<b>A triazole derivative as a new acid-base indicator</b>

Abstract

ABSTRACT ABSTRACT. In this study a new pH indicator, 3-benzyl-4-p-nitrobenzylidenamino-4,5-dihydro-1,2,4-triazole-5-on (BPNBAT), soluble in acetonitrile:water (1:4), was developed. The estimation of pH is possible either from the position of the absorption maxima or from the absorbance intensity at a constant wavelength. This feature allowed us to determine the basic transition range of the medium because BPNBAT is colorless at pH lower than 8.5 and showed strong yellow-green color with high extinction coefficient in the pH range of 8.5-10.1. pKa, pH at equivalent point and the molar absorptivity (in the aqueous medium at 380 nm) of BPNBAT are determined as 9.3, 8.3 and 8.8 x 10 3 L.mol, respectively. The color change at the transition range can be attributed to the resonance structures of BPNBAT. The triazole compound was compared with thymolphthalein for accuracy test. KEY WORDS KEY WORDS KEY WORDS

Significance of Triazole in Medicinal Chemistry: Advancement in Drug Design, Reward and Biological Activity

“…The effects of ibuprofen were outperformed by the effects of compound ( 13), (S)-1-(4amino-5-mercapto-4H-1,2,4-triazole-3-yl) ethanol, which showed considerable edema inhibition (91 %). Compound (14), which is (E)-5-(1-hydroxyethyl)-4-((pyridin-4-ylmethylene)amino))-2,4-dihydro-3H-1,2,4-triazole-3-thione, on the other hand, produced effects similar to ibuprofen (81 %) a result that was attributed to the presence of a primary amine. [36] Abdellatif and his colleagues synthesized many 1,2,4-triazole compounds and evaluated them for their pro-inflammatory, pro-electrogenic, and anti-cyclooxygenase activities.…”

“…It has been determined that five‐member heterocyclic nitrogen compounds are physiologically active and highly significant [9,10] . They are employed as colors, [13] insecticides, [12] corrosion inhibitors, [11] acid‐base indicators, [14] and other industrial chemicals [15] . Baldin was the first scientist to call the carbon nitrogen ring structure (C 2 N 3 H 3 ) after triazoles and to characterize their derivatives [16] …”

Redox Mechanism, Antioxidant Activity and Computational Studies of Triazole and Phenol Containing Schiff Bases

“…42 In addition, triazol derivatives are frequently used in laboratory as a color-based pH indicators. 43 The compounds of this class are pH sensitive at room temperature and display prominent changes in their photometric and redox responses upon variation in pH. It is likely that these compounds adopt different resonance structures based on acidity and alkalinity of solution system.…”