title: Synthesis, structural characterisation and magnetic studies of polymetallic iron phosphonate cages.
abstract: Four new polymetallic iron(III) phosphonate cages have been made and structurally characterised. These are an octanuclear cage [Fe(8)O(3)(OH)(2)(O(2)C(t)Bu)(11)(PhCH(2)PO(3))(3)(py)(3)], a decanuclear cage [Fe(10)O(2)(OH)(8)(O(2)C(t)Bu)(10)(PhCH(2)PO(3))(4)(pip)(2)], a heterometallic cage [Fe(6)Li(5)(mu(3)-O)(2)((t)BuPO(3))(6)(O(2)C(t)Bu)(8)(MeOH)(2)(Py)(4)] and a tridecanuclear cage [Et(3)NH](2)[Fe(13)(mu(3)-O)(3)(mu(2)-OH)(7)((t)BuPO(3))(7)(Me(3)CCO(2))(14)(H(2)O)] (pip = piperidine, py = pyridine). Magnetic studies of the first three compounds show anti-ferromagnetic exchange between the iron(III) centers leading to diamagnetic ground states for the homometallic cages. For the heterometallic cage, the six Fe(III) centers are arranged in two triangles, and each triangle has an S = 1/2 spin ground state.
authors.affiliation: Department of Chemistry, School of Chemistry, The University of Manchester, Oxford Road, Manchester, UK M13 9PL.
authors.forename: Sumit
authors.initials: S
authors.lastname: Khanra
authors.forename: Madeleine
authors.initials: M
authors.lastname: Helliwell
authors.forename: Floriana
authors.initials: F
authors.lastname: Tuna
authors.forename: Eric J L
authors.initials: EJ
authors.lastname: McInnes
authors.forename: Richard E P
authors.initials: RE
authors.lastname: Winpenny
mesh_terms: D018360:Crystallography, X-Ray; D005290:Ferric Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D008280:Magnetics; D008958:Models, Molecular; D015394:Molecular Structure; D063065:Organophosphonates / Q000737:chemistry*
chemical_list: D005290:Ferric Compounds; D063065:Organophosphonates