Quantum chemical studies of azoles 8. Effect of N(2)-methyl substituent on the calculated thermodynamic parameters of electrophilic substitution in tetrazole according to the elimination–addition scheme without preceding formation of N-protonated azolium salts

Abstract

Thermodynamic characteristics of electrophilic substitution reactions of 2-methyltetrazole and 2H-tetrazole proceeding according to the elimination–addition pathway (with the HO^– anion and hydroxonium ion as model agents) were compared on the basis of analysis of the results obtained by quantum chemical calculation performed using the DFT/B3LYP/6-31G(d,p) method and taking account of the specific solvation effects. Comparison with previous results for 1-methyltetrazole obtained by the same authors using the same method revealed probable reasons for the known lack of ability of 2-methyltetrazole to undergo electrophilic substitution reactions, particularly, the substantially lower polarity and HOMO and LUMO energies, that is, higher Mulliken electronegativity of 2-methyltetrazole compared with the 1-isomer.