Reversible Multicomponent AND Gate Triggered by Stoichiometric Chemical Pulses Commands the Self-Assembly and Actuation of Catalytic Machinery.

The present work demonstrates the operation of a reversible supramolecular gate, i.e., an ensemble of various components linked by chemical communication, which is triggered by stoichiometric chemical inputs and by obeying the AND truth table delivers a stoichiometric chemical signal. The output triggers a series of events that finally set up a catalytic process. In detail, a three-component AND gate, composed of two distinct nanoswitches, a copper-loaded and an unloaded one {= state (0,0)}, was actuated with stoichiometric amounts of two inputs (IN-1 = Zn2+, IN-2 = Hg2+) generating copper(I) ions as output in state (1,1). The utility of this information processing was highlighted by using the copper(I) output for triggering the self-assembly of the four-component rotor ROT-2 through metal translocation. In the presence of suitable reactants, ROT-2 acted as a catalytic machinery catalyzing a click reaction (= signal amplification). Verification of the functioning of the AND gate in a mixture of 12 components was thus accomplished by monitoring formation of the click product. Due to the stoichiometric design, the gate was reset to state (0,0) by adding hexacyclen and reactivated by adding inputs IN-1 and IN-2 alike in the first cycle.