Take into consideration a knot that is so minute that it is not visible to the human eye. The next step is to think even more narrowly.Chemists tied together just 54 atoms to create the tiniest molecular knot ever.
The knot is a chain of gold, phosphorus, oxygen, and carbon atoms that crosses itself three times, forming a pretzel shape known as a trefoil. This chain was described on January 2 in Nature Communications. The previous record for the smallest molecular knot, which was described in the year 2020, had 69 atoms.
Chemist Richard Puddephatt created the new knot by accident while working with colleagues at the Chinese Academy of Sciences in Dalian. They were seeking to construct intricate structures of interlocked ring molecules, also known as catenanes. Catenanes have the potential to be used in molecular machines, which are essentially switches and motors at the molecular scale. However, for the time being, scientists are still finding out how these machines function, which led to the production of something else by accident.
“It was just serendipity, one of those lucky moments in research that balances out all the hard knocks that you take,” says Puddephatt, who is affiliated with the University of Western Ontario in London, Canada.
In addition, the new trefoil knot is the most secure of its sort there is. The backbone crossing ratio, often known as the BCR, is the ratio that researchers use to determine the degree of tightness of a molecular knot. This ratio is obtained by dividing the number of atoms in the chain by the number of chain crossings. When the BCR is lower, the knot will be more tightly tied. It has a BCR of 18, which is the new knot. Prior to this, the trefoil knot that was tighter had a BCR of 23.
The investigation of microscopic molecular knots may one day result in the development of novel materials (SN: 8/27/18). On the other hand, for the time being, the group is still attempting to figure out why this particular arrangement of atoms results in a knot at all.