P,P′-Diphenylethylenediphosphinic acid dihydrate

The title compound, C14H16O4P2·2H2O, possesses a crystallographic inversion center where two –P(=O)(OH)(C6H5) groups are joined together via two –CH2 groups. In the crystal, the acid molecules are linked by the water molecules via O—H...O hydrogen bonds, leading to the formation of a two-dimensional network lying parallel to (101)