Template or ligand? Different structural behaviours of aromatic amines in combination with zincophosphite networks

The solution-mediated syntheses and crystal structures of catena-poly[bis­(2-amino-3-hy­droxy­pyridinium) [zinc-di-μ-phospho­nato] dihydrate], {(C₅H₇N₂O)[Zn(HPO₃)₂]·2H₂O}_n, (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; these chains are characterized by disorder over major [occupancy 0.7962 (13)] and minor [0.2038 (13)] components, which can be superimposed on each other by a nominal translational shift. The 2-amino-3-hy­droxy­pyridinium cations and water mol­ecules of crystallization inter­act with the ZnPO chains by way of numerous O—H⋯O and N—H⋯O hydrogen bonds. The structure 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. The Zn- and P-centred groupings are linked through their O-atom vertices into infinite (010) sheets and the structure is consolidated by N—H⋯O hydrogen bonds and N—H⋯π inter­actions. The crystal of (I) chosen for data collection was found to be an inversion twin in a 0.56 (2):0.44 (2) domain ratio.