Determination of the dissociation constants of some newly synthesized derivatives of 1,2,4-triazoline-3-thione in sodium hydroxide media
DOI:
https://doi.org/10.20450/mjcce.2006.289Keywords:
4-buthyl-5-octyl-2, 4-dihydro-3H-1, 2, 4-triazoline-3-thione, 4-allyl-5-octyl-2, 4- triazoline-3-thione, 4-phenyl-5-octyl-2, dissociation constant, UV spectroscopy, dissociationAbstract
The behaviour of some newly synthesized derivatives of 1,2,4-triazoline-3-thione (4-butyl-5-octyl-2,4-dihydro-3H-1,2,4-triazoline-3-thione, 4-allyl-5-octyl-2,4-dihydro-3H-1,2,4-triazoline-3-thione, 4-phenyl-5-octyl-2,4- dihydro-3H-1,2,4-triazoline-3-thione) was studied in aqueous sodium hydroxide solutions at different pH values with UV spectroscopy. The measurements were carried out immediately after preparation of the solutions, in the wavelength range from 190 nm to 360 nm, on a Varian Cary UV spectrophotometer. When the pH value of the solution increased from 5 to 9, the measured value of the absorbance decreased, while the absorption maximum shifted towards lower wavelengths. The dissociation constants were determined using the equation pKBH = logI + pH (I = c(BH)/c(B–)). The ionic strength of the solutions of 0.10 mol/dm3 was adjusted with addition of NaClO4. The calculations were derived from the values of the absorbance from the spectra obtained experimentally and from the spectra reconstructed by using the method of characteristic vector analysis (CVA). The absorbance values were measured at four wavelengths, on and around the absorption maxima for each investigated compound. Also, the pKBH values were determined graphically and they were in good agreement with those obtained numerically. The obtained values of the pKBH were in the range from 7.45 to 7.54 and they were in a good agreement with the expected ones for this kind of compounds.
References
Tandon, J. P. Barthwal, T. N. Bhall, K. P. Bhargava, Synthesis and Antiinflamatory Activity of Some New 3-(o- Substituted phenyl)-4-substituted-phenyl-5-alkyl/alkenylmercapto- 1H-1,2,4-triazoles, Indian J. Chem, 20 B 1017– 1022 (1981).
A. A. B. Hazzaa, I. M. Labouta, M. G. Kassem, Synthesis, Antibacterial and Antifungal Activity of 4-Substituted-5- Aryl-1,2,4-Triazoles, Arch Pharm. Chem. Sci. Ed., 11, (2) 43–57 (1983).
B. N. Goswami, J. C. S. Kataky, J. N. Baruah, Synthesis and Antibacterial Activity of 1-(-2,4-Dichlorobenzoyl)-4- substituted Thiosemicarazides, 1,2,4-Triazoles and Their Methyl Derivatives, J. Heterocyclic Chem., 21, 1225– 1229 (1984).
A. R. Jalilian, S. Sattari, M. Bineshmarvasti, A. Shafiee, M. Daneshtalab, Synthesis and in vitro antifungal and cytotoxicity evaluation of thiazolo-4H-1,2,4-triazoles and 1,2,3-thiadiazolo-4H-1,2,4-triazoles-1,2,4-4H-triazolesthiazoles- 1,2,3-thiadi-azoles, Arch. der Pharmazie, 333, 347–354 (2000).
N. Guelerman, S. Rollas, M. Uelgen, Synthesis and in vitro microsomal metabolism of 4-ethyl-5-(4- fluorophenyl)-2,4-dihydro-3H-1,2,4-triazole-3-thione and its potetial metabolities, Boll. Chim. Farm. 137, 5 140– 143 (1998).
S. Rollas, S. Büyüktimkin, A. Çevikbas, Platinum-mediated synthetic process for i4-1, 2,4-oxadiazolines, Arch. Pharm. (Weinheim), 324, 189–198 (1991).
A. R. Katritzky, C. W. Rees, Comprehensive Heterocyclic Chemistry, Vol. 5, Pergamon Press LTD, London, (1984).
L. Arman-Zubiċ, N. Perišiċ-Janiċ, M. Lazareviċ, A study of the behaviour of some substituted 1,2,4-triazoline-3- thiones in different media, J. Serb. Chem. Soc., 65(9) 619–630 (2000).
K. C. Ragenovic, V. Dimova, V. Kakurinov, D. M. Gabor, Synthesis of 1-Nonanoyl/octadecanoyl 1-4-substituted Thiosemicarbazides and substituted 1,2,4-Triazoles as biological active compounds, J. Hetrocyclic Chem., 40, 905–908 (2003).
A. Albert, E. P. Serjeant, The Determination of Ionization Constants, Chapman, London (1971).
M. Jankulovska, I. Spirevska, K. C. Ragenović, Behaviour of some newly synthesized substituted 1,2,4-triazoline-3-thiones in sulfuric acid media, Bull. Chem. Technol. Macedonia, 25, (1) 29–37 (2006).
T. E. Edward, S. C. Wong, Ionization of Carbonyl Compounds in Sulfuric Acid. Correction for Medium Effects by Characteristic Vector Analysis, J. Am. Chem. Soc., 99, 4229–4232 (1977).
C. A. Tsoleridis, D. A. Charistos, G. V. Vagenas, UV and MO Study on the Deprotonation of some 2-Aryl-cap delta^2-1,3,4-Oxadiazoline-5-thiones, J. Heterocyclic Chem., 34, 1715–1723 (1997).
Downloads
Published
How to Cite
Issue
Section
License
The authors agree to the following licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)
- Share — copy and redistribute the material in any medium or format
- Adapt — remix, transform, and build upon the material
- for any purpose, even commercially.
Under the following terms:
Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
- NonCommercial — You may not use the material for commercial purposes.