ESR AND POLAROGRAPHY OF NITROAZOLES. 7. ANION-RADICALS OF ISOMERS OF N-METHYL-C-NITRO-1,2,4-TRIAZOLE

Abstract

The anion-radicals of N-methyl-substituted 3-nitro-1,2,4-triazole have been studied by polarography, ESR, and quantum-chemical methods. The difference in electrochemical behavior of the N-methyl isomers of 3‑nitro-1,2,4-triazole has been analyzed. The spin distributions in their anion-radicals have been investigated by quantum-chemical methods. The theoretical data obtained are in poor agreement with experiment. By varying the structural characteristics of the anion-radicals internal geometric parameters have been separated out which prove to have the greatest effect on spin distributions. Geometric structures were established for the investigated isomers by minimizing the functional describing the disagreement of the theoretical and experimental spin distributions on the magnetic nuclei. The calculated hyperfine structure constants for the magnetically active nuclei for the structures obtained were in good agreement with experiment. The influence of solvation effects on the electronic structure parameters of the nitrotriazole anion-radicals has been investigated. Hydrated complexes containing four molecules of water proved to be the most stable. Structural deformation of the solvated anion-radicals occurs in the same direction as on minimizing the functional.

Authors: T. I. Vakul'skaya, V. A. Shagun, L. I. Larina, and V. A. Lopyrev.

English Translation in Chemistry of Heterocyclic Compounds, 2000, 36 (2), pp 157-165

http://link.springer.com/article/10.1007/BF02283544