The first acidity scale to be established in a pure solvent other than water was the result of the pioneering work of Conant, Wheland, and McEwen in ether or ben~ene .~ During the past 20 years an ion-pair acidity scale covering an "effective pKa rangefrom about 15 to 40 has been developed in cyclohexylamine (CHA),6 and similar studies in other low-dielectric-constant solvents including 1,2-dim...

the acid-base equilibria of glycine have been studied in different aqueous solutions of 1,4-dioxane(0-50 % by v/v) using potentiometric method. in this study, the macro and micro protonationconstants of the amino acid and its tautomeric constant have been determined at 25 °c and constantionic strength 0.1 mol dm-3 (nacl). the protonation and the tautomeric constants of glycine indifferent binar...

We have computed the free energy profiles of the deprotonation reactions of lumiflavin in the semiquinone and fully reduced oxidation states using constrained DFT-based molecular dynamics simulations. In the semiquinone state, the N5 nitrogen atom and the N1 nitrogen atom can become protonated. We find, in agreement with experiment, that the N5 site is the predominant proton acceptor in the sem...

The acid-base equilibria of glycine have been studied in different aqueous solutions of 1,4-dioxane(0-50 % by v/v) using potentiometric method. In this study, the macro and micro protonationconstants of the amino acid and its tautomeric constant have been determined at 25 °C and constantionic strength 0.1 mol dm-3 (NaCl). The protonation and the tautomeric constants of glycine indifferent binar...

Accurate prediction of thermodynamic constants of chemical reactions in solution is one of the current challenges in computational chemistry. We report a scheme for predicting stability constants (log β) and pKa values of metal complexes in solution by means of calculating free energies of ligand- and proton-exchange reactions using Density Functional Theory calculations in combination with a c...

Acid–base chemistry of clay minerals is central to their interfacial properties, but up to now a quantitative understanding on the surface acidity is still lacking. In this study, with first principles molecular dynamics (FPMD) based vertical energy gap technique, we calculate the acidity constants of surface groups on (010)-type edges of montmorillonite and kaolinite, which are representatives...