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Quercetin is one of the most common flavonoid compounds that are highly investigated
because of their antioxidant, antibacterial and antimutagenic activity. The characteristic
feature of flavonoids is related to their ability to make complexes with metal ions, so the
research of complexation mechanism is of crucial significance [1,2]. The studies allow
better understanding of reactions occurring in transport, reactivity as well as bioavailability
and toxicity of metal ions. Numerous experimental and computational investigations of
stoichiometry of the complexes and the modes of metal binding show different chelating
power of quercetin with respect to Al, Zn, Fe, Pb, Cu ions.
The presented research is a continuation of our previous study on adsorption of morin [3]
and quercetin (submitted) with TiO2 nanoparticles. The main experimental method applied in previous investigations and in this work is the Stark spectroscopy (electroabsorption)
allowing to determine the changes in permanent dipole moment and in polarizability, that characterize electronic density redistribution between the ground and excited state of the system. Our results show different modes of quercetin molecule binding to metal ions and provide quantitative measure of charge transfer contribution in electronic transitions.
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