Long-Lived Radicals of the Heavier Group 15 Elements Arsenic, Antimony, and Bismuth

The syntheses and properties of long-lived arsenic, antimony, and bismuth-centered radicals are reviewed. In contrast to the rich phosphorus-based radical chemistry, that of the heavier congeners is far less advanced, which can be attributed to the increased instability of coordinatively and electronically unsaturated heavy main-group element centers. However, the development of new synthetic strategies and stabilization methods particularly in the last decade enabled the isolation and characterization of several unpaired electron-containing heavy group 15 element species featuring various structural motifs and electronic properties. The long-lived character of these radicals allowed for the elucidation of their electronic structures and bonding properties, as well as the exploration of their unique reactivity.