PKA preperation of some diimines acids derived from benzil

The study is concerned with the preparation of four acids having diimines in a forms of Schiff bases as well as oxime in the same molecule. The acids prepared are identified by using UV, IR, NMR and melting points.<br /> The main object of the study is the determination of pKa of organic diimine acids under investigation, using a potentiometric method. It is confirmed in this study, that the1'potentiometric method is simple, fast, with an accuracy of ± 0.001 pKa unit and can be applied to more than one titrable proton in the molecule.<br /> The study shows that acidities of oxime benzilnylidenes having phenolic groups in o,m and p-positions is depend on donor-acceptor properties of oxime group. Also the acidity of oxime benzilnylidene-2-amino aniline is greater than the aliphatic amine.<br /> <br /> الخلاصة