Related Experiment Video
Updated: Jan 9, 2026

Hyperspectral Imaging as a Tool to Study Optical Anisotropy in Lanthanide-Based Molecular Single Crystals
Published on: April 14, 2020
Triply halogen-bridged erbium compounds with hard single-molecule magnet behavior
Qi-Wei Chen1,2, You-Song Ding2, Jia-Qi Huang2
1School of Chemical Engineering, Guizhou University of Engineering Science, Bijie, Qixingguan District, China.
None:
Single-molecule magnets (SMMs) show promise for high-density data storage due to molecular-level magnetic hysteresis, but low-temperature quantum tunneling of magnetization (QTM) limits their blocking temperatures (TB), making QTM suppression critical. Herein, we report two dinuclear Er-cyclooctatetraenyl compounds: [K(18-C-6)(THF)][(COT1,4TMS2)Er(μ-Cl)₃Er(COT1,4TMS2)] (1) and [K(18-C-6)(THF)₂][(COT1,3TMS2)Er(μ-Br)₃Er(COT1,3TMS2)] (2) (COT1,4TMS2 and COT1,3TMS2 donate 1,4- and 1,3-bis(trimethylsilyl)-substituted cyclooctatetraenyl ligands, respectively; 18-C-6 = 18-Crown-6 ether). In both compounds, the two Er(III) ions are triply bridged by Cl- (1) or Br- (2). Ab initio calculations confirm strong axial anisotropy and ferromagnetic axial dipolar interactions from "head-to-tail" magnetic easy axes. Such axial dipolar interactions lead to the QTM being effectively suppressed by minimizing transverse dipolar fields, yielding hard magnetic behavior with open magnetic hysteresis loops up to 10 K and coercive fields of 6.25 kOe (1) and 4.75 kOe (2) at 2 K. These results demonstrate tunable halide-bridged dinuclear architectures for hard-magnetic SMMs via a non-radical approach.
Related Concept Videos
Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
Valence Bond Theory
Hybridization of Atomic Orbitals I
Ferromagnetism
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...
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...

