Guaninium dihydrogenphosphite dihydrate

The structure of the title compound, C5H6N5O+·H2PO3−·2H2O, consists of a layer arrangement in which the organic cations are sandwiched between H2PO3− inorganic sheets. In the crystal structure, the phosphite anions are linked together by short strong (P—O—H⋯O—P) hydrogen bonds to form a two-dimensional network. Strong hydrogen bonds are responsible for the cohesion between organic–inorganic layers and maintain the stability of the structure.