Credit: AM. CHEM. SOC.

J. Am. Chem. Soc. 131, 2159–2171 (2009); J. Am. Chem. Soc. 131, 3625–3627 (2009)

Metal–organic frameworks (MOFs) are porous materials with large surface areas that are made up of metals linked through organic groups. They are the focus of research for a range of applications, including hydrogen storage.

Martin Schröder at the University of Nottingham, UK, and his colleagues investigated which parts of a series of copper-based MOFs (one of which is pictured, above) were responsible for increasing the hydrogen-trapping ability of the materials. They showed that the shape of the linking groups and of the other chemical groups around the copper atoms were important. Bare copper sites held on to hydrogen the strongest. Pore size also affected how much hydrogen could be stored. One of the team's materials was able to store 7.78% by weight of hydrogen.

Another study from Anthony Cheetham at the University of Cambridge, UK, and his colleagues, showed that it is possible to make a multiferroic MOF — a material with more than one unique magnetic property. Multiferroic materials are hard to come by because they require the material to take on different molecular arrangements. But the team created a multiferroic MOF from manganese and organic groups, which might be used as magnetic-field sensors and in other devices.