Phosphitebased

Phosphite-based compounds refer to materials and reagents that incorporate phosphite groups, derived from phosphorous acid (HPO3) or its esters. The term covers two broad classes: organophosphite esters with the structure P(OR)3 and inorganic or organometallic phosphites that contain PO3 units coordinated to metals. In organophosphites, phosphorus is in the +3 oxidation state, whereas many inorganic phosphites involve metal–phosphite motifs or framework structures. Phosphites are distinct from phosphates, which contain phosphorus in the +5 oxidation state.

Organophosphite esters are widely used as stabilizers and antioxidants in polymers. They scavenge radicals and decompose hydroperoxides formed during polymer processing, helping to prevent degradation and discoloration. They also serve as ligands in homogeneous catalysis and as reducing agents in certain organic syntheses. In coordination chemistry and materials science, phosphite ligands can influence metal center reactivity and selectivity.

Inorganic and metal phosphites appear in a variety of materials, including salts and framework-like structures where PO3 units connect metal centers. These phosphite-based materials can be of interest for catalysis, solid-state chemistry, and as precursors to more complex phosphorus-containing materials. The properties of phosphite-based compounds are influenced by the nature of the phosphite group, the surrounding ligands or framework, and the oxidation state of phosphorus.

Safety and handling depend on specific compounds; many organophosphites are moisture-sensitive and may be irritants or toxic in higher exposures. See also phosphate chemistry and phosphite ligands.