Crystal structure of hydrazine iron(III) phosphate, the first transition metal phosphate containing hydrazine

The title compound, poly[(μ(2)-hydrazine)(μ(4)-phosphato)iron(III)], [Fe(PO(4))(N(2)H(4))](n), was prepared under hydro­thermal conditions. Its asymmetric unit contains one Fe(III) atom located on an inversion centre, one P atom located on a twofold rotation axis, and two O, one N and two H atoms located on general positions. The Fe(III) atom is bound to four O atoms of symmetry-related PO(4) tetra­hedra and to two N atoms of two symmetry-related hydrazine ligands, resulting in a slightly distorted FeO(4)N(2) octa­hedron. The crystal structure consists of a three-dimensional hydrazine/iron phoshate framework whereby each PO(4) tetra­hedron bridges four Fe(III) atoms and each hydrazine ligand bridges two Fe(III) atoms. The H atoms of the hydrazine ligands are also involved in moderate N—H⋯O hydrogen bonding with phosphate O atoms. The crystal structure is isotypic with the sulfates [Co(SO(4))(N(2)H(4))] and [Mn(SO(4))(N(2)H(4))].