The directed motion of species against a chemical potential gradient is a fundamental feature of living systems, underpinning processes that range from transport through cell membranes to neurotransmission. The development of artificial active cargo transport could enable new modes of chemical purification and pumping. Here, a heat engine is described that drives chemical cargo between liquid phases to generate a concentration gradient. The heat engine, composed of a functionalized FeII 4 L4 coordination cage, is grafted with oligoethylene glycol imidazolium chains. These chains undergo a conformational change upon heating, causing the cage and its cargo to reversibly transfer between aqueous and organic phases. Furthermore, sectional heating and cooling allow for the cage to traverse multiple phase boundaries, allowing for longer-distance transport than would be possible using a single pair of phases.

中文翻译：

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热机驱动FeII 4 L4笼和货物的运输。

物种针对化学势梯度的定向运动是生命系统的基本特征，它支持从细胞膜转运到神经传递的过程。人工主动货物运输的发展可以实现化学提纯和抽水的新模式。在此，描述了一种热机，该热机在液相之间驱动化学货物以产生浓度梯度。由功能化的FeII 4 L4配位笼组成的热机上接有低聚乙二醇咪唑鎓链。这些链在加热时发生构象变化，从而使笼子及其货物在水相和有机相之间可逆地转移。此外，分段加热和冷却使笼子可以穿越多个相界，