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

The title compound, poly[(mu(2)-hydrazine)(mu(4)-phosphato) iron(III)], [Fe(PO4)-(N2H4)](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 PO4 tetrahedra and to two N atoms of two symmetry-related hydrazine ligands, resulting in a slightly distorted FeO4N2 octahedron. The crystal structure consists of a three-dimensional hydrazine/iron phoshate framework whereby each PO4 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 center dot center dot center dot O hydrogen bonding with phosphate O atoms. The crystal structure is isotypic with the sulfates [Co(SO4)(N2H4)] and [Mn(SO4)(N2H4)].