Autonomous Dynamic Control of Crown Ether Cargo Release from [2]Rotaxane Carriers in a Piperidine Oscillator.

Chemical oscillations play a fundamental role in biological systems, yet their synthetic counterparts remain challenging to implement with functional outputs. Here, we report a piperidine-based chemical oscillator that autonomously drives periodic cleavage of a [2]rotaxane carrier, leading to controlled cargo release. The system operates through self-sustained oscillations, triggering rotaxane cleavage and the release of a crown ether cargo. Crown ethers were selected for their reactivity distinct from piperidine, while Fmoc-protected benzylamine rotaxane structures allowed for straightforward carrier modification. For all tested carriers, a piperidine pulse is present and occurs simultaneously with carrier cleavage, yielding up to 95% cargo release. Under flow conditions, periodic cargo release was sustained without extensive reoptimization, demonstrating the robustness of the system. Additionally, by adjusting space velocity, trigger concentration, and inhibitor levels, the oscillation period was varied by up to 2.5 h, with cargo release amplitude changing more than 3-fold. This work demonstrates the potential of catalytic oscillators to regulate downstream processes, paving the way toward construction of complex dynamic chemical systems.