Open AccessA study of the behaviour of some substituted 1,2,4-triazoline-3-thiones in different media
Author(s) -
Lucijana Arman-Zubic,
Nada U. Perišić-Janjić,
Marija Lazarevic
Publication year - 2000
Publication title -
journal of the serbian chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.227
H-Index - 45
eISSN - 1820-7421
pISSN - 0352-5139
DOI - 10.2298/jsc0009619a
Subject(s) - chemistry , sulfuric acid , protonation , dissociation (chemistry) , hydrolysis , sodium hydroxide , aqueous solution , acid dissociation constant , kinetics , dissociation constant , molecule , ionization , medicinal chemistry , inorganic chemistry , organic chemistry , ion , biochemistry , physics , receptor , quantum mechanics
The acid-base behaviour of 4-phenyl-5-(4-R-benzyl)-1,2,4-triazoline-3-thione (1(R = OH); 2(R = OC2H5)) was studied in aqueous sulfuric acid and sodium hydroxide solutions. Three ionisation equilibria of compound 1 (pKBH3+ = -4.64, pKBH2 = 7.50, pKBH- = 10.06) and two ionisation equilibria of compound 2 (pKBH2+ = -4.82, pKBH = 7.45) were found. The first equilibrium belongs to the protonation of 1,2,4-triazoline-3-thione, while the second belongs to the dissociation of the same part of the molecule. The third equilibrium represents the dissociation process of the phenolic OH group of compound 1. The kinetics of hydrolysis of compounds 1 and 2 were studied in high concentrated sulfuric acid solutions. The hydrolysis follows an irreversible first-order consecutive reaction path.