Chemists Have Just Tied the Tightest Knot Ever

In an unexpected discovery, scientists have unintentionally created the tiniest and tightest knot to date, earning a prestigious spot in the Guinness Book of World Records.

This extraordinary microscopic knot is made up of only fifty-four atoms, forming a unique ‘trefoil’ knot by being twisted three times. One important thing is that there are no loose ends in this intricate structure.

Picture it like a ‘three-leaf clover’ shape. This shape plays a crucial role in mathematical knot theory, according to ScienceAlert.

The previous record of 69 atom knots broken

In 2020, Chinese chemists skillfully guided a string of sixty-nine atoms to weave a trefoil knot by crossing over itself three times. Now, a collaborative effort between researchers at the University of Western Ontario in Canada and the Chinese Academy of Sciences has outperformed that previous record.

The strength of the molecular knot intensifies as the ratio of atoms to ‘back crossings’ decreases. The 2020 knot boasted a backbone crossing ratio (BCR) of 23.

In this latest achievement, the knot has an even more impressive BCR of 18, as reported by ScienceAlert.

Scientists create world's tiniest knot! 🪢Just 54 atoms long and features a trefoil shape with six gold atoms at its core. ⚛️Why is this important? It may not be but could hint at future innovations in materials science. 🔬Or it was pointless, but still cool imo. pic.twitter.com/ZeCWJYhVnX

— Intuition (@intuition_co) January 23, 2024

Typically, most organic molecular knots have a backbone crossing ratio (BCR) ranging from 27 to 33. The ongoing challenge for scientists is determining the smallest and tightest possible single-stranded knots.

Quantum chemical calculations propose that the most stable trefoil structure consists of about fifty molecules, bringing us closer to the theoretical limit.

This recent achievement marks a significant step forward, bringing experts closer to the microscopic knots naturally occurring in our DNA, RNA, and different proteins within our bodies.

Moreover, unraveling the formation of this latest knot holds promise for aiding scientists in the development of improved plastics and polymers, according to ScienceAlert.

Unexpected creation of a trefoil knot

The team of researchers points out that molecular knots, though challenging to synthesize, play crucial roles in shaping protein structures and influencing the properties of valuable molecular materials, which hinge on the size of the knotted structure.

Moreover, this discovery was quite incidental, as Richard Puddephatt, a chemist, explained to Alex Wilkins at New Scientist. Puddephatt and his colleagues were originally focused on producing metal acetylides in the lab.

These acetylides, a type of hydrocarbon with hydrogen removed from the end, prove highly beneficial for conducting organic chemical reactions.

During experiments, when connecting gold acetylide with another carbon structure known as a diphosphine ligand, the team stumbled upon an unexpected outcome, namely the formation of a trefoil knot. This was in place of the anticipated gold chain or catenane, according to ScienceAlert.