Abstract: The molecular structure modeling of imidazole and its derivatives was calculated by ab initio calculation method. The charge distribution of the optimal configuration was obtained. The NMR data of the calculated optimal configuration was in accordance with the actual operation data by nuclear magnetic resonance spectroscopy, which indicated that the built optimized molecular structure of imidazole and its derivatives was reasonable. According to the calculations of the molecular charge distribution, the alkalescence order of imidazole and its derivatives from strong to weak was in the order of 2-methylimidazole > 2-ethylimidazole > imidazole > 1-methylimidazole. Their pH values in aqueous solution and deacidification performance were determined. It was found that their pH values and acid-removal rates increased with the increase of alkalescence.

Key words: imidazole, derivatives, ab initio calculation method, charge distribution