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Updated: Oct 10, 2025
11:22
Investigations on the GaIII Complex of EOB-DTPA and Its 68Ga Radiolabeled Analogue
Published on: August 17, 2016
10.1K
Pair distribution function and 71Ga NMR study of aqueous Ga3+ complexes
Ida Gjerlevsen Nielsen1, Sanna Sommer1, Ann-Christin Dippel2
1Center for Materials Crystallography, Department of Chemistry, Interdisciplinary Nanoscience Center (iNANO), Aarhus University 8000 Aarhus C Denmark bo@chem.au.dk.
Chemical Science
|December 9, 2021
Summary
This study reveals the atomic structures of gallium(III) ions in water across various pH levels. It identifies different gallium species, including novel polyoxogallates, crucial for semiconductor and medical uses.
Area of Science:
- Inorganic Chemistry
- Solution Chemistry
- Materials Science
Background:
- Understanding metal ion aqueous coordination chemistry is fundamental.
- Accurate structural data for metal ion solution species is often limited.
- Gallium(III) ion speciation is critical for semiconductor fabrication and medical applications.
Purpose of the Study:
- To determine the atomic structures of gallium(III) ion complexes in aqueous solutions.
- To investigate the influence of pH, counter anions, and concentration on gallium speciation.
- To provide a comprehensive structural exploration of Ga³⁺ aqueous chemistry at atomic resolution.
Main Methods:
- X-ray pair distribution function (XPDF) analysis.
- 71Ga Nuclear Magnetic Resonance (NMR) spectroscopy.
- Direct determination of atomic structures in solution.
Main Results:
- At low pH (<2), Ga³⁺ exists as monomers or dimers with octahedral coordination and ordered solvent.
- At pH ≈ 2-3, novel polyoxogallate structures (Ga₃₀ or Ga₃₂) were identified, differing from proposed Keggin structures.
- At neutral to higher pH, nanosized GaOOH particles form; at pH > 12, tetrahedral Ga³⁺ with ordered solvent is observed.
- Concentration and counter anion variations showed minimal structural impact.
Conclusions:
- This research provides the first atomic-resolution structural insights into aqueous Ga³⁺ chemistry.
- The identified species and structural transitions are vital for understanding gallium's behavior in solution.
- Findings have significant implications for optimizing semiconductor fabrication processes and advancing medical applications of gallium.
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