Related Experiment Video
Updated: Feb 26, 2026
13:21
Preparation, Purification, and Characterization of Lanthanide Complexes for Use as Contrast Agents for Magnetic Resonance Imaging
Published on: July 21, 2011
15.4K
Structural Features of Europium(II)-Containing Cryptates That Influence Relaxivity
Chamika U Lenora1, Fabio Carniato2, Yimin Shen3
1Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI, 48202, USA.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|July 15, 2017
Summary
Researchers investigated Europium(II)-containing complexes for magnetic resonance imaging contrast agents. Studies focused on how molecular changes and field strength affect relaxivity, guiding future contrast agent development.
Area of Science:
- Materials Science
- Biomedical Imaging
- Inorganic Chemistry
Background:
- Europium(II) complexes show potential as contrast agents for magnetic resonance imaging (MRI).
- Understanding relaxivity is crucial for optimizing MRI contrast agent performance.
- Molecular parameters and field strength significantly influence relaxivity.
Purpose of the Study:
- To investigate the properties of Europium(II)-containing complexes for MRI applications.
- To determine the impact of molecular variations and magnetic field strength on relaxivity.
- To characterize the water coordination and dynamic properties of these complexes.
Main Methods:
- Synthesis and characterization of Europium(II)-containing cryptates and their adducts.
- Solid- and solution-state characterization to confirm inner-sphere water molecules.
- Variable-temperature 17O NMR, nuclear magnetic relaxation dispersion (NMRD), and electron paramagnetic resonance (EPR) spectroscopy.
Main Results:
- Demonstrated the presence of inner-sphere water molecules in Eu(II) complexes.
- Quantified relaxivity, water-exchange rates, rotational correlation times, and electronic relaxation times.
- Established relationships between molecular parameters, field strength, and relaxivity.
Conclusions:
- The study provides critical data for designing novel Europium(II)-based MRI contrast agents.
- Understanding relaxivity mechanisms is key to enhancing MRI sensitivity and resolution.
- These findings pave the way for more effective diagnostic imaging agents.
More Related Videos
07:24Hyperspectral Imaging as a Tool to Study Optical Anisotropy in Lanthanide-Based Molecular Single Crystals
Published on: April 14, 2020
18.7K
07:24Quantitative Atomic-Site Analysis of Functional Dopants/Point Defects in Crystalline Materials by Electron-Channeling-Enhanced Microanalysis
Published on: May 10, 2021
6.9K
Related Concept Videos
02:58Crystal Field Theory - Octahedral Complexes
31.2K
Crystal Field Theory
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...
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...
31.2K
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
49.0K
Tetrahedral 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,...
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,...
49.0K
01:28Atomic Nuclei: Types of Nuclear Relaxation
1.1K
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...
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...
1.1K
03:02Colors and Magnetism
14.3K
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...
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...
14.3K
02:52Stereoisomerism
14.2K
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
14.2K
02:42Valence Bond Theory
11.4K
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...
11.4K