Unconventional single-molecule conductance behavior for a new heterocyclic anchoring group: Pyrazolyl
| Autor: | Iain Grace, I. Lucía Herrer, Richard J. Nichols, Andrea Vezzoli, José Luis Serrano, Ali K. Ismael, Alejandro González-Orive, David C. Milan, Colin J. Lambert, Santiago Martín, Pilar Cea |
|---|---|
| Přispěvatelé: | Engineering and Physical Sciences Research Council (UK), Ministerio de Economía y Competitividad (España), European Commission, Ministry of Higher Education and Scientific Research (Iraq), Diputación General de Aragón, University of Tikrit |
| Rok vydání: | 2018 |
| Předmět: |
Materials science
Conductance Anchoring Protonation 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Crystallography Electrical resistance and conductance Group (periodic table) Electrode Molecule Moiety General Materials Science Physical and Theoretical Chemistry 0210 nano-technology |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname The Journal of Physical Chemistry Letters |
| Popis: | Electrical conductance across a molecular junction is strongly determined by the anchoring group of the molecule. Here we highlight the unusual behavior of 1,4-bis(1H-pyrazol-4-ylethynyl)benzene that exhibits unconventional junction current versus junction-stretching distance curves, which are peak-shaped and feature two conducting states of 2.3 × 10-4 G0 and 3.4 × 10-4 G0. A combination of theory and experiments is used to understand the conductance of single-molecule junctions featuring this new anchoring group, i.e., pyrazolyl. These results demonstrate that the pyrazolyl moiety changes its protonation state and contact binding during junction evolution and that it also binds in either end-on or facial geometries with gold contacts. The pyrazolyl moiety holds general interest as a contacting group, because this linkage leads to a strong double anchoring of the molecule to the gold electrode, resulting in enhanced conductance values. P.C. and J.L.S. are grateful for financial assistance from Ministerio de Economía y Competitividad from Spain and fondos FEDER in the framework of projects MAT2016-78257-R and CTQ2015-70174-P, respectively. J.L.S. also acknowledges the funded project Hierarchical Self Assembly of Polymeric Soft Systems, “SASSYPOL”, from the seventh Framework Programme (CEE, ref-607602). L.I.H., S.M., J.L.S, and P.C. acknowledge support from DGA/Fondos FEDER (construyendo Europa desde Aragón) for funding PLATON (E31_17R) and CLIP (E47_17R) research groups. This work was additionally supported by the EPSRC “QuEEN” programme Grant EP/N017188/1. Further support from the UK EPSRC is acknowledged, through Grant Nos. EP/M014452/1, EP/P027156/1, and EP/N03337X/1. Support from the European Commission is provided by the FET Open project 767187 – QuIET and the Iraqi Ministry of Higher Education (SL-20). A.K.I. acknowledges financial support from Tikrit University (Iraq). D.C.M., A.V. and R.J.N. gratefully acknowledge funding by EPSRC through grants EP/M005046/1, EP/M014169/1, and EP/M029522/1. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|