Metal-organic frameworks (MOFs) are materials made of regularly spaced metallic clusters linked by long, thin organic molecules. The empty space in the resulting structure makes them useful: size the gaps right and a MOF can store large quantities of "guest" chemicals. As Heiner Linke, chair of the Nobel chemistry-prize committee, put it in 2025, they are like hotels for chemicals.
The field was pioneered by Richard Robson, who worked out how to make copper ions and tetracyanotetraphenylmethane self-assemble into a diamond-like crystalline structure with large cavities. Kitagawa Susumu helped convince the chemistry community that MOFs had big advantages over naturally occurring zeolites—minerals with similar gap-filled structures—in part by demonstrating that MOFs could be made flexible. Omar Yaghi made those possibilities real, creating MOF-5 in 1999, which boasts nearly 3,000 square metres of internal surface area per gram (compared with several hundred for zeolites) and is stable at temperatures up to 300°C.
Because MOFs are designed from scratch, their chemistry can be tweaked to target particular molecules. The near-infinite variety of organic chemistry means the linking molecules can be modified to do almost anything. Some MOFs have linkages that contain catalysts, meaning they can break down the substances they absorb into simpler components.
Researchers have created MOFs that can pull oil spills out of water, store large quantities of hydrogen or methane, remove PFAs from drinking water, cage drugs before releasing them at specific locations in the body, and absorb and enzymatically break down antibiotics in the environment. The work earned all three scientists the 2025 Nobel chemistry prize.
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