Hydrothermal synthesis and structures of two zero-dimensional zinc phosphate polymorphs

Two polymorphs of zero-dimensional zinc phosphate with the formula, 0∞[Zn(2,2′-bipy)(H2PO4)2], have been synthesized employing hydrothermal technique and their structure determined by single crystal X-ray diffraction. Both the structures consists of ZnO3N2 distorted trigonal-bipyramidal and PO2(OH)2 tetrahedral units linked through their vertices giving rise to a zero-dimensional molecular zinc phosphate. The structures are stabilized by extensive hydrogen bond interactions between zero-dimensional monomers. The structures display subtle differences in their packing created by hydrogen bond interactions. Crystal data: polymorph I, triclinic, space group P1¯ (No. 2), a=7.5446(15)Å, b=10.450(2)Å, c=10.750(2)Å, α=67.32(3)°, β=81.67(3)°, γ=69.29(3)°, V=731.4(3)Å3, Z=2; polymorph II, triclinic, space group P1¯ (No. 2), a=8.664(1)Å, b=8.849(2)Å, c=10.113(2)Å, α=97.37(2)°, β=100.54(2)°, γ=100.98(2)°, V=737.5(3)Å3, Z=2.