A hybrid open-framework structure: synthesis and structure of an iron phosphate oxalate, [C10N4H28][Fe2(HPO4)3(C2O4)]2

Abstract

A new inorganic–organic hybrid structure has been synthesized hydrothermally in the iron phosphate oxalate family using 1,4-bis(3-aminopropyl)piperazine as the structure-directing agent. Crystal data for I, [C₁₀N₄H₂₈][Fe₂(HPO₄)₃(C₂O₄)]₂: M = 589.8, monoclinic, space group = P2₁/n (no. 14), a = 10.829(1), b = 12.747(1), c = 12.397(1) Å, β = 95.1(1)°, V = 1704.4(3) Å3, Z = 4, R = 0.036 and R_w = 0.083 [1860 observed reflections with I > 2σ(I)]. The structure comprises a network of FeO₆ octahedra and PO₄ tetrahedra forming inorganic layers which are bridged by the oxalate units forming 8-membered channels in which the amine molecule resides. Magnetic susceptibility studies indicate an antiferromagnetic behavior with T_N = ≈40 K, the highest known in an open-framework material.