Phosphorus radicals and radical ions.

The synthesis and characterization of isolable radicals of main-group elements have been a long-pursued quest. Although there has been considerable progress in this area, particularly in isolating carbon radicals, the isolation of radicals comprising heavier p-block elements is still scarce. Among heavier p-block elements, the radical chemistry involving silicon and phosphorus is explored considerably. This review focuses on isolable phosphorus-centered radicals. Most of the compounds described here have been characterized by single-crystal X-ray analysis and EPR spectroscopy. The cyclic voltammetry study revealed interesting redox chemistry for many of these compounds. Here, we described the synthesis and properties of the radicals and radical ions comprising the phosphorus center.