Preparation, Characterization, and Potentiometric Titrations of Some New Di-[3-(3-alkyl/aryl-4,5-dihydro-1H-1,2,4-triazol-5-one-4-yl)-azomethinphenyl] isophthalate/terephthalate Derivatives

3-Alkyl(Aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones ( 2) reacted with di-(3-formylphenyl) isophthalate ( 3) and di-(3-formylphenyl) terephthalate ( 6) to afford the corresponding 6 novel di-[3-(3-alkyl/aryl-4,5-dihydro-1H-1,2,4-triazol-5-one-4-yl)-azomethinphenyl] isophthalates ( 4) and 6 novel di-[ 3( 3-alkyl/aryl-4,5-dihydro-1H-1,2,4-triazol-5-one-4-yl)-azomethinphenyl] terephthalates ( 7), respectively. The acetylation reactions of compounds 4 and 7 were investigated, and 5 and 8 type compounds were obtained, respectively. The new compounds synthesized were characterized by using IR, H-1-NMR, C-13-NMR, and UV spectral data together with elemental analysis. In addition, to investigate the effects of solvents and molecular structure upon acidity, compounds 4 and 7 were titrated potentiometrically with tetrabutylammonium hydroxide in 5 non-aqueous solvents ( isopropyl alcohol, tert-butyl alcohol, N,N-dimethylformamide, acetone, and dimethyl sulfoxide). The half-neutralization potential values and the corresponding pK(a) values were determined for all cases.