Odd–Even Effect in Molecular Electronic Transport via an Aromatic Ring
| العنوان: | Odd–Even Effect in Molecular Electronic Transport via an Aromatic Ring |
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| المؤلفون: | Hadas Alon, Ayelet Vilan, Tatyana Bendikov, Haim Sazan, Tal Toledano, Sabyasachi Mukhopadhyay, Keti Lerman, Chaim N. Sukenik, David Cahen, Dan Thomas Major |
| المصدر: | Langmuir. 30:13596-13605 |
| بيانات النشر: | American Chemical Society (ACS), 2014. |
| سنة النشر: | 2014 |
| مصطلحات موضوعية: | chemistry.chemical_classification, Surfaces and Interfaces, Condensed Matter Physics, Contact angle, Crystallography, Molecular dynamics, chemistry.chemical_compound, Monomer, X-ray photoelectron spectroscopy, chemistry, Ellipsometry, Monolayer, Electrochemistry, Molecule, General Materials Science, Spectroscopy, Alkyl |
| الوصف: | A distinct odd-even effect on the electrical properties, induced by monolayers of alkyl-phenyl molecules directly bound to Si(111), is reported. Monomers of H2C═CH-(CH2)n-phenyl, with n = 2-5, were adsorbed onto Si-H and formed high-quality monolayers with a binding density of 50-60% Si(111) surface atoms. Molecular dynamics simulations suggest that the binding proximity is close enough to allow efficient π-π interactions and therefore distinctly different packing and ring orientations for monomers with odd or even numbers of methylenes in their alkyl spacers. The odd-even alternation in molecular tilt was experimentally confirmed by contact angle, ellipsometry, FT-IR, and XPS with a close quantitative match to the simulation results. The orientations of both the ring plane and the long axis of the alkyl spacer are more perpendicular to the substrate plane for molecules with an even number of methylenes than for those with an odd number of methylenes. Interestingly, those with an even number conduct better than the effectively thinner monolayers of the molecules with the odd number of methylenes. We attribute this to a change in the orientation of the electron density on the aromatic rings with respect to the shortest tunneling path, which increases the barrier for electron transport through the odd monolayers. The high sensitivity of molecular charge transport to the orientation of an aromatic moiety might be relevant to better control over the electronic properties of interfaces in organic electronics. |
| تدمد: | 1520-5827 0743-7463 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f6353bf3aa12a51199b4c9b0d68dc169 https://doi.org/10.1021/la503536f |
| رقم الأكسشن: | edsair.doi.dedup.....f6353bf3aa12a51199b4c9b0d68dc169 |
| قاعدة البيانات: | OpenAIRE |
Find this issue from the American Chemical Society | تدمد: | 15205827 07437463 |
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