Tuning Single-Molecule Conductance by Controlled Electric Field-Induced trans-to-cis Isomerisation
| Autor: | Denis Andrienko, Albert C. Aragonès, Ismael Díez-Pérez, Katrin F. Domke, Daniel Aravena, C.S. Quintans, Sangho Koo |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Electric fields molecular electronics Carotenoides Chemie 02 engineering and technology Electronic structure in-situ isomerisation 010402 general chemistry 01 natural sciences lcsh:Technology lcsh:Chemistry Isomerism Electric field Molecule General Materials Science single-molecule junctions Isomeria Instrumentation Camps elèctrics lcsh:QH301-705.5 Fluid Flow and Transfer Processes STM break-junction lcsh:T Process Chemistry and Technology General Engineering carotenoids Conductance 021001 nanoscience & nanotechnology Carotenoids lcsh:QC1-999 0104 chemical sciences Computer Science Applications lcsh:Biology (General) lcsh:QD1-999 Chemical physics lcsh:TA1-2040 Excited state 0210 nano-technology Break junction lcsh:Engineering (General). Civil engineering (General) Isomerization Cis–trans isomerism lcsh:Physics |
| Zdroj: | Applied Sciences, Vol 11, Iss 3317, p 3317 (2021) Applied Sciences Volume 11 Issue 8 |
| ISSN: | 2076-3417 |
| Popis: | External electric fields (EEFs) have proven to be very efficient in catalysing chemical reactions, even those inaccessible via wet-chemical synthesis. At the single-molecule level, oriented EEFs have been successfully used to promote in situ single-molecule reactions in the absence of chemical catalysts. Here, we elucidate the effect of an EEFs on the structure and conductance of a molecular junction. Employing scanning tunnelling microscopy break junction (STM-BJ) experiments, we form and electrically characterize single-molecule junctions of two tetramethyl carotene isomers. Two discrete conductance signatures show up more prominently at low and high applied voltages which are univocally ascribed to the trans and cis isomers of the carotenoid, respectively. The difference in conductance between both cis-/trans- isomers is in concordance with previous predictions considering π-quantum interference due to the presence of a single gauche defect in the trans isomer. Electronic structure calculations suggest that the electric field polarizes the molecule and mixes the excited states. The mixed states have a (spectroscopically) allowed transition and, therefore, can both promote the cis-isomerization of the molecule and participate in electron transport. Our work opens new routes for the in situ control of isomerisation reactions in single-molecule contacts. |
| Databáze: | OpenAIRE |
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