Related Experiment Video
Updated: Jul 26, 2025

Molten-Salt Synthesis of Complex Metal Oxide Nanoparticles
Published on: October 27, 2018
Structure of the new iron(II) oxalate potassium salt K2Fe[(C2O4)2(H2O)2]·0.18H2O
Sara Amanchar1, Thierry Schweitzer1, Thomas Mazet1
1Université de Lorraine, CNRS, IJL, F-54000 Nancy, France.
Abstract:
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.
Related Concept Videos
Formation of Complex Ions
Ionic Crystal Structures
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Ions as Acids and Bases
Salts are ionic compounds composed of cations and anions, either of which may be capable of undergoing an acid or base ionization reaction with water. Aqueous salt solutions, therefore, may be acidic, basic, or neutral, depending on the relative acid-base strengths of the salt’s constituent ions. For example, dissolving the ammonium chloride in water results in its dissociation, as described by the equation:
Alkali Metals
Table 1: Properties of the alkali metals
Ionic Compounds: Formulas and Nomenclature
Lewis Structures of Molecular Compounds and Polyatomic Ions

