Breathing benzene

Friedrich Kekulé's apocryphal daydream of a tail-eating snake led him to the cyclic structure of the benzene molecule, the only way, he reasoned, that six carbon atoms and six hydrogen atoms could sit comfortably together and display the molecule's known properties. Chemists ever since have been fascinated by the benzene molecule whether the standalone compound or the ring embedded in millions of different compounds. However, it still continues to surprise and a new theoretical study by David Bean and Patrick Fowler of the University of Sheffield, UK, now reveals how the aromaticity of the molecule ebbs and flows as the ring breathes. Their discovery takes us another step closer to a full understanding of how aromaticity affects stability and the reactivity of the benzene ring.