title: Iron arsenate frameworks.
abstract: Six new iron arsenate framework structures, Fe(2)As(2)O(7) x 2H(2)O, [Fe(6)As(8)O(32)H(4)](2-)(1,4-butanediamininium(2+)) x 2H(2)O, [Fe(4)As(6)O(22)H(2)](2-)(piperazinium(2+)), [Fe(5)As(5)O(24)H(4)](2-)(piperazinium(2+)) x 2H(2)O, [Fe(6)As(7)O(31)H(5)](2-)(dabco(2+)) and LiFeAsO(4)OH have been synthesised under hydrothermal conditions. Incorporation of the amine cation templates leads to more open framework geometries and, in contrast to iron phosphates which have topologies based on PO(4) tetrahedra, the iron arsenate structures typically contain protonated As(O,OH)(4) units. The magnetic properties of the iron arsenates studied show Curie-Weiss behaviours with maxima in the chi(T) vs.T plots in the range 10-50 K.
authors.affiliation: School of Chemistry, University of Southampton, Southampton, UKSO17 1BJ.
authors.forename: Seth B
authors.initials: SB
authors.lastname: Wiggin
authors.forename: Robert W
authors.initials: RW
authors.lastname: Hughes
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Price
authors.forename: Mark T
authors.initials: MT
authors.lastname: Weller