Ligand Exchange Reactions of a Monomeric Zirconium Carbonate Complex with Carboxylic Acids Studied by Extended X-ray Absorption Fine Structure, UV Absorption and Raman Spectrophotometry.

Ligand exchange reactions of a monomeric zirconium carbonate complex with carboxylic acids were studied by means of extended X-ray absorption fine structure (EXAFS), UV absorption spectrophotometry and Raman spectrometry. Three carboxylic acids, gluconic acid, and L-tartaric acid and citric acid, which are mono-, di- and tri-carboxylic acids, respectively, were employed in this study. These three carboxylic acids gave different spectral signatures and concentration dependences, respectively.

A monomeric [Zr(CO3)4](4-) complex in an ammonium zirconium carbonate aqueous solution studied by extended X-ray absorption fine structure, Raman and nuclear magnetic resonance spectroscopy.

The speciation of zirconium complexes in ammonium zirconium carbonate (AZC) solutions should be further studied in order to develop high-performance AZC complexes for use in elaborate industrial materials. Thus, the speciation and the structure of various zirconium species in ammonium zirconium carbonate solutions were investigated over a wide range of total carbonate and ammonium concentrations. By employing extended X-ray absorption fine structure analysis, and Raman and (13)C NMR spectroscopy, it was found that four carbonate ions coordinate bidentately to the zirconium ion.