Complexation of Al(iii) with gluconate in alkaline to hyperalkaline solutions: Formation, stability and structure

Attila Pallagi, Ágost Gyula Tasi, Gábor Peintler, Péter Forgo, István Pálinkó, Pál Sipos

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6 Citations (Scopus)


Contrary to suggestions in the literature, it has been proven that Al(iii) forms a 1:1 complex with gluconate (hereafter Gluc-) in strongly alkaline (pH > 12) aqueous solutions. The complex formation was proven via27Al and 1H NMR, freezing-point depression, polarimetric measurements as well as potentiometric and conductometric titrations. This complexation is a pH independent process, i.e., a condensation reaction takes place. The stability constant of the complex formed was derived from 1H NMR and polarimetric measurements, and was found to be log K = 2.4 ± 0.4. In the complex formed, Al(iii) has a tetrahedral geometry, and the Al(OH)4- is most probably statistically distributed between the alcoholate groups of the Gluc-.

Original languageEnglish
Pages (from-to)13470-13476
Number of pages7
JournalDalton Transactions
Issue number37
Publication statusPublished - Oct 7 2013


ASJC Scopus subject areas

  • Inorganic Chemistry

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