- Gazi University Journal of Science
- Vol: 27 Issue: 2
- Spectrophotometric determination of the acidity dissociation constants of symmetric Schiff base deri...
Spectrophotometric determination of the acidity dissociation constants of symmetric Schiff base derivatives
Authors : Gülşen Türkoğlu, Halil Berber, Müjgan Özkütük
Pages : 771-783
View : 18 | Download : 4
Publication Date : 2014-06-27
Article Type : Other
Abstract :800x600 In this study, the acidity constants of series symmetric Schiff base derivatives have been determined using the UV-visible spectrophotometric method at a temperature of 25(±0.1) °C. The deprotonated acidity constants ( p K a ) have been found to be associated with the deprotonation of phenolate oxygen. The first and the second protonated acidity constants ( p K a1 and p K a2 ) have been found to cause the protonation of the imine nitrogen atom for all molecules. The deprotonated acidity constants ( p K a ) were found for molecules 5 ( 9.088), 8 ( 9.848), 6 ( 10.243), 2 ( 10.2569), 3 (10.297), 1 (10.587), 7 ( 10.692) and 4 (10.804). The first protonation ( pK a1 ) was found for molecules 2 ( 3.432), 5 ( 4.207), 8 ( 4.612), 7 ( 4.758), 4 (4.995), 1 (5.288), 6 ( 5.606) and 3 (6.452). The second protonation ( pK a2 ) was found for molecules 2 ( -5.384), 8 ( -5.165), 5 ( -5.028), 7 ( -4.775), 4 (-4.518), 1 (-4.111), 6 ( -3.866) and 3 (-3.212). Normal 0 21 false false false TR X-NONE X-NONE MicrosoftInternetExplorer4Keywords : Spectrophotometric determination, Symmetric Schiff base, Acidity Dissociation Constants, UV-spectroscopy