Unusual Length Dependence of the Conductance in Cumulene Molecular Wires

Xu, Wenjun, Leary, Edmund, Hou, Songjun, Sangtarash, Sara, Teresa Gonzalez, M, Rubio-Bollinger, Gabino, Wu, Qingqing, Sadeghi, Hatef, Tejerina, Lara, Christensen, Kirsten E
et al (show 5 more authors) (2019) Unusual Length Dependence of the Conductance in Cumulene Molecular Wires. ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 58 (25). pp. 8378-8382.

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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.

Item Type: Article
Uncontrolled Keywords: break junctions, conductance, cumulenes, molecular wires, single-molecule studies
Depositing User: Symplectic Admin
Date Deposited: 13 Jun 2019 13:32
Last Modified: 19 Jan 2023 00:40
DOI: 10.1002/anie.201901228
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3045704