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Published on: August 12, 2019
3-Hydroxy-2-(5-hydroxypentyl)-4H-chromen-4-one: a bidentate or tridentate iron(III) ligand?
Xiaole Kong1, Tao Zhou, Hendrik Neubert
1Pharmacy Department and Drug Control Centre/Mass Spectrometry Facility, King's College London, Franklin-Wilkins Building, Stamford Street, London SE1 9NH, UK.
Abstract:
The pK(a) value and iron affinity constants for 3-hydroxy-2-(5-hydroxypentyl)-4H-chromen-4-one 1 have been determined by spectrophotometry using aqueous methanol solutions. The extrapolated affinity constants beta(1), beta(2), and beta(3)( )()for iron(III) in aqueous solution were 9.95, 18.69, and 26.02, respectively, with a corresponding pFe(3+) value of 14.64. Job plot and MS spectra data demonstrated that the 3:1 species is favored at pH 7.0. These results indicate that 1 acts as a bidentate ligand when coordinated to iron(III).
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