title: A toggle nanoswitch alternately controlling two catalytic reactions.
abstract: Reversible switching between two states of the triangular nanoswitch [Cu(1)](+) was accomplished by alternate addition of 2-ferrocenyl-1,10-phenanthroline (2) and copper(I) ions. The two switching states regulate the binding and release of two distinct catalysts, piperidine and [Cu(2)](+), in a fully interference-free manner and allow alternating on/off switching of two orthogonal catalytic processes. In switching state I, piperidine is released from the nanoswitch and catalyzes a Knoevenagel addition between 4-nitrobenzaldehyde and diethyl malonate (ON-1 and OFF-2), while in state II the released [Cu(2)](+) catalyzes a click reaction between 4-nitrophenylacetylene and benzylazide (OFF-1 and ON-2). Upon addition of one equivalent of 2 to the (OFF-1 and ON-2)-state, both catalytically active processes are shut down (OFF-1 and OFF-2).
authors.affiliation: Center of Micro and Nanochemistry and Engineering, Organische Chemie I, Universität Siegen, Adolf-Reichwein-Strasse 2, 57068 Siegen (Germany).
authors.forename: Soumen
authors.initials: S
authors.lastname: De
authors.forename: Susnata
authors.initials: S
authors.lastname: Pramanik
authors.forename: Michael
authors.initials: M
authors.lastname: Schmittel
keywords: homogeneous catalysis; host-guest systems; nanomechanics; orthogonal coordination; switching