[Zn3(HPO4)4](NMe4)2: a zincophosphate containing interruptions of isolated hydrogen-bonding [H–O(P)]4 groupings within a novel three-dimensional four-connected framework

The new zincophosphate [Zn3(HPO4)4](NMe4)2, I, has been synthesized hydrothermally, and the crystal structure was determined by single-crystal X-ray diffraction. Corner-sharing ZnO4 and PO3(OH) tetrahedra form zigzag ladder chains of edge-sharing 4-membered rings. These chains link into the anionic host framework that, formally, generates a three-dimensional system of intersecting channels bound by 16-membered rings, in which tetramethylammonium cations reside. However, the channels are partly blocked by hydrogen bonds in [H–O(P)]4 groupings. Formal substitution of the four H atoms in each grouping by a tetravalent cation results in a fully four-connected network of equal charge and novel topology that generates gismondine-type [4684] cavities at the intersections of 8-membered ring channels. I was further studied by variable-temperature powder X-ray diffraction, thermogravimetry, and FT-IR spectroscopy.