Structure of the new iron(II) oxalate potassium salt K2Fe[(C2O4)2(H2O)2]·0.18H2O

The discovery of a new FeII oxalate framework of composition K2Fe[(C2O4)2(H2O)2]·0.18H2O is reported. Its crystal structure was solved by means of single crystal and powder X‐ray diffraction. The new organic–inorganic hybrid compound crystallizes in the orthorhombic space group Pca21 with unit‐cell parameters: a = 12.0351 (4) Å, b = 15.1265 (5) Å, c = 10.5562 (4) Å. This crystal structure, containing eight chemical formula, consists of a succession of FeO4(H2O)2 octahedra and K+ cations growing along b direction. Magnetization measurements indicate that the title compound is paramagnetic over the investigated temperature range (2–300 K). Both magnetization and 57Fe Mössbauer data indicate that Fe2+ is in a high‐spin state. The crystal structure of a new FeII‐based metal organic framework of composition K2Fe[(C2O4)2(H2O)2]·0.18H2O is resolved using single crystal and powder X‐ray diffraction.