(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 [Zn-3(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.