Authors: NEDİME DÜRÜST, YAŞAR DÜRÜST, EMİNE ÖZGE GÖZLÜKAYA
Abstract: NH acidities of some 3-(p-substitutedphenyl)-1,2,4-oxadiazol-5(4H)-ones and 4-(p-substitutedphenyl)-1,2 \lambda^43,5-oxathiadiazole 2-oxides were determined in methanol by means of potentiometric titration with sodium methoxide. pK_a values of the title compounds calculated from the potentiometric data were interpreted on the basis of structural effects caused by para-substituted groups on the phenyl ring by plotting pK_a values versus Hammett \sigma_p^+ constants, which gave excellent linear correlations.
Keywords: Potentiometry, oxadiazol-5(4H)-one, oxathiadiazol 2-oxide, linear Hammett correlation
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