Quantum chemical study on the mechanisms of nucleophilic substitution of a nitro group in 2,4,6-trinitrotoluene and 1,3,5-trinitrobenzene |
| |
Authors: | V. N. Solkan S. A. Shevelev |
| |
Affiliation: | (1) N.D.Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky prosp., 117913 Moscow, Russian Federation |
| |
Abstract: | The semiempirical MNDO-PM3 method is employed for calculations of the enthalpies of formation of Meisenheimerortho- andipso--complexes of 1,3,5-trinitrobenzene (TNB) and 2,4,6-trinitrotoluene (TNT) with the methoxide ion in the gas phase and in water (using the pseudocontinual point-dipole solvation model). The calculated reaction enthalpies for the replacement of a TNB and TNT nitro group with a methoxy group reveal in principle the possibility for TNB to react with the methoxide ion in water by theSNAr mechanism through an intermediateipso--complex. In the gas phase this reaction can not follow theSNAr mechanism due to its strong endothermicity (20 kcal/mol). The analogous nucleophilic substitution of a TNT nitro group by a methoxy group may be suppressed by the faster formation of the stable trinitrobenzene anion.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1892–1897, November, 1993. |
| |
Keywords: | Meisenheimer complexes 1,3,5-trinitrobenzene 2,4,6-trinitrotoluene quantum chemical calculations MNDO-PM3 method reaction mechanism |
本文献已被 SpringerLink 等数据库收录! |
|