Chemical Fuel-Driven Networked Catalytic Machinery

Abstract

We present a pivotal advancement in networked molecular machinery by integrating chemical-fuel-driven communication and catalysis. When the self-sorted system of a zinc hexacyclen, a silver(I)-loaded receptor, and a [2]rotaxane (= NetState-I) was exposed to 2-cyano-2-phenylpropanoic acid as chemical fuel, the protonation first entailed a translocation of Zn²⁺ onto the receptor and, concomitantly, of silver(I) onto the [2]rotaxane, a cascade process that gradually reversed to the initial state. In the initial networked state, the silver(I) ions were tightly captured inside the receptor so that their catalytic activity was zero, while the transiently generated silver(I) [2]rotaxane (k₂₉₈ = 176 kHz) catalyzed the 6-endo cyclization of 2-alkynylbenzaldoxime. The pulsed operation of this networked catalytic machinery, driven by chemical fuel, presents a novel paradigm for cascaded signaling and time-programmed catalysis, mimicking the complexity of biological systems.

Keywords: chemical fuel; molecular machine; rotaxane; supramolecular chemistry; switchable catalysis.