Kinetic and Thermodynamic Study of Proton Transfer Reactions of 1-Hydroxy-2,2-Dinitroethane: Establishing a Predictive Relationship between Tautomeric and Acidity Constants in Water.

ABSTRACT: The proton transfer reactions of the nitronate anion derived from 1-hydroxy-2,2-dinitroethane 1 with HCl and carboxylic acid buffers in aqueous solution at 25 °C are investigated through a comprehensive kinetic and thermodynamic analysis. The reaction mechanism is elucidated, allowing the determination of acidity constants for both O-protonation ( pKaNO2H$p K_{\text{a}}^{\left(\text{NO}\right)_{2} \text{H}}$  = 1.67) and C-protonation ( pKaCH$p K_{\text{a}}^{\text{CH}}$  = 3.78), which are among the weakest reported for nitroalkanes in water to date. The intrinsic rate constant (log k_o = 1.60), determined using the Marcus approach, is markedly lower than typical values reported for nitrile protonation, reflecting the exceptional resonance stabilization of the conjugate base by t

SUBMITTER: Khaldi R 

PROVIDER: S-EPMC12447123 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature