Related Experiment Video
Updated: Sep 29, 2026

Molten-Salt Synthesis of Complex Metal Oxide Nanoparticles
Published on: October 27, 2018
Out-of-center distortions in d(0) transition metal oxide fluoride anions
Margaret E Welk1, Alexander J Norquist, Frederick P Arnold
1Department of Chemistry, Northwestern University, Evanston, IL 60208-3113, USA.
Abstract:
Electronic effects and the bond network are the two factors that cause out-of-center distortions in octahedral d(0) transition metal oxide fluoride anions. Overlap between filled oxide p orbitals and vacant cation d orbitals results in strong, short metal-oxide bonds causing the metal ion to distort toward the oxide ligand. This primary, electronic distortion is not dependent on the extended structure. Smaller, secondary distortions of the anionic octahedra are caused by interactions with the bond network. [HNC(6)H(6)OH](2)[Cu(NC(5)H(5))(4)(NbOF(5))(2)], prepared with 5-hydroxy-2-methylpyridine that provides two coordination contact sites to the anion when protonated, exhibits distortions in the anion reflecting both factors. Crystal data for [HNC(6)H(6)OH](2)[Cu(NC(5)H(5))(4)(NbOF(5))(2)]: monoclinic, space group C2/c (No. 15), with a = 10.9427(8) A, b = 16.204(1) A, c = 21.396(2) A, beta = 93.263(1) degrees, and Z = 4. Conditions for detection of both distortion types are discussed with five additional examples.
More Related Videos
Related Concept Videos
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...
Imperfections in Crystal Structure: Non-Stoichiometric Defects
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...
Valence Bond Theory
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,...
Imperfections in Crystal Structure: Stoichiometric Point Defects

