English
Swedish

Presented by Professor Olof Ramström
Member of the Royal Swedish Academy of Sciences
Member of the Nobel Committee for Chemistry

Your Majesties, Your Royal Highnesses,
Esteemed Nobel Prize Laureates, Honourable Colleagues,
Ladies and Gentlemen,

Consider the importance of holey materials. Porous structures that can be used for a large variety of purposes while accommodating smaller entities inside their cavities. How would one make the holes? Well, one may think of a subtractive manufacturing method, where material is removed to create the cavities. However effective, this may not be practical at the molecular scale, especially when the holes are nanometre-sized. A better method could be to use an additive manufacturing process. In this case, the holes would be indirectly formed by adding the materials surrounding them. Even better would be if the added building blocks could arrange themselves in a kind of programmed assembly process.

Doing this by means of chemistry at the molecular scale is very challenging. Nevertheless, this is what our laureates have developed and perfected – leading to what is called “metal–organic frameworks” or “MOFs”. For this, they adopted coordination chemistry, where metal-based nodes are linked together with organic (carbon-based) molecules.

Richard Robson produced, for example, a diamond-like material with spacious cavities based on the assembly between copper ions and tetratopic (4-armed) organic molecules. He also conceptualised the process and demonstrated the utility of such materials.

Susumu Kitagawa demonstrated gas adsorption as an important application. He made a tailored MOF that could take up – or release – gases, such as methane or nitrogen. Kitagawa also championed the development of flexible – or soft – frameworks. This led to controllable, shape-shifting materials, where the hole-structure can be varied upon demand.

Omar Yaghi demonstrated that stronger interactions between the building blocks led to greatly improved properties. For example, he developed an iconic MOF-structure – MOF-5 – which exhibited not only very high stability, but also a very large surface area!

The MOF contained thousands of square metres per gram, which showed that MOFs are competitive for industrial applications. Yaghi further conceptualised the field by demonstrating how a programmed assembly of MOFs can be made systematically. By varying the building blocks, large families of holey structures could be made with the same basic geometry (topology).

The accomplishments of our laureates have had an enormous impact on our society. Their remarkable chemistry has enhanced our capabilities and considerably widened and deepened our knowledge and understanding. As a consequence, the field has expanded rapidly, and many thousands of MOFs have now been developed. These frameworks have been tailored for a large variety of different applications, ranging from gas storage and carbon capture, to atmospheric water generation and drug delivery.

Susumu Kitagawa, Richard Robson and Omar Yaghi: You have made groundbreaking discoveries in chemistry that have led to the development of metal–organic frameworks. This is a truly great achievement for the benefit of humankind. On behalf of the Royal Swedish Academy of Sciences I wish to convey to you our warmest congratulations. May I now ask you to step forward and receive your Nobel Prizes from the hands of His Majesty the King.

Copyright © The Nobel Foundation 2025