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Motor molecules marshaled in metal-organic framework

Molecular machines can already act as switches, shuttles, motors, or pumps, but most work only in solution, where it’s difficult to coordinate their activity. To help the minute gadgets perform useful work at everyday scales, chemists need to find ways to marshal their efforts. Now, a team led by Ben L. Feringa at the University of Groningen has built propeller-like molecular motors into the structure of a metal-organic framework (MOF) to create organized arrays. MOFs are molecular scaffolds containing metal-based nodes connected by organic-molecule struts, forming an extremely porous crystalline lattice. Feringa’s moto-MOFs contain about 3 × 1020 motor units per cubic centimeter, which turn in the same direction when exposed to ultraviolet light (Nat. Nanotechnol. 2019, DOI: 10.1038/s41565-019-0401-6). “It’s terrific, it’s quite an achievement,” says Stephen J. Loeb, a molecular machinist at the University of Windsor who was not involved in the research. The MOFs incorporate a molecular motor