Microscopic mechanism of electron transfer through the hydrogen bonds between carboxylated alkanethiol molecules connected to gold electrodes

Handle URI:
http://hdl.handle.net/10754/598831
Title:
Microscopic mechanism of electron transfer through the hydrogen bonds between carboxylated alkanethiol molecules connected to gold electrodes
Authors:
Li, Yang; Tu, Xingchen; Wang, Minglang; Wang, Hao; Sanvito, Stefano; Hou, Shimin
Abstract:
© 2014 AIP Publishing LLC. The atomic structure and the electron transfer properties of hydrogen bonds formed between two carboxylated alkanethiol molecules connected to gold electrodes are investigated by employing the non-equilibrium Green's function formalism combined with density functional theory. Three types of molecular junctions are constructed, in which one carboxyl alkanethiol molecule contains two methylene, -CH2, groups and the other one is composed of one, two, or three -CH2 groups. Our calculations show that, similarly to the cases of isolated carboxylic acid dimers, in these molecular junctions the two carboxyl, -COOH, groups form two H-bonds resulting in a cyclic structure. When self-interaction corrections are explicitly considered, the calculated transmission coefficients of these three H-bonded molecular junctions at the Fermi level are in good agreement with the experimental values. The analysis of the projected density of states confirms that the covalent Au-S bonds localized at the molecule-electrode interfaces and the electronic coupling between -COOH and S dominate the low-bias junction conductance. Following the increase of the number of the -CH2 groups, the coupling between -COOH and S decreases deeply. As a result, the junction conductance decays rapidly as the length of the H-bonded molecules increases. These findings not only provide an explanation to the observed distance dependence of the electron transfer properties of H-bonds, but also help the design of molecular devices constructed through H-bonds.
Citation:
Li Y, Tu X, Wang M, Wang H, Sanvito S, et al. (2014) Microscopic mechanism of electron transfer through the hydrogen bonds between carboxylated alkanethiol molecules connected to gold electrodes. J Chem Phys 141: 174702. Available: http://dx.doi.org/10.1063/1.4900511.
Publisher:
AIP Publishing
Journal:
The Journal of Chemical Physics
KAUST Grant Number:
FIC/2010/08
Issue Date:
7-Nov-2014
DOI:
10.1063/1.4900511
PubMed ID:
25381533
Type:
Article
ISSN:
0021-9606; 1089-7690
Sponsors:
This project was supported by the National Natural Science Foundation of China (No. 61321001) and the MOST of China (Nos. 2011CB933001 and 2013CB933404). S.S. thanks additional funding support from the European Research Council (QUEST project), by KAUST (FIC/2010/08) and by AMBER (12/RC/2278).
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Publications Acknowledging KAUST Support

Full metadata record

DC FieldValue Language
dc.contributor.authorLi, Yangen
dc.contributor.authorTu, Xingchenen
dc.contributor.authorWang, Minglangen
dc.contributor.authorWang, Haoen
dc.contributor.authorSanvito, Stefanoen
dc.contributor.authorHou, Shiminen
dc.date.accessioned2016-02-25T13:42:04Zen
dc.date.available2016-02-25T13:42:04Zen
dc.date.issued2014-11-07en
dc.identifier.citationLi Y, Tu X, Wang M, Wang H, Sanvito S, et al. (2014) Microscopic mechanism of electron transfer through the hydrogen bonds between carboxylated alkanethiol molecules connected to gold electrodes. J Chem Phys 141: 174702. Available: http://dx.doi.org/10.1063/1.4900511.en
dc.identifier.issn0021-9606en
dc.identifier.issn1089-7690en
dc.identifier.pmid25381533en
dc.identifier.doi10.1063/1.4900511en
dc.identifier.urihttp://hdl.handle.net/10754/598831en
dc.description.abstract© 2014 AIP Publishing LLC. The atomic structure and the electron transfer properties of hydrogen bonds formed between two carboxylated alkanethiol molecules connected to gold electrodes are investigated by employing the non-equilibrium Green's function formalism combined with density functional theory. Three types of molecular junctions are constructed, in which one carboxyl alkanethiol molecule contains two methylene, -CH2, groups and the other one is composed of one, two, or three -CH2 groups. Our calculations show that, similarly to the cases of isolated carboxylic acid dimers, in these molecular junctions the two carboxyl, -COOH, groups form two H-bonds resulting in a cyclic structure. When self-interaction corrections are explicitly considered, the calculated transmission coefficients of these three H-bonded molecular junctions at the Fermi level are in good agreement with the experimental values. The analysis of the projected density of states confirms that the covalent Au-S bonds localized at the molecule-electrode interfaces and the electronic coupling between -COOH and S dominate the low-bias junction conductance. Following the increase of the number of the -CH2 groups, the coupling between -COOH and S decreases deeply. As a result, the junction conductance decays rapidly as the length of the H-bonded molecules increases. These findings not only provide an explanation to the observed distance dependence of the electron transfer properties of H-bonds, but also help the design of molecular devices constructed through H-bonds.en
dc.description.sponsorshipThis project was supported by the National Natural Science Foundation of China (No. 61321001) and the MOST of China (Nos. 2011CB933001 and 2013CB933404). S.S. thanks additional funding support from the European Research Council (QUEST project), by KAUST (FIC/2010/08) and by AMBER (12/RC/2278).en
dc.publisherAIP Publishingen
dc.titleMicroscopic mechanism of electron transfer through the hydrogen bonds between carboxylated alkanethiol molecules connected to gold electrodesen
dc.typeArticleen
dc.identifier.journalThe Journal of Chemical Physicsen
dc.contributor.institutionCentre for Nanoscale Science and Technology, Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, Chinaen
dc.contributor.institutionSchool of Physics, AMBER and CRANN Institute, Trinity College, Dublin 2, Irelanden
kaust.grant.numberFIC/2010/08en

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