Aromaticity: One of chemistry’s most crucial concepts is in crisis – can we fix it?

In 1862, a chemist nodded off in entrance of a fireplace and commenced to dream. August Kekulé had been pondering probably the most urgent query in his subject on the time: what was the chemical construction of a curious compound known as benzene? As Kekulé slumbered, the atoms danced in his thoughts and organised themselves right into a imaginative and prescient of a snake consuming its personal tail. That was it! The carbon atoms of benzene have been joined collectively in a hoop.

It might not have fairly the drama of Archimedes working by means of the streets bare, however, in its personal manner, it was a eureka second. Benzene turned out to be the archetype of a compound with a property known as aromaticity, now recognised as among the many most necessary concepts in chemistry. As an alternative of normal bonds, fragrant molecules include dynamic, ring-shaped bonding that endows them with unimaginable stability and a raft of different useful properties. Two-thirds of recognized molecules are fragrant, together with elements of DNA and proteins, the constructing blocks of life.

Lately, although, the dream has become a nightmare. Now we have been discovering new sorts of aromaticity in every single place – to the purpose the place there are dozens of competing definitions. It might be one of the vital necessary ideas in chemistry, however nobody can agree on what it means any extra. It isn’t all unhealthy information, although. The confusion has prompted chemists to assume deeply about aromaticity and this has led to a raft of latest concepts about how we will put it to make use of.

Chemistry is the science of atoms, bonds and molecules and the craft of cajoling these molecules to react with one …