Unusual Length Dependence of the Conductance in Cumulene Molecular Wires
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...
| Autores: | , , , , , , , , , , , , , , |
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| Tipo de documento: | artigo |
| Data de publicação: | 2019 |
| País: | España |
| Recursos: | Universidad Autónoma de Madrid |
| Repositório: | Biblos-e Archivo. Repositorio Institucional de la UAM |
| Idioma: | inglês |
| OAI Identifier: | oai:repositorio.uam.es:10486/691006 |
| Acesso em linha: | http://hdl.handle.net/10486/691006 https://dx.doi.org/10.1002/anie.201901228 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Break junctions Conductance Cumulenes Molecular wires Single-molecule studies Física |
| Resumo: | 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 |
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