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G.Allen Gnana Raj


Benesi-Hildebrand equation, binding constant, polyphenols, ruthenium (II)-polypyridyl complexes, structural effect


The binding of three Ru(II)-polypyridyl complexes with polyphenols (gallic acid and quercetin) have been studied in aqueous medium at pH 11 by means of absorption spectral technique. The absorption and emission maximum of this complexes are in the range of 451-457 nm and 612-626 nm respectively. The binding constant (Kb) for these reactions are determined from the Benesi-Hildebrand equation using absorption intensity data.

The observed binding constant values are sensitive to the nature of the ligand and the structure of the gallic acid and quercetin. Quercetin binds strongly with Ru(II) complexes than gallic acid owing to the presence of more phenolic –OH groups. Structural effect seems to play a vital role on the binding of the antioxidants with these complexes.


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