Efficient conducting channels formed by the ð-ð stacking in single [2,2]paracyclophane molecules
Citation:
Meilin Bai, Jinghong Liang, Liqiang Xie, Stefano Sanvito, Bingwei Mao and Shimin Hou, Efficient conducting channels formed by the ð-ð stacking in single [2,2]paracyclophane molecules, Journal of Chemical Physics, 136, 10, 2012, 104701-Download Item:
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Abstract:
The electronic transportproperties of single [2,2]paracyclophane molecules directly connected to gold and platinumelectrodes have been investigated both theoretically and experimentally by using first-principles quantum transport simulations and break-junction experiments. For comparison, investigations on [3,3]- and [4,4]-paracyclophanes have also been performed. Our calculations show that the strength of the ?-? interaction in paracyclophanes is critically dependent on the inter-ring distance. In contrast to [4,4]paracyclophane in which the ?-? interaction is very weak due to the large inter-ring distance, the ?-? interaction in [2,2]- and [3,3]-paracyclophanes is rather strong and dominates the electronic transportproperties. In particular, for the asymmetric Au-[2,2]paracyclophane-Au junction in which the [2,2]paracyclophane molecule is connected to each goldelectrode through a Au adatom and the two Au adatoms are attached in ?1-fashion to two carbon atoms in the benzene backbones connecting with different ethylene groups, the transmission coefficient at the Fermi level is calculated to be 1.0 ? 10?2, in excellent agreement with experiments. When the goldelectrodes are replaced by platinum, the calculated transmission coefficient at the Fermi level of the symmetric Pt-[2,2]paracyclophane-Pt junction with one Pt adatom used as the linker group is increased to 0.83, demonstrating that the ?-? stacking in [2,2]paracyclophane is efficient for electron transport when the molecule-electrode interfaces are electronically transparent. This is confirmed by our preliminary experimental studies on the Pt-[2,2]paracyclophane-Pt junctions, for which the low-bias junction conductance has reached 0.40 ? 0.02 G0 (G0 is the conductance quantum). These findings are helpful for the design of molecular electronic devices incorporating ?-? stacking molecular systems
Sponsor
Grant Number
Science Foundation Ireland (SFI)
G20267
National Natural Science Foundation of China (60703033).
61071012
National Natural Science Foundation of China (60703033).
20973141
Science Foundation Ireland (SFI)
07/IN.1/I945
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http://people.tcd.ie/sanvitosDescription:
PUBLISHED
Author: SANVITO, STEFANO
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Journal ArticleCollections:
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Journal of Chemical Physics136
10
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PhysicsSubject (TCD):
Nanoscience & MaterialsDOI:
http://dx.doi.org/10.1063/1.3692184Licences: