Synthesis, characterization and magnetic property of a new 3D iron phosphite: |C 4N 3H 14|[Fe 3(HPO 3) 4F 2(H 2O) 2] with intersecting channels

Abstract

A new open-framework iron (III) phosphite |C 4N 3H 14|[Fe 3(HPO 3) 4F 2(H 2O) 2] has been solvothermally synthesized by using diethylenetriamine (DETA) as the structure-directing agent. Single-crystal X-ray diffraction analysis reveals that the compound crystallizes in the monoclinic space group C2/ c having unit cell parameters a=12.877(3) Å, b=12.170(2) Å, c=12.159(2) Å, β=93.99(3)°, V=1900.9(7) Å 3, and Z=4 with R 1=0.0447, w R 2=0.0958. The complex structure consists of HPO 3 pseudo-tetrahedra and {Fe 3O 14F 2} trimer building units. The assembly of these building units generates 3D inorganic framework with intersecting 6-, 8-, and 10-ring channels. The DETA cations are located in the 10-ring channels linked by hydrogen bonds. The Mössbauer spectrum shows that there exhibit two crystallographically independent iron (III) atoms. And the magnetic investigation shows the presence of antiferromagnetic interactions. Further characterization of the title compound was performed using X-ray powder diffraction (XRD), infrared (IR) spectra, thermal gravimetric analyses (TGA), inductively coupled plasma (ICP) and elemental analyses.