Fe2(AsO4)F: A new three-dimensional condensed fluoro-arsenate iron(II) compound with antiferromagnetic interactions

摘要: Fe{sub 2}(AsO{sub 4})F has been synthesized under mild hydrothermal conditions in the form of single crystals. The compound crystallizes C2/c monoclinic space group with unit cell parameters a=13.214(1), b=6.623(1), c=10.045(1)A and {beta}=116.90(2) deg. Z=8. crystal structure consists a three-dimensional framework constructed by two kinds chains, A B, 50% population. In environments for iron(II) cations show penta- hexa-coordination. chains establish an angle approximately 120 between them. disordered fluoride anions these given rise to [Fe(1)O{sub 4}F(1){sub 0.5}(F(2){sub 0.5}){sub 2}] [Fe(2)O{sub 4}(F(1){sub 2}F(2){sub 0.5}] edge-shared polyhedra which have occupancy factors over distinct crystallographic sites. IR spectrum shows characteristic bands (AsO{sub 4}){sup 3-} groups. From diffuse reflectance D{sub q} parameter 650cm{sup -1} calculated Fe(II) d{sup 6} high spin cation. Mossbauer paramagnetic state doublet that fitted, according existence crystallographically independent iron environments, Lorentzian doublets. Magnetic measurements performed room temperature 5K exhibit maximum at 22.6K, antiferromagneticmore » interactions estimated 'J'-exchange -1.2K.« less