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Full-Text Articles in Physical Sciences and Mathematics
The Protonation Constants Of Some Aliphatic Alkylamines In Ethanol-Water Mixtures, Esma Kiliç, Gülteki̇n Gökçe, Esi̇n Canel
The Protonation Constants Of Some Aliphatic Alkylamines In Ethanol-Water Mixtures, Esma Kiliç, Gülteki̇n Gökçe, Esi̇n Canel
Turkish Journal of Chemistry
Protonation constants of methyl-, ethyl-, propyl- and butylamines Were determined potentiometrically using an electrode system calibrated in concentration units of hydrogen ion in ethanol-water mixtures (10\% -80\% ethanol, v/v) at an ionic strength of 0.1 and at 25°C. The trend in the values of protonation constants of these aliphatic amines was explained in terms of the number of alkyl groups and solvent composition. The basicity orders were found to be NH_{3} < R_{3}N < RNH_{2} < R_{2}NH (R:-CH_{3}, -C_{2}H_{5}, -n-C_{3}H_{7} and --n-C_{4}H_{9}) in all the solvent mixtures studied.
Determination Of The Protonation Constants Of Some Substituted Salicylideneanilines By The Spectrophotometric Method In Ethanol-Water Mixtures, M. Abdülkadi̇r Akay, Esi̇n Canel, Esma Kiliç, Fi̇tnat Köseoğlu
Determination Of The Protonation Constants Of Some Substituted Salicylideneanilines By The Spectrophotometric Method In Ethanol-Water Mixtures, M. Abdülkadi̇r Akay, Esi̇n Canel, Esma Kiliç, Fi̇tnat Köseoğlu
Turkish Journal of Chemistry
Protonation constants of salicylideneaniline and methyl-, ethyl-, methoxy- fluoro-, chloro-, bromo- and iodo- substituted salicylideneanilines were determined by spectrophotomeric titrimetry in 10, 30, 50 and 70% ethanol-water mixtures at constant ionic strength and at 25^{o}C. The results obtained from this work were compared with those obtained using the potentimetric method. The difference between the results found with these two methods was approximately \pm $ 0.20 logK units. The spectrophotometric method was judged to be more suitable than the potentiometric method for halogen substituted salicylideneanilines with the low logK values and in the solvent mixture containing 10% ethanol, due to the …
Acid-Base Equilibria Of Some N-Substituted Thiophene-2-Carboxamidoximes In Non-Aqueous Media, Nedi̇me Dürüst, Yaşar Dürüst, İlknur Meri̇ç
Acid-Base Equilibria Of Some N-Substituted Thiophene-2-Carboxamidoximes In Non-Aqueous Media, Nedi̇me Dürüst, Yaşar Dürüst, İlknur Meri̇ç
Turkish Journal of Chemistry
The protonation constants of the amino nitrogens of some N-substituted thiophene-2-carboxamidoximes have been determined in acetic acid by means of potentiometric titration with perchloric acid. pK_{a} values of the title compounds were interpreted on the basis of structural effects due to the substituents and the main skeleton.