APA2[Zn3(HPO4)4(H2O)2], a Layered Zincophosphate Featuring Template-to-Framework N-H•••O and "Synergic" Framework-to-Template O-H•••N Hydrogen Bonds and C-H•••O Interactions (APA=2-Amino-1-phenyleneammonium, C6H9N2+)

The crystal structure of APA(2)[Zn-3(HPO4)(4)(H2O)(2)] (APA = 2-amino-1-phenylene-ammonium, C6H9N2+) (1), as prepared by a predominantly non-aqueous synthesis, is described and compared to related compounds. 1 is built up from an alternating array of ZnO4 and HPO4 tetrahedra sharing vertices as Zn-O-P bonds to generate infinite anionic sheets. Within these sheets, polyhedral 4-, 6-and 8-rings are apparent. The negative charge of the inorganic layer is balanced by singly-protonated APA template cations and water molecules are also present. The components are linked by N-t-H center dot center dot center dot O-f, O-f-H center dot center dot center dot O-w, O-w-H center dot center dot center dot O-f and O-f-H center dot center dot center dot N-t (t = template, f = framework, w = water) hydrogen bonds: the last of these represents an unusual framework-to-template interaction. Weak Ct-HLOf links may also play a role in consolidating the structure. Crystal data: 1 (C12H26N4O18P4Zn3), M-r = 834.36, monoclinic, C2/c (No. 15), Z = 4, a = 20.194 (8) angstrom, b = 8.682 (3) angstrom, c = 15.123 (6) angstrom, beta = 91.510 (11)degrees, V = 2650.5 (17) angstrom(3), R(F) = 0.048, wR(F-2) = 0.112.