Abstract

SIERRA-ZENTENO, Araceli; GALAN-VIDAL, Carlos A.  and  TAPIA-BENAVIDES, Rafael. Acid-base equilibrium studies of 2-(aminomethyl)benzimidazole in aqueous solution. Rev. Soc. Quím. Méx [online]. 2002, vol.46, n.2, pp.125-130. ISSN 0583-7693.

The acid-base equilibrium constants of the 2-(aminomethyl)benzimidazole 2AMBZ in aqueous solutions have been determined at 25 °C by means of nuclear magnetic resonance spectroscopy (¹³C NMR), and corroborated by potentiometric and spectrophotometric techniques. pKa values were obtained from experimental data using the computer programs HypNMR, SUPERQUAD and SQUAD respectively, finding pKa₁ = 3.103 ± 0.079, pKa₂ = 7.624 ± 0.063 and pKa₃ = 12.540 ± 0.038 by NMR at variable ionic strength. Likewise, it was possible determine the deprotonation mechanism of 2AMBZ.

Keywords : 2-(aminomethyl)benzimidazole; pKa; HypNMR; SUPERQUAD; SQUAD.