Aromaticity rules

In 1931, Erich Huckel published a landmark paper - the seed of the now famous 4n + 2 rule for aromaticity in annulenes that bears his name. Electron counting has since been extended to other classes of compounds, resulting in a multitude of rules aiming to capture the concept of aromaticity and its impact in chemistry.

Automated summary

In 1931, Erich Huckel published a groundbreaking paper introducing the Huckel aromaticity rule, which has since become well-known. Electron counting has been applied to various classes of compounds, leading to the development of numerous rules aimed at capturing the concept of aromaticity and its significance in chemistry.