Related Experiment Video
Updated: Jun 26, 2026

Molten-Salt Synthesis of Complex Metal Oxide Nanoparticles
Published on: October 27, 2018
22-Isopolytungstate fragment [H2W22O74]14- coordinated to lanthanide ions
Amal H Ismail1, Michael H Dickman, Ulrich Kortz
1School of Engineering and Science, Jacobs University, P.O. Box 750 561, 28725 Bremen, Germany.
Abstract:
The novel polyanions [Ln(2)(H(2)O)(10)W(22)O(71)(OH)(2)](8-) (Ln = La (1), Ce (2), Tb (3), Dy (4), Ho (5), Er (6), Tm (7), Yb (8), Lu (9), Y (10)) have been synthesized by reaction of WO(4)(2-) and lanthanide ions in acidic aqueous medium. The low symmetry (C(i)) polyanion family [Ln(2)(H(2)O)(10)W(22)O(71)(OH)(2)](8-) consists of the isopolyanion [H(2)W(22)O(74)](14-) and two {Ln(H(2)O)(5)}(3+) supporting units. The [H(2)W(22)O(74)](14-) cluster, which consists of two undecatungstate {W(11)} fragments, acts as a tridentate ligand to two Ln(3+) ions. Polyanions 1-10 are isostructural, and the coordination number of the lanthanide ions correlates with their sizes. All compounds have been fully characterized in the solid state by Fourier transform infrared spectroscopy, single-crystal X-ray diffraction, thermogravimetric analysis, and elemental analysis. Single-crystal X-ray diffraction analyses show that 1-10 crystallize as sodium salts in the triclinic space group P1.
More Related Videos
Related Concept Videos
Valence Bond Theory
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...
Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Metal-Ligand Bonds
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
Coordination Number and Geometry
Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...

