Phosphorine (IUPAC name: phosphinine) is a heavier element analog of pyridine, containing a phosphorus atom instead of an aza- moiety.

[3][4] In contrast, silabenzene, a related heavy-element analogue of benzene, is not only air- and moisture-sensitive but also thermally unstable without extensive steric protection.

The P-oxides are extremely unstable, rapidly adding nucleophiles to a species tetracoordinate at phosphorus.

Strongly backbonding Lewis acids (e.g. tungsten pentacarbonyl) can stabilize a dative bond from phosphorus.

[6] Unlike arsabenzene, phosphorine rarely participates in Diels-Alder-type cycloadditions; when it does, the coupling partner must be an extremely electron-poor alkyne.