scholarly journals Stability constants and thermodynamic parameters of cadmium complexes with sulfonamides and cephapirin

2018 ◽  
Vol 33 (1) ◽  
pp. 29
Author(s):  
M. S. Parihar ◽  
Farid Khan
Keyword(s):  
Stability Constant ◽  
Metal Complexes ◽  
Thermodynamic Parameters ◽  
Stability Constants ◽  
Cadmium Complexes ◽  
Electrode Processes ◽  
Diffusion Controlled ◽  
Higher Temperature ◽  
The Stability ◽  
And Diffusion

Stability constant (log 􀁠) and thermodynamic parameters of Cd2+ complexes with sulfonamide and cephapirin were determined by Polarographic technique at pH = 7.30 ± 0.01 and μ = 1.0 MKNO3 at 250°C. The sulfonamides were sulfadiazine, sulfisoxazole, sulfamethaxazole, sulfamethazine, sulfathiazole, sulfacetamide and sulfanilamide used as primary ligands and cephapirin as secondaryligand. Cd2+ formed 1:1:1, 1:2:1 and 1:1:2 complexes. The nature of electrode processes were reversible and diffusion controlled. The stability constants and thermodynamic parameters (􀂨G, 􀂨Hand 􀂨S) were determined. The formation of the metal complexes has been found to be spontaneous, exothermic in nature, and entropically unfavourable at higher temperature.

SODIUM CHELATES OF ETHYLENEDIAMINETETRAACETIC ACID

1963 ◽  
Vol 41 (1) ◽  
pp. 18-20 ◽  
Author(s):  
Vladimir Palaty
Keyword(s):  
Stability Constant ◽  
Stability Constants ◽  
Ethylenediaminetetraacetic Acid ◽  
Glass Electrode ◽  
Neutral Solution ◽  
Experimental Conditions ◽  
The Stability ◽  
Sensitive Method

The stability constant of the sodium chelate of EDTA was determined by means of a sodium-sensitive glass electrode. It appears that a hydrogen chelate of the formula NaHY2− is formed in the neutral solution of EDTA, but is very unstable. The stability constants, pKNaY = −2.61 and pKNaHY = 0.03, are comparable to the value obtained by Schwarzenbach and Ackermann under different experimental conditions by a less sensitive method.

scholarly journals Synthesis of Some 3d Metal Complexes of Quinine and their Toxicological Studies

1970 ◽  
Vol 25 ◽  
pp. 19-28 ◽  
Author(s):  
Adedibu C. Tella ◽  
Joshua A. Obaleya
Keyword(s):  
Stability Constant ◽  
Metal Complexes ◽  
Chemical Society ◽  
Cinchona Alkaloids ◽  
Albino Rats ◽  
Spectroscopic Techniques ◽  
Tetrahedral Geometry ◽  
Toxicological Studies ◽  
3D Metal Complexes ◽  
The Stability

Four metal complexes of antimalarials cinchona alkaloids; [Co(Quin)Cl3]-1,[Fe(Quin)Cl2H2O]SO3H2O-2, [Cu(Quin)ClSO4]∞-3 and [Cd(Quin)ClSO4]∞-4 have beensynthesized and characterized by elemental analysis, conductivity, magnetic moment, IR,UV-Vis and mass spectroscopic techniques. The tetrahedral geometry is assigned for all thefour complexes and the quinine ligand is protonated at quinuclidine N atom with thecoordination of the metal at quinoline N atom for all the complexes. Complexes 1 and 2have zwitterionic structures while complexes 3 and 4 are polymeric in nature with zig-zagextended chains (MCl- O -SO2- O -MCl- O –SO2---).Stability constant of the complexes were evaluated for the metal salts. The value of thestability constant (β) was found to be log 10.48, 9.92, 7.98 and 7.81 for Cu(II), Fe(III),Co(II) and Cd(II), respectively and the order of β was found to beCu(II)>Fe(III)>Co(II)>Cd(II). The stability constant data revealed that concomitantlyadministration of quinine with preparation containing these metals may reduce theirefficacy. Toxicological study was carried out by investigating the effect of administration ofthe complexes on alkaline phosphatase activity of kidney, liver and serum of Albino rats. Allthe examined four metal complexes were found to be non-toxic.Keywords: Quinine, stability constant, FTIR, MS, phosphates activity.DOI:  10.3126/jncs.v25i0.3280Journal of Nepal Chemical Society Volume 25, 2010 pp 19-28

