An artificial molecular pump

Cheng, Chuyang; McGonigal, Paul R.; Schneebeli, Severin T.; Li, Hao; Vermeulen, Nicolaas A.; Ke, Chenfeng; Stoddart, J. Fraser

Abstract

Carrier proteins consume fuel in order to pump ions or molecules across cell membranes, creating concentration gradients. Their control over diffusion pathways, effected entirely through noncovalent bonding interactions, has inspired chemists to devise artificial systems that mimic their function. Here, we report a wholly artificial compound that acts on small molecules to create a gradient in their local concentration. It does so by using redox energy and precisely organized noncovalent bonding interactions to pump positively charged rings from solution and ensnare them around an oligomethylene chain, as part of a kinetically trapped entanglement. A redox-active viologen unit at the heart of a dumbbell-shaped molecular pump plays a dual role, first attracting and then repelling the rings during redox cycling, thereby enacting a flashing energy ratchet mechanism with a minimalistic design. Our artificial molecular pump performs work repetitively for two cycles of operation and drives rings away from equilibrium toward a higher local concentration.

Citation

Cheng, C., McGonigal, P. R., Schneebeli, S. T., Li, H., Vermeulen, N. A., Ke, C., & Stoddart, J. F. (2015). An artificial molecular pump. Nature Nanotechnology, 10(6), 547-553. https://doi.org/10.1038/nnano.2015.96

• Journal Article Type: Article
• Acceptance Date: Apr 10, 2015
• Online Publication Date: May 18, 2015
• Publication Date: 2015
• Deposit Date: Sep 14, 2015
• Journal: Nature Nanotechnology
• Print ISSN: 1748-3387
• Electronic ISSN: 1748-3395
• Publisher: Nature Research
• Peer Reviewed: Peer Reviewed
• Volume: 10
• Issue: 6
• Pages: 547-553
• DOI: https://doi.org/10.1038/nnano.2015.96