Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Gating of Quantum Interference in Molecular Junctions by Heteroatom Substitution
AU - Liu, Xunshan
AU - Sangtarash, Sara
AU - Reber, David
AU - Zhang, Dan
AU - Sadeghi, Hatef
AU - Shi, Jia
AU - Xiao, Zong-Yuan
AU - Hong, Wenjing
AU - Lambert, Colin J.
AU - Liu, Shi-Xia
N1 - © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
PY - 2017/1/2
Y1 - 2017/1/2
N2 - To guide the choice of future synthetic targets for single-molecule electronics, qualitative design rules are needed, which describe the effect of modifying chemical structure. Here the effect of heteroatom substitution on destructive quantum interference (QI) in single-molecule junctions is, for the first time experimentally addressed by investigating the conductance change when a "parent" meta-phenylene ethylene-type oligomer (m-OPE) is modified to yield a "daughter" by inserting one nitrogen atom into the m-OPE core. We find that if the substituted nitrogen is in a meta position relative to both acetylene linkers, the daughter conductance remains as low as the parent. However, if the substituted nitrogen is in an ortho position relative to one acetylene linker and a para position relative to the other, destructive QI is alleviated and the daughter conductance is high. This behavior contrasts with that of a para-connected parent, whose conductance is unaffected by heteroatom substitution. These experimental findings are rationalized by transport calculations and also agree with recent "magic ratio rules", which capture the role of connectivity in determining the electrical conductance of such parents and daughters.
AB - To guide the choice of future synthetic targets for single-molecule electronics, qualitative design rules are needed, which describe the effect of modifying chemical structure. Here the effect of heteroatom substitution on destructive quantum interference (QI) in single-molecule junctions is, for the first time experimentally addressed by investigating the conductance change when a "parent" meta-phenylene ethylene-type oligomer (m-OPE) is modified to yield a "daughter" by inserting one nitrogen atom into the m-OPE core. We find that if the substituted nitrogen is in a meta position relative to both acetylene linkers, the daughter conductance remains as low as the parent. However, if the substituted nitrogen is in an ortho position relative to one acetylene linker and a para position relative to the other, destructive QI is alleviated and the daughter conductance is high. This behavior contrasts with that of a para-connected parent, whose conductance is unaffected by heteroatom substitution. These experimental findings are rationalized by transport calculations and also agree with recent "magic ratio rules", which capture the role of connectivity in determining the electrical conductance of such parents and daughters.
KW - Journal Article
U2 - 10.1002/anie.201609051
DO - 10.1002/anie.201609051
M3 - Journal article
C2 - 27897363
VL - 56
SP - 173
EP - 176
JO - Angewandte Chemie International Edition
JF - Angewandte Chemie International Edition
SN - 1433-7851
IS - 1
ER -