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Preparation, Purification, and Characterization of Lanthanide Complexes for Use as Contrast Agents for Magnetic Resonance Imaging
Published on: July 21, 2011
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Atomically Precise Lanthanide-Iron-Oxo Clusters Featuring the ϵ-Keggin Ion.
Xiu-Ying Zheng1,2, Ming-Hao Du1, Mehran Amiri3
1Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|November 13, 2019
Summary
Researchers synthesized novel lanthanide-iron oxo clusters, providing molecular models for iron oxide phases like ferrihydrite and magnetite. These stable, tunable clusters offer insights into self-assembly and magnetic properties.
Area of Science:
- Inorganic Chemistry
- Materials Science
- Nanotechnology
Background:
- Atomically precise molecular metal-oxo clusters are crucial for understanding metal oxide surfaces and self-assembly.
- Synthesizing and isolating these molecular clusters presents significant challenges.
- The {Fe13} metal-oxo cluster motif is fundamental to iron oxyhydroxide phases like ferrihydrite and magnetite.
Purpose of the Study:
- To report the synthesis and characterization of novel lanthanide-iron oxo clusters.
- To utilize the isolated ϵ-{Fe13} Keggin isomer as a model for studying ferrihydrite and magnetite formation.
- To explore the potential for tuning magnetic exchange properties through compositional modification.
Main Methods:
- Synthesis of four isostructural lanthanide-iron-oxo clusters.
- Characterization using X-ray crystallography, Small-angle X-ray scattering (SAXS), and high-resolution electrospray ionization mass spectrometry (HRESI-MS).
- Investigating cluster stability in aqueous and organic solvents.
Main Results:
- Successful synthesis of four Ln-Fe oxo clusters featuring the ϵ-{Fe13} Keggin core.
- The metal layer surrounding the core mimics the magnetite lattice, with Fe and Ln occupying similar positions.
- Clusters demonstrate stability in both water and organic solvents upon dissolution.
- The compounds are formulated as [Y12Fe33(TEOA)12(Hyp)6(μ3-OH)20(μ4-O)28(H2O)12](ClO4)23·50H2O, [Gd12Fe33(TEOA)12(Hyp)6(μ3-OH)20(μ4-O)32(H2O)12](ClO4)15·50H2O, and Ln16Fe29(TEOA)12(Hyp)6(μ3-OH)24(μ4-O)28(H2O)16](ClO4)16(NO3)3·nH2O (Ln=Y, Gd).
Conclusions:
- The synthesized molecular clusters serve as valuable models for iron oxide phases.
- These clusters facilitate the study of ferrihydrite and magnetite formation from a pre-formed building unit.
- The ability to tune composition allows for optimization of magnetic exchange interactions.
- The stability and solubility of these clusters pave the way for constructing magnetic arrays and investigating mineral assembly.
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