Formation Constants of Copper(II) and Zinc(II) with N-salicylideneanthranilic Acid in 50–50 Water–dioxane

1972 ◽  
Vol 50 (10) ◽  
pp. 1609-1611
Author(s):  
R. K. Mehta ◽  
R K Gupta
Keyword(s):  
Sodium Perchlorate ◽  
Formation Constants ◽  
Protonation Constants ◽  
Fair Agreement ◽  
Complex Species ◽  
Color Changes

Protonation constants of N-salicylideneanthranilic acid and formation constants of its Cu(II) and Zn(II)complexes have been studied potentiometrically in 50% dioxane (vol/vol) solutions (μ = 0.1 sodium perchlorate) at 30 ± 0.2 °C. The color changes observed during titrations have been related to the formation of different complex species in solution. The formation constants are in fair agreement with the Irving and Williams rule.

The formation constants of some metal complexes with 3-Acetyl-4-hydroxycoumarin, dehydroacetic acid, and their oximes

1971 ◽  
Vol 24 (5) ◽  
pp. 925 ◽  
Author(s):  
GCS Manku
Keyword(s):  
Metal Complexes ◽  
Sodium Perchlorate ◽  
Formation Constants ◽  
Ionic Concentration ◽  
Dehydroacetic Acid ◽  
Nitrogen Donors ◽  
Oxygen Donors

The formation constants (K1, K2, and β2) of the complexes of 3-acetyl-4- hydroxycoumarin (ahc) and dehydroacetic acid (dha) and their respective oximes, ahco and dhao, with iron(II), cobalt(II), nickel(II), copper(II), zinc(II), calcium(II), magnesium(II), cadmium(II), dioxouranium(VI), iron(III), aluminium(III), scandium(III), indium(III), yttrium(III), and lanthanon(III) ions (lanthanum to lutetium inclusive with the exception of promethium) have been determined pH-metrically at 35� in 50% v/v aqueous dioxan medium with 0.100M sodium perchlorate as the constant ionic concentration, using Calvin and Wilson's pH-metric technique. The trends in the formation constants of these complexes are discussed. It is observed that, except in the case of Co2+, Ni2+, and Cu2+ ions, for which chelation through nitrogen donors is more favoured, all other ions prefer coordination through oxygen donors.

Formation Constants of the Rare Earth Glyoxylate Complex Species

1964 ◽  
Vol 3 (5) ◽  
pp. 690-692 ◽  
Author(s):  
J. E. Powell ◽  
Y. Suzuki
Keyword(s):  
Rare Earth ◽  
Formation Constants ◽  
Complex Species ◽  
The Rare Earth

scholarly journals Determination of Protonation Constants of Viral Inhibitor, Aurintricarboxylic Acid in SDS and CTAB Micellar Media: A Potentiometric Study

2021 ◽  
Vol 33 (10) ◽  
pp. 2301-2305
Author(s):  
K. Bhargavi ◽  
P. Shyamala ◽  
G. Nageswara Rao
Keyword(s):  
Formation Constants ◽  
Protonation Constants ◽  
Micellar Media ◽  
Statistical Parameters ◽  
Chi Square ◽  
Aurintricarboxylic Acid ◽  
Viral Inhibitor ◽  
Chi Square Test ◽  
Anionic Micelle

Protonation constants of a viral inhibitor, aurintricarboxylic acid were determined using potentiometric method of data acquisition followed by chemometric modelling methods of analysis in the presence of two different kinds of micellar media, CTAB, a cationic micelle and SDS, an anionic micelle. MINIQUAD75 program was used for the determination of the plausible species and their corresponding formation constants at 303 ± 0.1 K and 0.01 M ionic strength. Five formation constants were identified corresponding to five ionizable hydrogens. Species concentration distribution diagrams were generated using Origin software. Best-fit chemical models were selected on the basis of statistical parameters like standard deviation (SD), U (sum of the squares of the residuals in mass balance equations) and chi-square test. It was found that the formation constants are lower in CTAB micellar medium while there is no significant change in the presence of SDS compared to aqueous medium.

scholarly journals Formation Constants of some Bivalent Metal Ion Chelates of N(2-hydroxy-1-naphthalidene) Anthranilic Acid (Schiff Base)

1971 ◽  
Vol 26 (9) ◽  
pp. 867-869 ◽  
Author(s):  
R. K. Mehta ◽  
V. C. Singhi ◽  
R. K. Gupta
Keyword(s):  
Schiff Base ◽  
Anthranilic Acid ◽  
Metal Ion ◽  
Formation Constants ◽  
Metal Chelates ◽  
Protonation Constants ◽  
Bivalent Metal ◽  
Transitional Metal

Protonation constants (log K1H and log K2H) of the Schiff base derived from 2-hydroxy-1-naphthaldehyde and anthranilic acid and, the formation constants of certain bivalent metal ion chelates have been determined potentiometrically in 50 per cent (vol./vol.) dioxan solutions (μ= 0.1 м NaClO4). The stabilities of these metal chelates are in the order, UO2 > Cu > Ni > Co > Zn > Cd, in which the sequence of those of first transitional metal ion chelates are in agreement with Irving and Williams order.

Equilibrium studies of triphenyltin(IV) complexes with glycine, glycyl-glycine, and glycyl-glycyl-glycine in different aqueous solutions of ethanol

2010 ◽  
Vol 88 (9) ◽  
pp. 877-885 ◽  
Author(s):  
Morteza Jabbari ◽  
Farrokh Gharib
Keyword(s):  
Hydrogen Bond ◽  
Stability Constant ◽  
Formation Constants ◽  
Least Squares Regression ◽  
Hydrogen Bond Donor ◽  
Equilibrium Studies ◽  
Hydrogen Bond Acceptor ◽  
Complex Species ◽  
The Stability ◽  
Glycyl Glycine

The protonation equilibria of glycine (gly), glycyl-glycine (gly-gly), and glycyl-glycyl-glycine (gly-gly-gly) and their formation constants with triphenyltin(IV) chloride were studied over a wide pH range (pH 1–11), using a combination of spectrophotometric and potentiometric methods at constant temperature (25 °C), different ethanol–water mixtures (50%–80%, v/v), and constant ionic strength (0.1 mol dm–3 NaClO4). Least-squares regression calculations are consistent with the formation of ph3SnHL+, ph3SnL, and ph3SnH–1L– complex species, where L– represents the fully dissociated form of each ligand. The stability constant of the formed complexes in different media were analyzed in terms of Kamlet, Abboud, and Taft (KAT) parameters. Single-parameter correlations of the stability constants versus α (hydrogen-bond donor acidity), β (hydrogen-bond acceptor basicity), and for π* (dipolarity/polarizability) are relatively poor in all solutions, but multi-parameter correlations represent significant improvements with regard to the single- and dual-parameter models. Linear correlation is observed when the experimental logβxyz values are plotted versus the calculated ones, while all the KAT parameters are considered. Also, the stability constant values of the formed complexes are determined in zero percent of organic solvent using the Yasuda–Shedlovsky extrapolation approach. Finally, the results are discussed in terms of the effect of solvent on complexation.

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