title: Three-State Single-Molecule Naphthalenediimide Switch: Integration of a Pendant Redox Unit for Conductance Tuning.
abstract: We studied charge transport through core-substituted naphthalenediimide (NDI) single-molecule junctions using the electrochemical STM-based break-junction technique in combination with DFT calculations. Conductance switching among three well-defined states was demonstrated by electrochemically controlling the redox state of the pendent diimide unit of the molecule in an ionic liquid. The electrical conductances of the dianion and neutral states differ by more than one order of magnitude. The potential-dependence of the charge-transport characteristics of the NDI molecules was confirmed by DFT calculations, which account for electrochemical double-layer effects on the conductance of the NDI junctions. This study suggests that integration of a pendant redox unit with strong coupling to a molecular backbone enables the tuning of charge transport through single-molecule devices by controlling their redox states.
authors.affiliation: Organic Solids Laboratory, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China).
authors.forename: Yonghai
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern (Switzerland).
authors.forename: Masoud
authors.initials: M
authors.lastname: Baghernejad
authors.affiliation: Department of Physics, Lancaster University, Lancaster LA1 4YB (UK).
authors.forename: Al-Galiby
authors.initials: AG
authors.lastname: Qusiy
authors.affiliation: Department of Physics, Lancaster University, Lancaster LA1 4YB (UK).
authors.forename: David
authors.initials: D
authors.lastname: Zsolt Manrique
authors.affiliation: Organic Solids Laboratory, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China).
authors.forename: Guanxin
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern (Switzerland).
authors.forename: Joseph
authors.initials: J
authors.lastname: Hamill
authors.affiliation: Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern (Switzerland).
authors.forename: Yongchun
authors.initials: Y
authors.lastname: Fu
authors.affiliation: Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern (Switzerland).
authors.forename: Peter
authors.initials: P
authors.lastname: Broekmann
authors.affiliation: Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern (Switzerland). hong@dcb.unibe.ch.|Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China). hong@dcb.unibe.ch.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Hong
authors.affiliation: Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern (Switzerland).
authors.forename: Thomas
authors.initials: T
authors.lastname: Wandlowski
authors.affiliation: Organic Solids Laboratory, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China). dqzhang@iccas.ac.cn.
authors.forename: Deqing
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Department of Physics, Lancaster University, Lancaster LA1 4YB (UK). c.lambert@lancaster.ac.uk.
authors.forename: Colin
authors.initials: C
authors.lastname: Lambert
keywords: break junction; electrochemical gating; molecular electronics; naphthalenediimide; single molecule studies