Solution-mediated synthesis of a three-dimensional zinc phosphate in the presence of a monoamine

A new open-framework zinc phosphate of the formula [C2H5NH3]2[Zn2(HPO4)3], I, has been synthesized at 60 °C in a THF–water medium in the presence of ethylamine. The structure consists of a network of strictly alternating ZnO4 and PO4 tetrahedra forming 4- and 8-membered rings, which connect to form intersecting elliptical channels bound by 12- and 8-T atoms (T = Zn, P) along the c and b axes, respectively. The amine molecule sits in the channel bound by 12-T atoms and the –OH group of the HPO4 unit protrudes into the 8-membered channel. An interesting feature of I is that it has a very low framework density. Crystal data: [C2H5NH3]2[Zn2(HPO4)3], monoclinic, C2/c (no. 15), a = 17.351(4), b = 9.507(5), c = 9.806(5) Å, β = 102.68(2)°, V = 1578.3(1) Å3, Z = 4.