Coordination Studies of Al-EDTA in Aqueous Solution
Orkid Coskuner, Emily A. Jarvis
The degree of aluminum toxicity is based on its complexation with organic ligands. One of these complexes is the AlEDTA- (Al=aluminum, EDTA=ethylenediaminetetraacetate), of which the structure in aqueous solution has been debated based on x-ray absorption and NMR measurements with different interpretations proposing different coordination. In addition, there is a lack of consensus regarding the relationship of crystalline AlEDTA- to its geometry in solution. This debate must be resolved not merely for scientific interest but because the use of an incorrect coordination might lead to the wrong interpretation of bioactivity and kinetics data. In this work, we predict the coordination of Al in aqueous AlEDTA- by employing ab initio calculations and Car-Parrinello molecular dynamics simulations. Our results indicate that AlEDTA- favors Al in octahedral coordination in aqueous solution. Furthermore, the predicted crystalline and solution phase structures of AlEDTA- are similar and agree well with recent x-ray measurements, supporting the strong chelating nature of this metal-organic complex in aqueous solution.
Journal of Physical Chemistry B
Al, CPMD, DFT, EDTA, MD, metal-organic, water
and Jarvis, E.
Coordination Studies of Al-EDTA in Aqueous Solution, Journal of Physical Chemistry B
(Accessed June 5, 2023)