1. Periodically Twisted Molecular Wires Based on a Fused Unit for Efficient Intramolecular Hopping Transport
- Author
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Asakawa, Ryo, Yokoyama, Soichi, Yamada, Ryo, Maeda, Seiya, Ohto, Tatsuhiko, Tada, Hirokazu, and Ie, Yutaka
- Abstract
Realizing efficient long-distance intramolecular charge transport based on a hopping mechanism is a key challenge in molecular electronics. In hopping transport, a smaller reorganization energy (λ) and energy difference between hopping sites (ΔEhs) should lead to a smaller activation energy and faster charge transfer. However, the development of π-extended molecules that meet these requirements is challenging. In this study, we successfully synthesized several nanometer-scale π-extended molecules composed of a fused π-conjugated unit as a hopping site for reducing λ. Conformational twists between fused units effectively localize π-conjugation in each unit, contributing to reducing ΔEhs. The expected electronic structures of the oligomers were confirmed using spectroscopic and electrochemical measurements. Single-molecule conductance measurements exhibited higher conductance and lower activation energy than those of nonfused oligothiophenes. First-principles calculations indicated that smaller λ and ΔEhsvalues explain the high conductance. These results highlight the efficiency of the proposed molecular design for effective intramolecular hopping transport.
- Published
- 2024
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