We present a theory of the complexation of polyanions by divalent cations. The formation of both mono-and dicomplexes is possible. Monocomplexation locally inverts the charge of the polyelectrolyte and transforms it into a polyampholyte. The formation of a dicomplex creates a bridge between charged monomers. The complexation constants for mono and dicomplexation strongly decrease at high ionic ...

The interaction between benzo-15-crown-5 (B15C5), dibenzo-18-crown-6 (DB18C6), dibenzyl-daza-18crown-6 (DBzDA18C6), N-phenyl-aza-15-crown-5 (NPhA15C5) and dibenzopyridine-18-crown-6 (DBPy18C6) with π-acceptor 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) in chloroform solution was studied spectrophotometrically. The interaction of B15C5-DDQ and DB18C6-DDQ caused the formation...

A spectrophotometric study concerning the interaction between Trimethoprim (TMP) ,Sulfamethoxazole (SFMx), as n-donor and 2,3-dichloro-5,6- dicyano-P-benzoquinine (DDQ) and chloranilic acid (CA) as π-acceptor were been performed at 25°C. The results of interaction of CA and DDQwith TMP indicate the formation of a 1:1, 1:2, charge transfer complexes through non equilibrium reactions. In the case...

Using 1-octanol/octane mixed solvents, the extraction of aluminum(III), gallium(III) and indium(III) with 8-quinolinol was carried out at 25 degrees C. The formation constants of the respective metal(III) 8-quinolinolates in the aqueous phase and their partition constants between the mixed solvents and water were determined based on an analysis of the extraction equilibria. The relationship bet...

The significant shift in kinetic and equilibrium behavior of complex formation between Ni2 and 2-amino-cycloŽ . Ž . pentene-1-dithiocarboxylic acid ACDA in a solution of ionic surfactant cetyltrimethylammonium bromide CTAB was studied spectrophotometrically in 0.1 M NaBr medium at 30 C. A model based on distributions of ligand Ž . Ž . ACDA and complex Ni ACDA between aqueous and micellar pseudo...

Adult, male, unmedicated twins received antipyrine orally under carefully controlled environmental conditions. Relative contributions of genetic and environmental factors to 2-fold interindividual variations in rate constants for formation of the three main antipyrine metabolites were compared. Heritabilities for rate constants for formation of 4-hydroxyantipyrine, N-demethylantipyrine, and 3-h...

Protonation constants for the biologically-important thioamino acids cysteine (CSH), penicillamine (PSH) and glutathione (GSH), and the formation constants of their complexes with Cu(I), have been measured at 25 °C and an ionic strength of 1.00 mol dm(-3) (Na)Cl using glass electrode potentiometry. The first successful characterisation of binary Cu(I)-CSH and Cu(I)-GSH species over the whole pH...

the dependence on ionic strength of protonation of l-aspartic acid and its complexation withdioxouranium(vi) is reported in sodium perchlorate solution as a background salt. the measurementshave been performed at 25 ± 0.1 °c and various ionic strengths in the range 0.1 to 1.0 mol dm-3, using acombination of potentiometric and spectrophotometric techniques. the overall analysis of the present an...