scholarly journals NEW SPECTROPHOTOMETRIC METHOD FOR DETERMINING TITANIUM(IV) IN NATURAL OBJECTS

2021 ◽  
Vol 2021 (1) ◽  
pp. 44-51
Author(s):  
Adilya Jeyhun Ragimova ◽  
Vusala Ismayil Mardanova ◽  
Abel Maharram Maharramov ◽  
Khalil Jamal Nagiyev ◽  
Famil Musa Chyragov
Keyword(s):  
Stability Constants ◽  
Spectrophotometric Method ◽  
Alkaline Earth ◽  
Mixed Ligand ◽  
Binary Complex ◽  
Transition Elements ◽  
Foreign Ions ◽  
Mixed Ligands ◽  
The Stability ◽  
Twofold Excess

The article considers the interaction of Ti(IV) with 2, 3, 4-trihydroxy-3'-fluoroazobenzene (H3R) in the presence and absence of phenontroline (Phen), α, α'-dipyridine (α, α'-dip), and batophenontroline (B-phen) studied by using a spectrophotometric method. It has been found that the yield of the binary complex is maximum at pHopt = 5 (λmax = 428 nm), and for mixed-ligand complexes, pHopt = 3.0; 4.0; 3.5; λmax = 477 nm, 443 nm, 440 nm Ti(OH)2(H2R)-Phen, Ti (OH)2(H2R)-α, α'-dip and Ti(OH)2(H2R)-B-phen, respectively. It has been investigated that a twofold excess of the reagent is required for complete binding of titanium(IV) into the complex. The influence of time and temperature on the complexation is investigated. The stability constants of binary and mixed-ligand titanium(IV) complexes were calculated: logβ = 8.61 ± 0.05 for Ti(OH)2(H2R)2, logβ = 10.98 ± 0.06 for Ti(OH)2(H2R)-Phen, logβ = 10.85 ± 0.04 for Ti (OH)2(H2R)-α, α'-dip, logβ = 11.26 ± 0.03 for Ti(OH)2(H2R)-B-phen. The ratio of the reacting components in the binary complex is 1 : 2, and in the mixed ligands 1 : 2 : 2. The influence of foreign ions and masking substances on the titanium(IV) complexation with reagents has been studied. The determination is practically not interfered by alkaline, alkaline-earth and some transition elements. Due to these characteristics, the complexes can be used for defining titanium(IV) in different objects.

scholarly journals Stability Constants of Mixed Ligand Complexes of Transition Metal(II) ions with N-(2-hydroxybenzylidene)-2,3-dimethylaniline as Primary Ligand and N-(2-hydroxy-1-naphthylidene)-4-nitroaniline as Secondary Ligand

2011 ◽  
Vol 8 (2) ◽  
pp. 859-862 ◽  
Author(s):  
A. K. Mapari ◽  
K. V. Mangaonkar
Keyword(s):  
Ionic Strength ◽  
Transition Metal ◽  
Stability Constants ◽  
Ternary Complexes ◽  
Mixed Ligand ◽  
Mixed Ligand Complexes ◽  
Water Medium ◽  
Binary And Ternary Complexes ◽  
The Stability ◽  
Secondary Ligand

Binary and ternary complexes of the type M-Y and M-X-Y [M=Co(II), Ni(II), Cu(II) and Zn(II); X=N-(2-hydroxybenzylidene)-2,3-dimethylaniline and Y =N-(2-hydroxy-1-naphthylidene)-4-nitroaniline] have been examined pH-metrically at 27±0.5 °C and at constant ionic strength, μ=0.1 M (KCl) in 75:25(v/v) 1,4-dioxne-water medium. The stability constants for binary (M-Y) and ternary (M-X-Y) systems were calculated.

scholarly journals Electrometric Investigation of the Nature and Stability of Mixed Ligand Complexes of L-Ornithine and 1,10-Phenanthroline with Some Essential Metal Ions in Aqua-TBAB or PEG-400 Surfactant

2021 ◽  
Author(s):  
Atnafu Guadie Assefa ◽  
Molla Tefera Negash ◽  
Mulugeta Legesse Akele ◽  
Bewketu Mehari Workneh ◽  
Ayal Adugna Mesfin ◽  
...  
Keyword(s):  
Metal Ions ◽  
Stability Constants ◽  
Tetrabutylammonium Bromide ◽  
Mixed Ligand ◽  
Mixed Ligand Complexes ◽  
Essential Metal ◽  
Peg 400 ◽  
Chemical Models ◽  
Binary Complexes ◽  
The Stability

