The title salt, C₄H₈N₃O⁺·H₂PO₃⁻, contains a creatininium cation (2-amino-1-methyl-4-oxo-4,5-di­hydro-1H-imidazol-3-ium) and a phosphite anion. The crystal packing shows planes of hydrogen-bonded ions parallel to the (-114) and (11-4) planes.

The effect of hydro­static compression on the crystal structure of glycinium phosphite is explored by single-crystal X-ray diffraction and DFT calculations and discussed in relation to a possible ferroelectric phase transition.

Two of the constituent mol­ecules in bis­(3-carbamoylpyridin-1-ium) phosphite monohydrate, i.e. the phosphite anion and the water mol­ecule, are situated on the symmetry plane. The mol­ecules are held together by moderate N—HO and O—HN, and weak O—HO and C—HO_carbon­yl hydrogen bonds in which the primary and secondary amine and water H atoms are involved. The H atom directly bonded to the P atom avoids hydrogen bonding, as usual.

The title compound is built up from CaO₇ polyhedra and HPO₃ pseudo tetra­hedra sharing corners and edges to generate a three-dimensional network.

The title substance of cerium(IV) bis­(phosphite), Ce(HPO₃)₂, crystallizes in a trigonal cell and is composed of CeO₆ octa­hedra and phosphite tetra­hedra.

The effects of radiation on the formation of the polar structure of ferroelectric glycinium phosphite is discussed together with the advantages and drawbacks of synchrotron experimentation with fine temperature sampling.

The new potential NLO (nonlinear optical) material L-argininium phosphite was obtained from a 1:1 solution of L-arginine and phospho­rous acid. The composition of the product obtained from the 1:2 solution is proposed on the basis of spectroscopic data.

The crystal structure of a rhodium complex containing fragments and rearrangement products of a hy­droxy phospho­nite is described.

In the presence of difluoromethane in pentane solvent, the scorpionate complex Tp'Rh[P(OMe)₃](Me)H loses methane to give a product in which the phosphine O-Me bond is cleaved.

The solution-mediated syntheses and crystal structures of catena-poly[bis­(2-amino-3-hy­droxy­pyridinium) [zinc-di-μ-phospho­nato] dihydrate], (I), and poly[(benzene-1,2-di­amine)(μ₅-phospho­nato)zinc], [Zn(HPO₃)(C₆H₈N₂)]_n, (II) are described. The extended structure of (I) features [010] anionic chains of vertex-sharing ZnO₄ tetra­hedra and HPO₃ pseudopyramids while that of of (II) features a direct Zn—N bond to the neutral 1,2-di­amino­benzene species as part of ZnO₃N tetra­hedra as well as HPO₃ pseudopyramids.