Al(III)-NTA-fluoride: a simple model system for Al-F binding with interesting thermodynamics.

Al(iii) complexes are extensively studied as [18F]fluoride carriers in positron emission tomography. However, our limited knowledge on their thermodynamic and kinetic properties has hindered efforts to easily prepare radiochemically pure compounds while simultaneously reducing the overall labeling time. Thus, to improve our understanding of fluoride binding to coordinatively unsaturated Al(iii) complexes, we investigated the ternary system Al(iii)-H3NTA-F- (H3NTA = nitrilo-triacetic acid) by NMR, potentiometry and X-ray diffraction.