Diheterabenzenes Containing Heavier Group 15 Elements

The incorporation of heavier main group elements into aromatic frameworks offers a powerful strategy for modifying the electronic structure, bonding, and reactivity of conventional cyclic-π-conjugated systems. Of particular interest are dipnictabenzenes, in which two CH units of an aromatic framework are replaced by heavier group 15 elements. These compounds provide distinctive platforms for exploring the interplay between aromatic stabilization, increasingly diffuse np orbital interactions, structural distortion, and open-shell character. Although early studies focused predominantly on diphosphinines, substantial advances over the past decade have enabled the synthesis and structural characterization of a broader range of heavier dipnictabenzene systems, including fused 1,4-diphosphinines and their heavier arsenic- and antimony-containing congeners. This mini-review surveys the development of this rapidly evolving field, encompassing theoretical investigations of the structures, relative stabilities, and aromaticity of dipnictabenzenes, synthetic approaches to isolable dipnictabenzene frameworks, and their characteristic reactivity. Particular emphasis is placed on the roles of ring fusion, electronic perturbation, and steric protection in stabilizing otherwise highly reactive species. Collectively, these studies reveal dipnictabenzenes as versatile and still largely unexplored cyclic-π-conjugated platforms with considerable potential for the discovery of unconventional bonding motifs, reactivity, and functional molecular properties.