Triethanolammonium dihydrogenphosphite

The title compound, [HN(C2H4OH)(3)](H2PO3) or C6H16NO3+ .H2PO3-, is isostructural with its hydrogenselenite congener and contains a network of partially disordered triethanolammonium cations and dihydrogenphosphite anions [for the latter species: d(av)(P-O) = 1.514 (2) Angstrom and theta(av)(O-P-O) = 111.9 (2)degrees]. The [H2PO3](-) units are linked into a polymeric chain by P-O-H...O-P hydrogen bonds along the polar [010] direction, with the chains crosslinked into (001) sheets by way of O-H...O bonds involving the organic species. Some C-H...O interactions may also be present [d(av)(H...O) = 2.45 Angstrom, theta(av)(C-H...O) = 158degrees and d(av)(C...O) = 3.364 (4) Angstrom]. The [HN(C2H4OH)(3)](+) cation contains a typical trifurcated intramolecular N-H...(O,O,O) hydrogen bond [d(av)(H...O) = 2.31 Angstrom and theta(av)(N-H...O) = 112.7degrees].