title: A Divalent Pentastable Redox-Switchable Donor-Acceptor Rotaxane.
abstract: Donor-acceptor materials with small HOMO-LUMO gaps are important in molecular electronics, but are often difficult to synthesise. A simple and efficient way to position tetrathiafulvalene (TTF) as the donor and naphthalene diamide (NDI) as the acceptor in close proximity to each other in a divalent crown/ammonium pseudo[2]rotaxane is presented. The divalent design provides high chelate cooperativity and much stronger binding compared with a monovalent analogue. The pseudo[2]rotaxane was then doubly interlocked by stoppering it in a catalyst-free 1,3-dipolar cycloaddition. UV/Vis and cyclic voltammetry experiments with the resulting [2]rotaxane revealed the optoelectronic properties of an intramolecular charge transfer with a small HOMO-LUMO energy gap. Redox-switching experiments showed the rotaxane to be pentastable. DFT calculations provided insights into the electronic structures of the five redox states.
authors.affiliation: Institut für Chemie und Biochemie, Organische Chemie, Freie Universität Berlin, Takustraße 3, 14195, Berlin, Germany.
authors.forename: Hendrik V
authors.initials: HV
authors.lastname: Schröder
authors.affiliation: Institut für Chemie und Biochemie, Organische Chemie, Freie Universität Berlin, Takustraße 3, 14195, Berlin, Germany.
authors.forename: Henrik
authors.initials: H
authors.lastname: Hupatz
authors.affiliation: Institut für Chemie und Biochemie, Theoretische Chemie, Freie Universität Berlin, Takustraße 3, 14195, Berlin, Germany.
authors.forename: Andreas J
authors.initials: AJ
authors.lastname: Achazi
authors.affiliation: Institut für Chemie und Biochemie, Anorganische Chemie, Freie Universität Berlin, Fabeckstr. 34/36, 14195, Berlin, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Sobottka
authors.affiliation: Institut für Chemie und Biochemie, Anorganische Chemie, Freie Universität Berlin, Fabeckstr. 34/36, 14195, Berlin, Germany.
authors.forename: Biprajit
authors.initials: B
authors.lastname: Sarkar
authors.affiliation: Institut für Chemie und Biochemie, Theoretische Chemie, Freie Universität Berlin, Takustraße 3, 14195, Berlin, Germany.
authors.forename: Beate
authors.initials: B
authors.lastname: Paulus
authors.affiliation: Institut für Chemie und Biochemie, Organische Chemie, Freie Universität Berlin, Takustraße 3, 14195, Berlin, Germany.
authors.forename: Christoph A
authors.initials: CA
authors.lastname: Schalley
keywords: donor-acceptor systems; molecular devices; multivalency; redox chemistry; rotaxanes