Solids full of holes: Crux of a Nobel find

It is like piecing together a Lego structure, but with molecular components. Metal-organic frameworks, or MOFs, the subject of the research behind this year's Nobel Prize for Chemistry, are a class of materials built with clusters of metal ions, connected through organic linkersand with vast, useful spaces in between.

- Kabir Firaque

A real-estate agent, for example, may describe one kind of MOF as "an attractive and very spacious studio apartment, specifically designed for your life as a water molecule", the Royal Swedish Academy of Sciences suggested on Wednesday while awarding the Nobel to Richard Robson (currently with the University of Melbourne), Susumu Kitagawa (Kyoto University) and Omar M Yaghi (University of Berkeley). Working separately, the three laid the foundations for this form of molecular architecture between the 1980s and the 2000s.

Researchers have used MOFs to harvest water from desert air, but that is by no means their only use. Laboratories around the world have used MOFs for extracting pollutants from water, capturing carbon dioxide, storing hydrogen, and catalysing reactions.

Early work

The idea struck Robson in the 1970s while building molecular models for his students, with wooden balls serving as atoms bonded together. What would happen, he wondered, if he linked together different types of molecules rather than atoms? It took him over a decade before he came up with his first such structure, inspired by the structure of a diamond, but in place of carbon atoms he used copper ions connected with an organic group (nitrile), a regular crystalline structure with a vast number of cavities.