Study on Semi-Glycinecresol Red complexes with bivalent metal ions
T Yoshino1, S Murakami, K Arita
1Department of Chemical Technology, Faculty of Engineering, Yamaguchi University, Tokiwadai, Ube 755, Japan.
Talanta
|June 1, 1979
Summary
Semi-Glycinecresol Red (SGCR) forms complexes with bivalent metal ions. SGCR is a suitable indicator for copper, zinc, and lead ions in various pH conditions.
Area of Science:
- Analytical Chemistry
- Coordination Chemistry
Background:
- Semi-Glycinecresol Red (SGCR) is a ligand with potential applications in metal ion detection.
- Understanding its complexation behavior with bivalent metal ions is crucial for its use as an indicator.
Purpose of the Study:
- To investigate the complex formation equilibria between bivalent metal ions and SGCR.
- To determine the acid-base and metal-ligand stoichiometries, formation constants, and spectral properties of these complexes.
- To evaluate SGCR's suitability as a metal ion indicator.
Main Methods:
- Purification of SGCR using chromatography and cation-exchange.
- Potentiometric and spectrophotometric studies to determine complexation equilibria.
- Electron Spin Resonance (ESR) spectroscopy to analyze copper complexes.
Main Results:
- SGCR forms 1:1 and 1:2 (metal:ligand) complexes with bivalent metal ions in alkaline solutions.
- Protonated copper complexes (CuHSGCR and Cu(HSGCR)(2-)(2)) were identified in weakly acidic media.
- Formation constants, lambda(max), and absorptivities for proton and metal complexes were determined.
Conclusions:
- SGCR exhibits distinct complexation behavior with bivalent metal ions across different pH ranges.
- SGCR is a reliable indicator for Cu(II) in weakly acidic solutions.
- SGCR is effective for detecting Cu(II), Zn(II), and Pb(II) in alkaline solutions.
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