New hydrophilic 3-hydroxy-4-pyridinone chelators with ether-derived substituents: synthesis and evaluation of analytical performance in the determination of iron in waters

Three new hydrophilic 3-hydroxy-4-pyridinone chelators containing ether-derived substituents were prepared by a more sustainable synthetic protocol that involves the use of microwave heating and commercially available amines, allowing the successful production of highly water soluble chelators with improved reaction yields and reaction times. Compared with parent 3-hydroxy-4-pyridinone ligands, the new compounds were obtained faster and in higher amounts, facilitating the scale up of the synthesis, which is crucial to produce these ligands and their respective iron(III) complexes for many biological, analytical and agricultural applications. Ligands were fully characterized by 1H and 13C Nuclear Magnetic Resonance, High Resolution Mass Spectrometry and Single Crystal X-ray Diffraction and their performance in the analytical determination of iron(III) in water samples was evaluated by sequential injection methods. The results obtained are scientifically relevant, pointing out the potential of the new and straightforwardly synthesized ligands as analytical reagents for determination of iron(III).