equilibria of the reaction of molybdenum(vi) with l-aspartic acid (asp) and l- glutamic acid(glu) have been studied by spectrophotometric measurements in mixed solvent systems at an ionicstrength of 0.2 mol/dm3 sodium perchlorate, employed (15, 20, 25, 30± 0.1°c) at ph ranges of 3.2to 5.5 with a high ratio of ligand to metal. the stability constants of the complexes and theresulting free energy...

The acidity constants of H(R —M P)~, where R —MP: = 4-nitrophenyl phosphate (NPhP2 ). phenyl phosphate (PhP2 ) and D-ribose 5'-m onophosphate (RibM P2 ). and the stability constants of the binary C u (R -M P ) com plexes w'ere determined by potentiometric pH titrations in aqueous solution and in 20. 30, 40 and 50% (v/v) dioxane-water mixtures. The solvent influence on the corresponding equilibr...

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...

The acidity constants of the compounds, including five-membered heterocyclic (pyrrole, thiophene, furan or thiazole) ring systems were determined at 25oC in aqueous solitions, applying UV-Vis spectroscopic method that uses absorbance diagrams,. In order to explain the pKa values obtained, also the molecule conformations of the bases and their corresponding conjugate acids were investigated, app...

The macro acidity constants valid for aqueous solutions of several adenine, guanine, and hypoxanthine derivatives are summarized. It is shown how the application of the corresponding constants, e.g., for 7,9-dimethyladenine, allows a quantification of the intrinsic acidic properties of the (N1)H0/+ and (N7)H+ sites via micro acidity constants, and how to use this information for the calculation...

The complexation reactions between 4-(2-pyridy1azo)-resorcinol and Cd ,H g and Pb io ns have been investigated in acetonitrile-dimethyEomamide mixtures at various temperatures using a spectrophotometric technique. The stoichiometry and the formation constants of the complexes formed in solution were calculated by computer refinement of absorbance-mole ratio data using nonlinear least-square ...

Equilibria of the reaction of molybdenum(VI) with L-aspartic acid (Asp) and L- Glutamic acid(Glu) have been studied by spectrophotometric measurements in mixed solvent systems at an ionicstrength of 0.2 mol/dm3 sodium perchlorate, employed (15, 20, 25, 30± 0.1°C) at pH ranges of 3.2to 5.5 with a high ratio of ligand to metal. The stability constants of the complexes and theresulting free energy...