the complexation reactions between diacetyl monooxime (damo), imidazole (him), histamine (hist) and histidine (his) with co2+, ni2+ and cu2+ were studied potentiometrically in aqueous solution at 25 °c and m= 0.5 m kno3. the overall stability constants log b's of species were obtained by computer refinement of ph-volume data using best computer program. several models were tested and, based on ...

The complexation reactions between Cu2+, Pd2+ and Ni2+ metal ions with promethazine (PM) in water or DMF were studied by the spectrophotometric methods at [(15, 25,35 and 45±0.1) °C]. The complexation process was optimized in terms of pH, temperature and contact time. The stoichiometry of the complex was found to be 1:1 (metal ion/ligand). The formation constants of the resulting complexes were...

The complexation of sodium molybdate with para-sulfonatocalix [4] arene was studied in thetemperature range from 20 to 40 °C and pH = 5.8 by spectroscopic method in water solution. Thestability constants of complexes were calculated by the multiwavelength analysis of spectral datausing SQUAD program. The equilibrium constant, spectroscopic data, molar absorptivities andconcentrations of all spe...

The formation of charge-transfer complexation between dibenzo-15-crown-5 (DB15C5) and benzo-12-crown-4 (B12C4) (Donor) and iodine is investigated spectrophotometrically in three chlorinated solvents,chloroform, dichloromethane (DCM) and 1,2-dichloroethane (DCE) solution at 25°C. The change in polarityof the solvent also doesn’t affect the stoichiometry of the complexes. Values of formation cons...

Stability or procaine and potassium salts of penicillin G in oleaginous Materials containing colloidal silica was studisd. The instability of penicillin G in these bases seeMed to be due pr!Marily to the surface acidity or the silica in conjunction with the ester constituents of oils. The stability or the peanut oil/silica/ penicillin G preparations could be !Mproved by reducing the surface aci...

In this study the binding abilities of 1,3-calix[4]biscrown-6 (L) toward Ba2+ and Ca2+ have beenestablished in methanol by spectrophotometric measurements at 25±0.1 °C and 0.01 M ionicstrength, and with using Specfit computer program; stability constants for 2 : 1, metal : ligandcomplexes has been estimated

Vapor adsorption is an important process influencing the migration and the fate of many organic pollutants in the environment. In this study, vibrational sum frequency generation (SFG) spectroscopy was used to study the adsorption of two surface acidity probe molecules, 4-picoline (pKa = 5.94) and piperidine (pKa = 11.24), onto the amorphous SiO2 surface. The adsorption of 4-picoline onto the s...

Abstract. The main aim of the paper is to study some quantitative aspects of the stability of the weak fixed point property for nonexpansive maps in l1 (shortly, w-fpp). We focus on two complementary approaches to this topic. First, given a predual X of l1 such that the σ(l1, X)-fpp holds, we precisely establish how far, with respect to the Banach-Mazur distance, we can move from X without losi...

in this work, we investigated the stability of molybdate-phosphonic acid (mpa) complex by density functionaltheory (dft) computations in six solvents with the dielectric constant ranging from 1.92 to 10.36. the methodsare used for calculations are b3lyp and b3pw9 i that have been studied in two series of basis sets: d95nand6-31+g (d,p) for hydrogen and oxygen atoms; lanl2dz for mo and phosphoru...