STANDARD GAS-PHASE FORMATION ENTHALPIES AND RELATIVE STABILITY OF С-ALKOXY-1,2,4-TRIAZOLES TAUTOMERIC FORMS AND ISOMERIC N-METHYL-C-METOXY-1,2,4-TRIAZOLES: QUANTUM-CHEMICAL CALCULATIONS
Abstract
The formation enthalpies of tautomeric forms of C-alkoxy-1,2,4-triazoles (alkoxy = OCH3, OC2H5, Oi-C3H7, Ot-C4H9) and isomeric N-methyl-C-methoxy-1,2,4-triazoles have been calculated by means of designed isodesmic and isomerisation reactions. The relative Gibbs energies for their tautomeric forms and isomers in aqueous solution have been calculated. N2-tautomers and isomers of C-alkoxy-1,2,4-triazoles wеre found to have the smallest values of formation enthalpy whereas N4-forms are less stable in gaseous phase. Increasing of electron donor properties of substituent leads to the stabilization of N2-tautomers in comparison with N1-tautomers. N1- and N2-tautomers and isomers have similar values of Gibbs free energy in aqueous solution. In contrast to gaseous phase, N1-derivatives of C-methoxy- and C-ethoxy-1,2,4-triazoles as well as N-methyl-C-methoxy-1,2,4-triazoles are more stable than corresponding N2-derivatives. This is due to higher polarity of N1-isomers in comparison with N2-ones. N4-derivatives are less stable in gaseous phase as well as in aqueous solution.
About the Authors
VADIM E. MATULIS
Научно-исследовательский институт физико-химических проблем, Минск
Belarus
Belarus
Y. I. GRIGORIEV
Научно-исследовательский институт физико-химических проблем, Минск
Belarus
Belarus
G. T. SUKHANOV
Институт проблем химико-энергетических технологий Сибирского отделения РАН, Бийск
Russian Federation
Russian Federation
I. A. KRUPNOVA
Институт проблем химико-энергетических технологий Сибирского отделения РАН, Бийск
Russian Federation
Russian Federation
O. A. IVASHKEVICH
Научно-исследовательский институт физико-химических проблем, Минск
Belarus
Belarus
References
1. Pharmaexpert [Electronic resource]. – Mode of access: http://pharmaexpert.ru/passonline.
2. Певзнер М. С., Самаренко В. Я., Багал Л. И. // Химия гетероциклических соединений. 1970. № 4. С. 568–571.
3. Nagao Y., Sano Sh., Ochial M. // Tetrahedron. 1990. Vol. 46. P. 3211–3232.
4. Суханов Г. Т., Суханова А. Г., Филиппова Ю. В. и др. // Ползуновский Вестн. 2013. № 1. С. 24–26.
5. Matulis Vadim E., Ivashkevich O. A., Gaponik P. N. et al. // J. Mol. Struct. (Theochem). 2008. Vol. 854. P. 18–25.
6. Frisch M. J. et al. // Gaussian 09, Revision A.02. Gaussian, Inc., Wallingford CT, 2009.
7. Becke A. D. // J. Chem. Phys. 1993. Vol. 98. P. 5648–5652.
8. Curtiss L. A., Raghavachari K., Redfern P. C. et al. // J. Chem. Phys. 1998. Vol. 109. P. 7764–7776.
9. Curtiss L. A., Redfern P. C., Raghavachari K. et al. // J. Chem. Phys. 1999. Vol. 110. P. 4703–4709.
10. Cances M. T., Mennucci B., Tomasi J. // J. Chem. Phys. 1997. Vol. 107. P. 3032–3041.
11. Ивашкевич О. А., Гапоник П. Н., Матулис Вит. Э. и др. // ЖОХ. 2003. Т. 73. С. 296–303.
12. Ивашкевич О. А., Матулис Вадим Э., Гапоник П. Н. и др. // ХГС. 2008. № 12. С. 1816–1828.
13. Wong M. W., Leung-Toung R., Wentrup C. // J. Am. Chem. Soc. 1993. Vol. 115. P. 2465–2472.
14. Mazurek A. P., Sadlej-Sosnowska N. // Chem. Phys. Lett. 2000. Vol. 330. P. 212–218.
15. Jimenez P., Roux M. V., Turrion C. // J. Chem. Thermodyn. 1989. Vol. 21. P. 759–764.
16. Trifonov R. E., Alkorta I., Ostrovskii V. A. et al. // J. Mol. Struct. (Theochem). 2004. Vol. 668. P. 123–132.
Review
Views: 820
Email this article 