hypophosphoric

Hypophosphoric refers to a chemical oxidation state of phosphorus that is lower than that in phosphoric acid. Specifically, it describes compounds where phosphorus is in the +3 oxidation state. The most common compound exhibiting this state is hypophosphorous acid, H3PO2, also known as phosphinic acid. This acid is a strong reducing agent and a monoprotic acid, meaning it donates only one proton.

Hypophosphorous acid and its salts, hypophosphites, are used in various applications. They are employed as reducing agents in chemical synthesis, for example, in the electroless plating of metals like nickel and copper. Hypophosphites also find use as antioxidants and stabilizers in certain industrial processes and polymers. The chemistry of hypophosphorous acid is distinct from that of phosphoric acid (where phosphorus is in the +5 oxidation state) and phosphorous acid (where phosphorus is in the +3 oxidation state but with a different structure and properties). The presence of a direct phosphorus-hydrogen bond in hypophosphorous acid is key to its reducing properties.