Nordic Life Science 1
CHEMISTRY // MOFS efficient gas capture and stora
ge, catalysis, and even quantum devices.” Šimėnas has co-authored a scientific publication with one of the three laureates, Kitagawa, published in the Journal of Physical Chemistry in 2016. According to Šimėnas, working alongside such a prominent scientist while preparing the publication and obtaining the first results was an immensely rewarding experience for him as a young doctoral student. “If someone had asked me back then whether he would one day gain recognition from the Nobel Committee, I would have said a firm “yes” without hesitation,” he says. The discoveries The story of MOFs begins in 1974, when Richard Robson, who taught at the University of Melbourne, Australia, at the time, was going to drill holes in wooden balls to turn them into atom models. He needed to mark out where the different holes/bonds were to be located, depending on which atom it was, and he realized that the model molecules automatically had the correct form and structure, because of where the holes were situated. He wondered what would happen if he utilized the atoms’ inherent properties to link together different types of molecules, instead of individual atoms. Ten years later Robson tested his idea and combined positively charged copper ions with a four-armed molecule. When combined, they bonded to form a well-ordered, spacious crystal, describes the Royal Swedish Academy of Sciences. The ions’ and molecules’ inherent attraction to each other mattered, so they organized themselves into a large molecular construction. He published his findings in 1989, in the American Chemical Society, and shortly after that presented several new types of molecular constructions. He also demonstrated that substances could flow in and out of the construction and that it could be used to catalyze chemical reactions. However, the constructions were still quite rickety and unstable I n Japan, Susumu Kitagawa had also begun to create porous molecular structures. He presented his first construction in 1992, a two-dimensional material with cavities in which acetone molecules could hide. This was not so useful and it was unstable but it had resulted from a new way of thinking about the art of building with molecules, describes the Royal Swedish Academy of Sciences. The first breakthrough came in 1997 when Kitagawa and his team were able to create three-dimensional constructions that were intersected by open channels (using cobalt, nickel or zinc ions and 4,4’-bipyridine). When they dried one of these it was stable and the spaces could even be filled with gases. In 1998, Kitagawa presented his findings and the advantages of using these constructions, not least that they can form soft and flexible materials, in the Bulletin of the Chemical Society of Japan. Richard Robson was inspired by the structure of diamond, in which every carbon atom is linked to four others in a pyramid-like shape. Rather than carbon, he used copper ions and a molecule with four arms, each with a nitrile at the end. This is a chemical compound that is attracted to copper ions. When the substances were combined, they formed an ordered and very spacious crystal. NORDICLIFESCIENCE.ORG | 47 ILLUSTRATION ©JOHAN JARNESTAD/THE ROYAL SWEDISH ACADEMY OF SCIENCES