Hydrothermal synthesis, crystal structure, and spectroscopic and magnetic properties of a new organically templated mixed-anion fluoro-arsenate-phosphate iron(III) compound, (C6H14N2)[Fe-3(HAsO4)(1.33)(HPO4)(0.67)(ASO(4))(0.84)(PO4)(0.16)F-4]0.5( H2O)

作者：Bazan B; Mesa JL^*; Pizarro JL; Lezama L; Garitaonandia JS; Arriortua MI; Rojo T

来源：Solid State Sciences, 2003, 5(9): 1291-1301.

DOI：10.1016/S1293-2558(03)00144-4

• hydrothermal synthesis
• organically templated material
• crystal structure
• spectroscopic and magnetic properties

The new organically templated mixed-anion fluoro-arsenate-phosphate iron(III) compound, with formula (C6H14N2)[Fe-3(HAsO4)(1.33)-(HPO4)(0.67)(AsO4)(0.84)(PO4)(0.16)F-4]0.5(H2O), has been synthesized by using mild hydrothermal conditions under autogeneous pressure. The crystal structure has been solved from X-ray single crystal data. The unit-cell parameters are a = 18.267(1), b = 10.085(1), c = 20.436(2) Angstrom, beta = 105.97(1)degrees. Monoclinic, C2/c with Z = 8. The structure consists of a three-dimensional inorganic framework formed by [Fe-3(HAsO4)(1.33)(HPO4)(0.67)(AsO4)(0.84)(PO4)(0.16)F-4](2-) inorganic layers linked by hydrogen-arsenate/phosphate anions. There are three iron atoms crystallographically independent per unit-formula. The sheets are constructed from Fe(1)Fe(3)O6F4 and Fe(2)(2)O8F2 dimeric units with edge-sharing octahedra. The 1,4-diazabicyclooctane dications are located inside the cavities of the inorganic skeleton. The IR and Raman spectroscopies confirm the simultaneously existence of both the arsenate/hydrogenarsenate and phosphate/hydrogenphosphate anions. From the diffuse reflectance spectrum the Dq = 1080 and Racah parameters B = 1040 and C = 2620 cm(-1) for the d(5)-high spin iron(III) cation in octahedral geometry have been calculated. The Mossbauer spectrum at room temperature is characteristic of high spin iron(III) cations. The ESR spectra are isotropic with a g-value of 1.99(1), which remains unchanged with variation in temperature. Magnetic measurements indicate the presence of antiferromagnetic interactions with a maximum in the susceptibility at around 6.0 K.

• 出版日期2003-9