scholarly journals SYNTHESIS OF NEW SUBSTITUTED PROCAINE HYDROCHLORIDE COMPOUNDS AND THEIR USE IN SPECTROPHOTOMETRIC DETERMINATION OF TETRACYCLINE HYDROCHLORIDE THROUGH DIAZOTIZATION-COUPLING REACTIONS

2021 ◽  
Vol 18 (39) ◽  
pp. 14-32
Author(s):  
Hind Sadiq Al-WARD ◽  
Mouayed Qassssim AL-ABACHI ◽  
Mohammed Rifaat AHMED
Keyword(s):  
Stability Constant ◽  
Thermodynamic Parameters ◽  
Coupling Reaction ◽  
Water Soluble ◽  
Procaine Hydrochloride ◽  
Effect Of Temperature ◽  
Basic Medium ◽  
Fast Method ◽  
The Stability

Background: Tetracycline is one of the most important antibiotics. It is used to treat many different bacterial infections. It is often used in treating severe acne, or sexually transmitted diseases such as syphilis, gonorrhea, or chlamydia. In some cases, tetracycline is used when penicillin or another antibiotic cannot be used to treat serious infections such as the ones caused by Bacillus anthracis, Listeria, Clostridium, Actinomyces. Aim: synthesized a new novel reagent used to determine TCH spectrophotometrically by using diazonium and coupling reaction. Methods: Four new substituted procaine derivatives were prepared by simple organic methods using aniline derivatives. A spectrophotometric approach was established for the micro-determination of TCH. The stoichiometry was investigated using mole ratio and continuous variation methods, and the stability constant was also estimated. The ΔG, ΔH, and ΔS were determined as thermodynamic parameters for evaluating the effect of temperature on the reaction. Results: Substituted procaine derivatives were prepared, and o-hydroxy procaine seems to be the best reagent used to determine TCH by diazotization and coupling reaction. The result was a yellow water-soluble dye with a maximum absorbance of 380 nm. The reaction conditions were studied and optimized. Beers law was obeyed over a concentration range (2.5–50) μg.mL-1 for TCH. The molar absorptivity was (14.4669.103) L.mol-1.cm-1, and the detection limit was (0.5052) μg.mL-1. The stoichiometry of the formed product was found 1:1 (o-hydroxyprocaine: TCH). The stability constant indicated that the product formed was stable, and the thermodynamic parameters showed that the diazonium salt reaction was preferred to occur at a low temperature. Conclusions: a simple, accurate, and fast method was developed to determine TCH in pure form and pharmaceuticals by coupling the TCH with a newly synthesized procaine derivative reagent (o-hydroxy procaine) in a basic medium.

Transferrin binding of Al3+ and Fe3+.

1987 ◽  
Vol 33 (3) ◽  
pp. 405-407 ◽  
Author(s):  
R B Martin ◽  
J Savory ◽  
S Brown ◽  
R L Bertholf ◽  
M R Wills
Keyword(s):  
Stability Constant ◽  
Blood Plasma ◽  
Stability Constants ◽  
Metal Ion ◽  
Equilibrium Dialysis ◽  
Ion Binding ◽  
Metal Ion Binding ◽  
Quantitative Studies ◽  
Intensity Changes ◽  
The Stability

