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Amide Coupling Reaction for the Synthesis of Bispyridine-based Ligands and Their Complexation to Platinum as Dinuclear Anticancer Agents
Published on: May 28, 2014
14.1K
Di-Pyridine-Containing Macrocyclic Triamide Fe(II) and Ni(II) Complexes as ParaCEST Agents
Rabindra N Pradhan1, Pietro Irrera2, Feriel Romdhane3
1School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Bhubaneswar752050, India.
Inorganic Chemistry
|October 7, 2022
Summary
New iron and nickel complexes with the DETA ligand show promise as paramagnetic chemical exchange saturation transfer (paraCEST) contrast agents. The iron complex exhibits superior CEST contrast efficiency at body temperature, suggesting potential for MRI applications.
Area of Science:
- Coordination Chemistry
- Supramolecular Chemistry
- Magnetic Resonance Imaging (MRI) Contrast Agents
Background:
- Development of novel paramagnetic contrast agents for enhanced MRI sensitivity.
- Exploration of macrocyclic ligands for stable metal complex formation.
- Chemical Exchange Saturation Transfer (CEST) as a sensitive MRI technique.
Purpose of the Study:
- To synthesize and characterize novel Fe(II) and Ni(II) complexes with the DETA macrocyclic ligand.
- To evaluate the potential of these complexes as paramagnetic CEST (paraCEST) contrast agents.
- To assess the structural, electronic, and stability properties of the synthesized metal complexes.
Main Methods:
- Synthesis and structural characterization of Fe(II) and Ni(II) complexes using X-ray crystallography.
- Evaluation of paraCEST properties through NMR spectroscopy, including CEST peak analysis.
- Potentiometric titrations to determine protonation and stability constants of metal complexes.
Main Results:
- Structural elucidation revealed distorted pentagonal bipyramidal geometry for [Fe(DETA)]2+ and distorted octahedral for [Ni(DETA)]2+.
- [Fe(DETA)]2+ demonstrated well-resolved proton resonances and significant CEST contrast efficiency with peaks at 84 ppm and 28 ppm.
- [Ni(DETA)]2+ exhibited broad resonances and a single CEST peak at 78 ppm; both complexes showed good stability in acidic conditions.
Conclusions:
- The synthesized Fe(II) and Ni(II) DETA complexes are structurally characterized and stable.
- The Fe(II) complex shows promising paraCEST properties, particularly its high CEST contrast efficiency at body temperature.
- These findings highlight the potential of Fe(II)-DETA complexes as novel MRI contrast agents.
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