Related Experiment Video
Updated: Mar 31, 2026
Author Spotlight: Experimental Approaches for the Synthesis of Low-Valent Metal-Organic Frameworks from Multitopic Phosphine Linkers
Published on: May 12, 2023
Constraining and Tuning the Coordination Geometry of a Lanthanide Ion in Metal-Organic Frameworks: Approach toward a
Ke Liu1, Huanhuan Li1, Xuejing Zhang1
1Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE), Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University , Tianjin 300071, P. R. China.
Abstract:
It is available to constrain and tune the coordination geometries around lanthanide ions in metal-organic frameworks (MOFs) for the study of single-molecule-magnet (SMM) behavior. A series of Dy(III)-MOFs are synthesized via a solvothermal method by using furan-2,5-dicarboxylic acid (H2FDA) as the ligand. {[Dy2(FDA)3(DMF)2]·1.5DMF}n (1) and [Dy2(FDA)3(DMF)2(CH3OH)]n (2) show similar three-dimensional structures, but the coordination geometries around the dysprosium(III) ions in 1 and 2 exhibit different deviations from ideal square antiprism (D4d symmetry) because of the coordinated solvent molecules. Slow relaxation of the magnetization can be observed for both complexes, indicative of SMM behavior. The effective energy barriers for 1 and 2 can be obtained from alternating-current susceptibility measurements by applying an external 2000 Oe direct-current field. MOF 2 possesses a less distorted D4d coordination sphere and gives a higher effective energy barrier (Ueff) than that of MOF 1. Their diamagnetic Y(III)-diluted samples 1@Y and 2@Y exhibit similar relationships between the geometries and Ueff values, demonstrating that the magnetization relaxation is mainly from the symmetry-related single-ion behavior.
Related Concept Videos
02:42Valence Bond Theory
02:58Crystal 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...
02:57Coordination Number and Geometry
02:51Metal-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...
02:46Crystal 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,...
03:02Colors 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...