NaZnPO₄·H₂O, an Open-Framework Sodium Zincophosphate with a New Chiral Tetrahedral Framework Topology

Two approaches to the synthesis and structure determination of NaZnPO 4 ·H 2 O, a new open-framework, chiral, hydrated sodium zincophosphate phase, are reported. The ordered, alternating, vertex-sharing ZnO 4 and PO 4 groups in NaZnPO 4 ·H 2 O form a new framework topology, which includes novel 4-ring “squares” and edge-sharing helixes of 4-rings. The disordered extra-framework species (Na +, H 2 O) are located in pear-shaped cavities (12-ring diameter), interconnected through 8-rings and 6-rings. Crystal data: NaZnPO 4 ·H 2 O ( I ), M r = 201.36, hexagonal, space group P 6 1 22 (No. 178), a = 10.4797(8) Å, c = 15.089(2) Å, V = 1435 Å 3, Z = 12, R = 5.99%, R w = 5.29% (709 observed reflections with I > 3σ( I ). NaZnPO 4 ·H 2 O ( II ), M r = 201.36, hexagonal, space group P 6 5 22 (No. 179), a = 10.412(2) Å, c = 15.184(2) Å, V = 1426 Å 3, Z = 12, R = 6.90%, R w = 8.10% (687 observed reflections with I > 4σ( I ).