An artificial molecular pump

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

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


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.

Original languageEnglish
Pages (from-to)547-553
Number of pages7
JournalNature Nanotechnology
Issue number6
Publication statusPublished - 6 Jun 2015

Bibliographical note

Funding Information:
This material is based on work supported by the National Science Foundation (NSF; CHE-1308107). The authors acknowledge the Integrated Molecular Structure Education and Research Center at Northwestern University for providing access to equipment for relevant experiments. The authors acknowledge the QUEST High-Performance Computing Cluster at Northwestern University for a research allocation of computer time. S.T.S. thanks the International Institute for Nanotechnology (IIN) at Northwestern University for a postdoctoral fellowship.

Publisher Copyright:
© 2015 Macmillan Publishers Limited.

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