engleski

Synthesis and Fe(III)-binding properties of novel urea-catechol based ligand

Ditopic receptors are capable of binding both cations and anions at the same time on different sites in the molecule. Herein we present a new ditopic receptor L (Figure 1) with urea moiety which can bind vide variety of anions from ball-shaped halogen anions to acetate or phosphate. On the other hand, catechol units can strongly bind cations such as iron, copper, or aluminium. Tetradentade ligand L is water soluble, so most of the measurements were performed using this solvent. Compound L was synthesized by condensation of two catechol fragments and finally benzyl protections were cleaved from phenolic groups. The UV-Vis spectrophotometric measurements were carried out at different pH values with variations of iron(III) to ligand molar ratios. At higher pH values significant time-dependent changes in UV-Vis spectrum of L were observed indicating hydrolysis of the compound at these conditions. The NMR measurements are planned to access structural changes during this process. The stoichiometries and stability constants Fe(III)–L complexes of different stoichiometries present in aqueous solutions will be determined as well. We are also planning to study the formation of ternary Fe(III)-L-anion complexes.

urea ; ditopic ; catechol ; iron

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