the complexation reactions of some transition metal ions and 2-aminopyridine (2-ampy) were studied potentiometrically in aqueous solution at µ=0.1 m and 25 °c. the overall stability constants log β’s of all species are obtained by computer refinement of ph-volume data with using the best computer program. several models were tested and the best one accepted according to the least sum of squared...

Interactions of certain amino acids with some metal ions have significant consequences in biological systems. Metal ions can act as co-factors in the regulation of enzymatic reactions. Interactions of metal ions with amino acid side chains or with different organic complexes is also essential for many biological events. In this study, the stability constants of 1 : 1 : 1 ternary complexes of Cu...

in the crystal structure of the title polymeric compound, [c42h38n6o33sr5.2(h2o)]n, five independent metal atoms (sr1-sr5) have different coordination environments. the sr1 and sr5 atoms are nine coordinated and feature distorted tricapped trigonal-prismatic and capped square-antiprismatic geometries, respectively. the rest srii atoms have eight coordination numbers. these units are connected v...

surfactant molecules are used as interesting tools to study the structure, function and stability of proteins. protonation states of amino acids may be changed in the presence of surfactants. in this work, using experimental observations and molecular dynamic simulation, the effects of sodium dodecyl sulfate on the acid dissociation constants of tryptophan was examined. the acid–base equilibriu...

The detailed solvation structure at the (110) surface of rutile (alpha-TiO2) in contact with bulk liquid water has been obtained primarily from experimentally verified classical molecular dynamics (CMD) simulations of the ab initio-optimized surface in contact with SPC/E water. The results are used to explicitly quantify H-bonding interactions, which are then used within the refined MUSIC model...

In the presence of iron (Fe), dissolved organic matter (DOM) may bind considerable amounts of arsenic (As), through formation of Fe-bridged As-Fe-DOM complexes and surface complexation of As on DOM-stabilized Fe-colloids (collectively referred to as As-Fe-DOM complexation). However, direct (e.g., chromatographic and spectroscopic) evidence and fundamental kinetic and stability constants have be...

the formation constants (log k), of the complexes formed between a number of amino acids(glycine , l-valine and l-alanine) with p-sulfonatocalix [4] arene at varying temperatures (25± 0.1to 65 ± 0.1 °c) in aqueous solutions and at natural ph of p-sulphonato-calix [4] arene (ph=3.2) bymeans of uv-vis spectrophotometeric technique have been investigated. at this ph the guestmolecule is in its cat...

synthesis and cation selectivity of 25, 27, dipropoxy-26, 28, di-propoxy 5, 11, 17, 23, ptert-butyl calix[4]arene are studied in acetonitrile solution. the stability constants of differentcomplexes of calixarene (as a ligand) with alkali metal cations are determined at 25 °c by usingspectrophotometric technique.on the basis of calculations, complexation of calixarene with cs+and li+ are more fa...

The charge-transfer complexation reaction between iodine and dibenzo- 18-crown- 6 (DB18C6) has been studied spectrophotometrically in chloroform solution at different temperatures. The resulting donor-acceptor complex was formulated as (DB 18C6…I )I . The spectrophotometric results , as well as the conductivity measurements, indicated that the gradual release of tiiodide ion from its contac...