Title

From Static to Dynamic: Electron Density of HOMO at Biaryl Linkage Controls the Mechanism of Hole Delocalization

Document Type

Article

Language

eng

Publication Date

2018

Publisher

American Chemical Society

Source Publication

Journal of the American Chemical Society

Source ISSN

0002-7863

Abstract

In order to extend the physical length of hole delocalization in a molecular wire, chromophores of increasing size are often desired. However, the effect of size on the efficacy and mechanism of hole delocalization remains elusive. Here, we employ a model set of biaryls to show that with increasing chromophore size, the mechanism of steady-state hole distribution switches from static delocalization in biaryls with smaller chromophores to dynamic hopping, as exemplified in the largest system, tBuHBC2 (i.e., “superbiphenyl”), which displays a vanishingly small electronic coupling. This important finding is analyzed with the aid of Hückel molecular orbital and Marcus–Hush theories. Our findings will enable the rational design of the novel molecular wires with length-invariant redox/optical properties suitable for long-range charge transfer.

Comments

Journal of the American Chemical Society, Vol. 140, No. 14 (2018): 4765-4769. DOI.

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