Synthesis, structure and magnetic properties of a new one-dimensional iron phosphite, [FeIII(1,10-phenanthroline)(HPO3)(H 2PO3)]

A new iron phosphite, [FeIII(1,10-phen)(HPO3)(H 2PO3)], I, has been synthesized hydrothermally from a mixture containing iron powder, phosphorous acid, 1,10-phenanthroline and water at 125°C for 7 days. The structure consists of an edge-shared four-membered rings formed by the connectivity between FeO4N2 octahedra and pseudo pyramidal HPO3 units, connected through their edges forming a one-dimensional structure. The 1,10-phenanthroline molecules and H2PO3 pseudo-tetrahedral units bound with the Fe centre project into the inter-chain spaces. Magnetic investigations reveal that the iron is present in +3 oxidation state, and at low-temperature the sample orders antiferromagnetically with TN = â?¼ 16 K. Crystal data: I, monoclinic, space group = P2(1)/m (no. 11), a = 10.180(3), b = 6.424(1), c = 11.6668(5) Ã?, β = 115.59(1)° , V = 668.2(4) Ã?3, Z = 4, Ï?calc = 1.880 g/cm3, μ (Mo Kα) = 3.456 mm-1, R1 = 0.0313 and wR2 = 0.0725 data [I < 2Ï?(I)].