Researchers at the University of Gothenburg have created a carbon material with a three-dimensional structure. The material, named diamondiyne, can be described as a porous diamond with the same basic shape as a tetrahedron.
The 2025 Nobel Prize in Chemistry was awarded for the development of new porous materials made from carbon-based molecules and metal ions, known as MOFs.
At the University of Gothenburg, Professor Karl Börjesson's research team has long been interested in creating porous materials without metal ions, in which carbon-based molecules, without metals bind together to form what are known as COFs.
Model in theory
It was during this work that they succeeded in bonding carbon atoms to one another through triple bonds, creating the carbon allotrope diamondiyne for the first time in the world.
"It has taken us an incredibly long time, but we finally succeeded. I am very pleased," says Karl Börjesson, Professor of Physical Chemistry at the University of Gothenburg.
A colleague told Karl Börjesson about a website where theoretical chemists have listed the carbon allotropes that should be possible to create – an almost infinitely long list. An allotrope is a chemical substance consisting of only one type of atom. Diamonds and graphite are examples of allotropes of carbon. Diamondiyne is a tetrahedral carbon allotrope that was first described theoretically 35 years ago.
Porous structure
Diamondiyne is created using relatively inexpensive equipment, with the material forming as a thin film where two liquids meet. Diamondiyne crystallises with the carbon atoms arranged as tetrahedras connected corner to corner in all three dimensions.
"The structure creates voids between the tetrahedra. The carbon allotrope can therefore be compared to a porous diamond. But unlike diamonds, diamondiyne does not require high pressure to make the carbon atoms bond to one another," says Karl Börjesson.
The crystal structure has been confirmed using electron microscopy at Stockholm University, although only in patches on the surface of the film. There are many things that can go wrong and prevent the carbon atoms from forming diamondiyne.
Nobelprize awarded allotropes
"We have at least managed to produce repeating patterns of diamondiyne in a volume measuring 10 nanometres on each side, 10 × 10⁻⁹ metres, and the images of the patterns correspond well with the theoretical models," says Karl Börjesson.
For a long time, physical carbon allotropes were limited to diamond, graphite and the three artificially produced carbon allotropes fullerene, carbon nanotubes and graphene. In recent years, a large number of new allotropes have been created, but never before one with a three-dimensional structure.
The development of both graphene and fullerene has been recognised with Nobel Prizes, largely because the very idea that these materials could exist was new.
"We will now investigate the properties of diamondiyne and how it might be used. One exciting aspect of the porous structure is that several diamondiyne structures could potentially be interwoven through each other's voids," says Karl Börjesson.
The study, now published in the prominent journal Angewandte Chemie, is a collaboration between Karl Börjesson's research group and colleagues at Stockholm University and Chalmers University of Technology.
