Five‐Membered Aromatic and Antiaromatic Rings with Gallium, Germanium, and Bismuth Centers: A Short March through the Periodic Table

Criteria for aromaticity–a topic with staying power! Planarity of the rings, bonds of equal length, stabilization energies, and the number of π electrons were considered among the characteristics of the important phenomenon of aromaticity, but no one of these features is generally valid. Schleyer et al. (p. 334 in this issue) have now correlated the criteria with ab initio IGLO calculations on five‐membered heterocycles. In addition this highlight collates the synthesis methods and the chemical properties of these interesting compounds.