Spectrophotometric Determination of Acidity Constants of Some Anthraquinone Derivatives in Methanol-Water Mixtures

Document Type : Research Article


Department of Chemistry, Razi University, Kermanshah, I.R. IRAN



A spectrophotometric method is used to determine the acidity constants of some derivatives of 9,10-anthraquinone in binary methanol-water mixtures at 25 °C. There is a linear inverse relationship between pKa of all acids and the mole fraction of methanol in the mixed solvent. The influence of substituents in the molecular structure on the ionization constants is discussed.  


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