title: Towards Redox-Driven Unidirectional Molecular Motion.
abstract: Redox-driven molecular motion is an attractive alternative to light-driven processes. Here, the ability of an overcrowded alkene-based unimolecular light-driven rotary motor (A) to be driven by oxidation/reduction cycles is explored. We show that two-electron oxidation of A is followed by irreversible deprotonation and reduction to form a monocationic species D(+) , in which the stereogenic center is lost. This latter species was isolated through preparative electrolysis and its structure was confirmed by using single-crystal X-ray analysis. However, at short timescales and in the absence of Brønsted acids, these processes can be outrun and the oxidation of A to a dicationic species B(2+) occurs, in which the central double bond (the axle of the molecular motor) becomes a single bond; when followed by rapid reduction, it results in the reformation of A, potentially in both its stable and unstable conformations. The latter conformation, if formed, undergoes thermal helix inversion, completing a rotary cycle. The data obtained regarding these reactions provide a window of opportunity for the motor to be driven electrochemically, without degradation from chemical reactions of the oxidized motor.
authors: Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of Groningen, Nijenborgh 4, 9747 AG, The Netherlands.
authors: Hella
authors: H
authors: Logtenberg
authors: Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of Groningen, Nijenborgh 4, 9747 AG, The Netherlands.
authors: Jetsuda
authors: J
authors: Areephong
authors: Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of Groningen, Nijenborgh 4, 9747 AG, The Netherlands.
authors: Jurica
authors: J
authors: Bauer
authors: Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of Groningen, Nijenborgh 4, 9747 AG, The Netherlands.
authors: Auke
authors: A
authors: Meetsma
authors: Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of Groningen, Nijenborgh 4, 9747 AG, The Netherlands.
authors: Ben L
authors: 0000-0003-0588-8435
authors: BL
authors: Feringa
authors: Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of Groningen, Nijenborgh 4, 9747 AG, The Netherlands. w.r.browne@rug.nl.
authors: Wesley R
authors: 0000-0001-5063-6961
authors: WR
authors: Browne
keywords: cyclic voltammetry; electrochemistry; electrochromism; molecular switching; photochromism