Final published version
Licence: CC BY: Creative Commons Attribution 4.0 International License
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Unusual Length Dependence of the Conductance in Cumulene Molecular Wires
AU - Xu, W.
AU - Leary, E.
AU - Hou, S.
AU - Sangtarash, S.
AU - González, M.T.
AU - Rubio-Bollinger, G.
AU - Wu, Q.
AU - Sadeghi, H.
AU - Tejerina, L.
AU - Christensen, K.E.
AU - Agraït, N.
AU - Higgins, S.J.
AU - Lambert, C.J.
AU - Nichols, R.J.
AU - Anderson, H.L.
PY - 2019/6/17
Y1 - 2019/6/17
N2 - Cumulenes are sometimes described as “metallic” because an infinitely long cumulene would have the band structure of a metal. Herein, we report the single-molecule conductance of a series of cumulenes and cumulene analogues, where the number of consecutive C=C bonds in the core is n=1, 2, 3, and 5. The [n]cumulenes with n=3 and 5 have almost the same conductance, and they are both more conductive than the alkene (n=1). This is remarkable because molecular conductance normally falls exponentially with length. The conductance of the allene (n=2) is much lower, because of its twisted geometry. Computational simulations predict a similar trend to the experimental results and indicate that the low conductance of the allene is a general feature of [n]cumulenes where n is even. The lack of length dependence in the conductance of [3] and [5]cumulenes is attributed to the strong decrease in the HOMO–LUMO gap with increasing length.
AB - Cumulenes are sometimes described as “metallic” because an infinitely long cumulene would have the band structure of a metal. Herein, we report the single-molecule conductance of a series of cumulenes and cumulene analogues, where the number of consecutive C=C bonds in the core is n=1, 2, 3, and 5. The [n]cumulenes with n=3 and 5 have almost the same conductance, and they are both more conductive than the alkene (n=1). This is remarkable because molecular conductance normally falls exponentially with length. The conductance of the allene (n=2) is much lower, because of its twisted geometry. Computational simulations predict a similar trend to the experimental results and indicate that the low conductance of the allene is a general feature of [n]cumulenes where n is even. The lack of length dependence in the conductance of [3] and [5]cumulenes is attributed to the strong decrease in the HOMO–LUMO gap with increasing length.
KW - break junctions
KW - conductance
KW - cumulenes
KW - molecular wires
KW - single-molecule studies
KW - Electric conductance
KW - Molecules
KW - Nanowires
KW - Break junctions
KW - Computational simulation
KW - Cumulenes
KW - Length dependence
KW - Molecular conductance
KW - Molecular wires
KW - Single molecule conductance
KW - Single-molecule studies
KW - Hydrocarbons
U2 - 10.1002/anie.201901228
DO - 10.1002/anie.201901228
M3 - Journal article
VL - 58
SP - 8378
EP - 8382
JO - Angewandte Chemie International Edition
JF - Angewandte Chemie International Edition
SN - 1433-7851
IS - 25
ER -