Abstract An understanding of Al3+-induced diseases requires identification of the blood carrier of Al3+ to the tissues where Al3+ exerts a toxic action. Quantitative studies demonstrate that the protein transferrin (iron-free) is the strongest Al3+ binder in blood plasma. Under plasma conditions of pH 7.4 and [HCO3-]27 mmol/L, the successive stability constant values for Al3+ binding to transferrin are log K1 = 12.9 and log K2 = 12.3. When the concentration of total Al3+ in plasma is 1 mumol/L, the free Al3+ concentration permitted by transferrin is 10(-14.6) mol/L, less than that allowed by insoluble Al(OH)3, by Al(OH)2H2PO4, or by complexing with citrate. Thus transferrin is the ultimate carrier of Al3+ in the blood. We also used intensity changes produced by metal ion binding to determine the stability constants for Fe3+ binding to transferrin: log K1 = 22.7 and log K2 = 22.1. These constants agree closely with a revision of the reported values obtained by equilibrium dialysis. By comparison with Fe3+ binding, the Al3+ stability constants are weaker than expected; this suggests that the significantly smaller Al3+ ions cannot coordinate to all the transferrin donor atoms available to Fe3+.

scholarly journals Potentiometric and spectrophotometric studies of the complexation of Schiff-base hydrazones containing the pyrimidine moiety

2003 ◽  
Vol 68 (10) ◽  
pp. 729-749 ◽  
Author(s):  
H.S. Seleem ◽  
B.A. El-Shetary ◽  
S.M.E. Khalil ◽  
M. Shebl
Keyword(s):  
Schiff Base ◽  
Ionic Strength ◽  
Thermodynamic Parameters ◽  
Stability Constants ◽  
Elemental Analysis ◽  
Mass Spectra ◽  
Dissociation Constants ◽  
The Stability ◽  
Pyrimidine Moiety ◽  
Metal Ligand

Three Schiff-base hydrazones (ONN ? donors) were prepared by condensation of 2-amino-4-hydrazino-6-methylpyrimidine with 2-hydroxyacetophenone 2-methoxybenzaldehyde and diacetyl to yield 2-OHAHP, 2-OMeBHPand DHP respectively. The structures of these ligands were elucidated by elemental analysis, UV, IR, 1H-NMR and mass spectra. The metal?ligand stability constants of Mn2+, Fe3+,Co2+,Ni2+,Cu2+, Zn2+,Cd2+,UO22+ and Th4+ chelates were determined potentiometrically in two different media (75%(v/v) dioxane?water and ethanol?water) at 283, 293, 303 and 313 K at an ionic strength of 0.05 M (KNO3). The thermodynamic parameters of the 1:1 and 1:2 complexes were evaluated and are discussed. The dissociation constants of 2-OHAHP, 2-OMeBHP and DHPligands and the stability constants of Co2+, Ni2 and Cu2+ with 2-OHAHP were determined spectrophotometrically in 75 % (v/v) dioxane?water.

Discontinuous spectrocolorimetric titration method for determining stability constants of fulvic acid - iron complexes

Soil Research ◽  
1997 ◽  
Vol 35 (6) ◽  
pp. 1279 ◽  
Author(s):  
S. B. Pandeya ◽  
A. K. Singh
Keyword(s):  
Stability Constant ◽  
Stability Constants ◽  
Aqueous Media ◽  
Poultry Manure ◽  
Fulvic Acids ◽  
Titration Method ◽  
Binding Ability ◽  
Press Mud ◽  
Determining Factors ◽  
The Stability

The stability constants for the complexes formed between iron species existing in ambient soil environment and fulvic acids (FA) extracted from organic wastes like sewage sludge, farm yard manure (FYM), poultry manure, and press mud were determined in aqueous media of pH 5·0 and 8·5 by discontinuous spectrocolorimetric titration method. The values of stability constant (log K) of Fe–FA complexes estimated at pH 5·0 were 6·026, 6·212, 6·270, and 6·342 for FYM, sludge, poultry manure, and press mud, respectively. The respective values at pH 8·5 were 6·145, 6·276, 6·350, and 6·940. The order of the values of log K for different preparations of fulvic acids was press mud > poultry manure > sludge > FYM. The functional group contents, their pH of neutralisation, and electrostatic properties of the FA such as pKINT, pKm, and 0·868 nW, were found to be the determining factors for maximum binding ability of FA for metal cations and the stability constant of Fe–FA for different FA preparations. The basic assumptions and the limitations of the discontinuous spectrocolorimetric estimation of stability constants for Fe–FA are discussed.

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