Phosphorusoxygenphosphorus

Phosphorusoxygenphosphorus, also referred to as a phosphorus–oxygen–phosphorus (P–O–P) linkage, is a chemical motif in which two phosphorus atoms are connected by a single bridging oxygen. This P–O–P bridge is a central feature of many condensed phosphates and related organophosphorus compounds.

In structural terms, each phosphorus center in P–O–P motifs is typically in the +5 oxidation state and bonded to multiple oxygens. The bridging oxygen forms a link between two phosphate units, as seen in pyrophosphates (P2O7) and extended polyphosphate chains. The geometry around phosphorus can vary with substitution, but the characteristic feature is the oxygen atom that directly connects two phosphorus atoms.

Occurrence and significance: P–O–P bonds occur widely in chemistry and biology. In biology, pyrophosphate and nucleoside triphosphates such as ATP contain P–O–P linkages that are central to energy transfer and metabolic regulation; hydrolysis of these bonds releases energy used by cells. In inorganic chemistry and materials science, P–O–P bridges appear in solid-state phosphates and in various coordination or polymeric phosphor-oxide structures, contributing to the properties of fertilizers, glasses, and flame retardants.

Reactions and synthesis: The P–O–P linkage can be formed by condensation reactions between phosphate units (often with dehydration or activating reagents) and can be cleaved by hydrolysis under acidic or basic conditions. The bond is generally reactive toward nucleophiles, enabling conversion to individual phosphate units or to other phosphate esters.