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DOI: 10.1039/A802613K (Paper) Reference Section for: J. Chem. Res. (S), 1998, 704-705

Influence of Substituent on Tautomeric Equilibrium Constant in 5(6)-Substituted Benzimidazoles in the Gas Phase

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Ewa D. Raczyńska

Abstract

For 5(6)-substituted benzimidazoles, for which direct intramolecular interactions between the amidine moiety and substituent are absent, the pKT values calculated by the AM1 method are well reproduced by differences in the transmission of substituent electronic effects: pKT=(5.08±0.22)Δσ+(0.00±0.01); these differences result mainly from different transmission of resonance effect: pKT=(0.04±0.12)σα–(0.36±0.10)σF–(1.76±0.30)σR+(0.00±0.06).

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