(3,4)-Connected Zincophosphites as Structural Analogues of Zinc Hydrogen Phosphate

The synthesis and crystal structures of three new open-framework zincophosphites with helical channels are reported
here in the context of the synthetic design of an open architecture from three- and four-connected polyhedral
centers. These zincophosphites were prepared under hydrothermal conditions from HF-containing media in mixed
water−ethylene glycol solvents. Their three-dimensional frameworks consist of alternating ZnO46- tetrahedra and
HPO32- trigonal pyramids with an overall framework composition of [Zn3(HPO3)4]2-. The topology was analyzed by
converting these zincophosphites from their (3,4)-connected network into a four-connected framework. The symmetry
and charge density of three different structure-directing agents dictate the symmetry and framework density of
resulting inorganic frameworks. These zincophosphites are structural analogues of a known hydrogen phosphate,
suggesting that the bonding difference between −P−H and −P−OH plays an insignificant role in the formation of
phosphite and hydrogen phosphate open frameworks.