Xu, W. and Leary, E. and Hou, S. and Sangtarash, S. and González, M.T. and Rubio-Bollinger, G. and Wu, Q. and Sadeghi, H. and Tejerina, L. and Christensen, K.E. and Agraït, N. and Higgins, S.J. and Lambert, C.J. and Nichols, R.J. and Anderson, H.L. (2019) Unusual Length Dependence of the Conductance in Cumulene Molecular Wires. Angewandte Chemie International Edition, 58 (25). pp. 8378-8382. ISSN 1433-7851
Full text not available from this repository.Abstract
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.