Related Experiment Video
Updated: Jun 24, 2026
13:21
Preparation, Purification, and Characterization of Lanthanide Complexes for Use as Contrast Agents for Magnetic Resonance Imaging
Published on: July 21, 2011
A purely lanthanide-based complex exhibiting ferromagnetic coupling and slow magnetic relaxation behavior
Zhi Chen1, Bin Zhao, Peng Cheng
1Department of Chemistry, Nankai University, Tianjin 300071, People's Republic of China.
Inorganic Chemistry
|March 20, 2009
Summary
Two new lanthanide-organic frameworks exhibit ferromagnetic coupling. Framework 2 shows rare slow magnetic relaxation, indicating potential for advanced magnetic materials.
Area of Science:
- Materials Science
- Inorganic Chemistry
- Magnetism
Background:
- Lanthanide-organic frameworks (LOFs) are crystalline materials with diverse applications.
- Investigating magnetic properties of LOFs is crucial for developing new magnetic materials.
- Thiophene-2,5-dicarboxylic acid (TDA) is a versatile ligand for constructing metal-organic frameworks.
Purpose of the Study:
- To synthesize and characterize two novel lanthanide-organic frameworks using TDA.
- To investigate the magnetic properties, including magnetic coupling and relaxation dynamics, of these frameworks.
- To explore the coexistence of ferromagnetic coupling and slow magnetic relaxation in 3D lanthanide-based frameworks.
Main Methods:
- Single-crystal X-ray diffraction for structural determination.
- Magnetic susceptibility measurements to analyze magnetic interactions.
- AC susceptibility measurements to study magnetic relaxation dynamics.
Main Results:
- Two 3D lanthanide-organic frameworks, {Ln(TDA)(1.5)(H2O)2}n (Ln = Gd (1), Dy (2)), were successfully synthesized.
- Ferromagnetic coupling was observed between adjacent lanthanide ions in both frameworks (1 and 2).
- Framework 2 exhibited slow magnetic relaxation behavior, a rare phenomenon in 3D lanthanide frameworks, with specific relaxation parameters (tau(0) = 2.4 x 10(-8) s, DeltaE/kB = 44.2 K).
Conclusions:
- The synthesized LOFs demonstrate the utility of TDA as a ligand for creating functional magnetic materials.
- The coexistence of ferromagnetic coupling and slow magnetic relaxation in framework 2 is a significant finding for the design of single-molecule magnets.
- These results contribute to the understanding of structure-property relationships in lanthanide-based magnetic materials.
More Related Videos
09:38Fabrication Procedures and Birefringence Measurements for Designing Magnetically Responsive Lanthanide Ion Chelating Phospholipid Assemblies
Published on: January 3, 2018
10:45Stable Aqueous Suspensions of Manganese Ferrite Clusters with Tunable Nanoscale Dimension and Composition
Published on: February 5, 2022
Related Concept Videos
03:02Colors and Magnetism
Color in Coordination Complexes
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 eye.
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 eye.
01:31Ferromagnetism
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
02:42Valence Bond Theory
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
01:28Atomic Nuclei: Types of Nuclear Relaxation
Nuclear relaxation restores the equilibrium population imbalance and can occur via spin–lattice or spin–spin mechanisms, which are first-order exponential decay processes.
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers energy to a nearby...
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers energy to a nearby...
01:23Atomic Nuclei: Nuclear Relaxation Processes
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis. This...
01:26Diamagnetism
Materials consisting of paired electrons have zero net magnetic moments. However, when these materials are placed under an external magnetic field, the moments opposite to the field are induced. Such materials are called diamagnets. Diamagnetism is the response of the diamagnets when placed in an external magnetic field.
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets.
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets.