylene (OPE)-based molecules described here are dominated by tunneling effects through the highest-occupied molecular orbitals (HOMOs). This gives rise to similar conductance characteristics in these TMSE-contacted systems as found in low conductance-type junctions based on comparably structured OPE-derivatives with amine-contacts that also conduct through HOMO-based channels. R. R. F. thanks the Consejería de Educación del Principado de Asturias for a Severo Ochoa grant (BP11-069). V. M. G.-S. thanks the Spanish Ministerio de Economía y Competitividad for a Ramón y Cajal fellowship (RYC-2010-06053). R. R. F., J. F. and V. M. G.-S. wish to acknowledge financial support from the Spanish grant FIS2012-34858 and the Marie Curie Network MOLESCO. P. C. and S. M. are grateful for financial assistance from the Ministerio de Economía y Competitividad of Spain in the framework of the project CTQ2012-33198 as well as the award of the CTQ2013-50187-EXP grant. H. M. O., P. C., and S. M. thank the support from DGA and Fondos FEDER for funding through the Platon research group. H. M. O. is also grateful for financial assistance from the Secretaría Nacional de Educación Superior, Ciencia, Tecnología e Innovaciín from Ministerio de Educación (Ecuador). S. M. thanks the Ministerio de Educación from Spain for financial support through the framework of the Campus de Excelencia Internacional, CEI Iberus. S. J. H., R. J. N., P. J. L. and S. M.-G. thank the EPSRC for funding (EPSRC grants EP/K007785/1, EP/H035184/1, EP/K007548/1, EP/H005595/1). P. J. L. holds an Australian Research Council Future Fellowship (FT120100073) and gratefully acknowledges funding for this work from the ARC (DP140100855). |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|