Consistent zincophosphite 4-ring 'ladder' chain structural motif with isomeric ligands

The syntheses and crystal structures of four hydro-thermally prepared organo-zinc phosphites, viz. poly[[(2-amino-3-methyl-pyridine)-μ₃-phospho-nato-zinc] hemihydrate], {[Zn(HPO₃)(C₆H₈N₂)]·0.5H₂O} , (I), poly[(2-amino-4-methyl-pyridine)-μ₃-phospho-nato-zinc], [Zn(HPO₃)(C₆H₈N₂)] , (II), poly[(2-amino-5-methyl-pyridine)-μ₃-phospho-nato-zinc], [Zn(HPO₃)(C₆H₈N₂)] , (III), and poly[bis-(2-amino-4-methyl-pyridinium) [tetra-μ₃-phospho-nato-trizinc] monohydrate], {(C₆H₉N₂)₂[Zn₃(HPO₃)₄]·H₂O} , (IV), are described. Compounds (I)-(III) are constructed from vertex-sharing ZnO₃N tetra-hedra (the organic mol-ecule acting as a ligand) and HPO₃ pseudo pyramids in a 1:1 ratio to generate the same motif of infinite 4-ring 'ladder' chains propagating in the [010], [101] and [100] directions, respectively, whereas (IV) consists of (010) layers of vertex-sharing ZnO₄ and HPO₃ units in a 3:4 ratio with the protonated organic mol-ecule acting as a template. When an excess of HCl is used in the synthesis, the simple hydrated mol-ecular salt, bis-(2-amino-3-methyl-pyridinium) tetra-chloro-zincate monohydrate, (C₆H₈N₂)₂[ZnCl₄]·H₂O, (V), arises. Com-pounds (I)-(V) feature extensive networks of hydrogen bonds, both classical (N-H⋯O, N-H⋯Cl, O-H⋯O) and non-classical (C-H⋯O, C-H⋯Cl) in nature, which help to consolidate the extended structures.