Abstract Background Despite the availability of information about the effect of aqua-surfactants media on the stability of binary complexes, data related to mixed ligand complexes of Phen and Orn with essential metals in aqua-surfactant medium is scarce. The aim of this study was, to determine the stabilities of the mixed ligand complexes of essential metal ions (Co2+, Ni2+, Cu2+) with Phen and Orn in aqua-TBAB and PEG-400 surfactants with an eye on the prediction of the bioavailability of the metal complexes. Results Complexes of some essential metal (M) ions (Co2+, Ni2+, Cu2+) of L-ornithine (L) and 1,10-phenanthroline (X) ligands in various concentrations (0.0–2.5% v/v) of aqueous tetrabutylammonium bromide (TBAB) or polyethylene glycol-400 (PEG-400) surfactant were synthesized pH-metrically at 298 K and 0.16 mol L− 1 ionic strength. The relative amounts of L:M:X were 2.5:1.0:2.5; 5.0:1.0:2.5; 2.5:1.0:5.0. The data acquisition of acid-base equilibria and determination of stability constants were performed using MINIQUAD75 algorithm. The distribution patterns of the complexes with varying pH and compositions of surfactants were presented from the plots of SIM run data. Conclusions The best fit chemical models were found to be MLXH, MLX2H in the lower pH, and MLX, ML2X in the higher pH ranges for all the metals. The logged values of stability constants decreased linearly with increasing concentrations of surfactants, indicating the dominance of electrostatic factors. The log of the disproportionation constant and the change in log values of the mixed ligand constant indicated additional stability of the mixed ligand complexes, compared to the parent binary complexes due to interactions outside the coordination sphere. This makes the mixed ligand complexes more amenable to metal ion storage and transport and threw light to have information on the less stable binary complexes easily bioavailability while the mixed ligand complexes could be stored and transported in the bio-fluids. Significant change on the magnitudes of the stability constants, high values of standard deviation and rejection of some of the proposed chemical models were observed due to pessimistic error, indicating the sufficiency of the models to represent the data and accuracy of the method employed.

scholarly journals Studies on biologically important copper(II) / manganese(II) / uranyl(II) – norvaline binary complexes

2008 ◽  
Vol 27 (2) ◽  
pp. 157 ◽  
Author(s):  
Brij Bhushan Tewari
Keyword(s):  
Stability Constants ◽  
Coordination Compounds ◽  
Metal Ion ◽  
Background Electrolyte ◽  
Binary Complex ◽  
Paper Strip ◽  
Ph Values ◽  
Binary Complexes ◽  
Stability Constants Of Complexes ◽  
The Stability

In coordination compounds studies, a knowledge of the magnitude of the stability constants of complexes is necessary for preliminary quantitative treatment. Described herein is a method that involves the use of advanced ionophoretic technique for the study of the equilibria in binary complex systems in solution. This method is based upon the migration of a spot of the metal ion on a paper strip at different pH values of background electrolyte containing 0.1 M perchloric acid and 0.01 M norvaline. A graph of pH against mobility provides information about the nature of the complexation and helps in calculating stability constants. Using this method, the stability constants of binary complexes metal(II) – norvaline have been determined to be (8.11 ± 0.02, 7.03 ± 0.09); (3.77 ± 0.11, 2.39 ± 0.07) and (7.59 ± 0.05, 6.17 ± 0.04) (log K values) for Cu(II), Mn(II) and UO2(II) complexes, respectively, at 35 ºC.

Paper ionophoretic technique in the study of biologically important beryllium(II) / cobalt(II)-homoserine binary complexes in solution

2010 ◽  
Vol 29 (2) ◽  
pp. 139
Author(s):  
Brij Bhushan Tewari
Keyword(s):  
Complex System ◽  
Stability Constants ◽  
Present Method ◽  
Background Electrolyte ◽  
Binary Complex ◽  
Paper Strip ◽  
Successive Addition ◽  
Binary Complexes ◽  
Quantitative Indication ◽  
The Stability

Quantitative indication of the process of forming a complex comes from the evaluation of the stability constants, which characterize the equilibria corresponding to the successive addition of ligands. A method, involving the use of paper electrophoretic technique is described for the study of binary complex system in solution. Present method is based upon the migration of a spot of metal ions on a paper strip at different pH’s of background electrolyte. A graph of pH against mobility gives information about the binary complexes and permits calculation of their stability constants. The first and second stability constants of [Be(II)-homoserine] and [Co(II)-homoserine] complexes were found to be (7.13 ± 0.02; 6.11 ± 0.09) and (4.27 ± 0.07; 3.47 ± 0.11) (logarithm stability constant values) for Be(II) and Co(II) complexes, respectively, at ionic strength of 0.1 mol/L and a temperature of 35 °C.

scholarly journals Study of Complex Formation Between Iodoquinol (IQ) and Co2+, Mn2+, Cd2+, Pb2+and Zn2+Cations in Binary Aqueous / Non-aqueous Solvent Using Spectrophotometry

2007 ◽  
Vol 4 (4) ◽  
pp. 581-586 ◽  
Author(s):  
A. Nezhadali ◽  
H. A. Hosseini ◽  
P. Langara
Keyword(s):  
Ionic Strength ◽  
Complex Formation ◽  
Stability Constants ◽  
Spectrophotometric Method ◽  
Formation Constants ◽  
The Other ◽  
Aqueous Solvent ◽  
The Stability ◽  
Complexation Reactions

The complexation reactions between iodoquinol and Co2+, Mn2+, Cd2+, Pb2+and Zn2+cations were studied in different DMF/H2O binary mixtures at the ionic strength of 0.1(using NaNO3).The spectrophotometric method was used for the determination of formation constants and the stoichiometries. The stoichiometry of the complexes is established 1:1 by Job's and mole ratio methods. It was found that the stability constants of the complex formed between the ligand (IQ) and the cations in the all cases increase with increasing of the non-aqueous solvent. In the most cases the maximum formation constants between Zn2+ion and IQ were obtained respect to the other cations.

scholarly journals Stability Constants of Mixed Ligand Complexes of Transition Metal(II) Ions with Salicylidene-4-methoxyaniline as Primary Ligand and 5-Bromosalicylidene-4-nitroaniline as Secondary Ligand

2011 ◽  
Vol 8 (4) ◽  
pp. 1765-1769 ◽  
Author(s):  
N. G. Nadkarni ◽  
K. V. Mangaonkar
Keyword(s):  
Ionic Strength ◽  
Stability Constants ◽  
Ternary Complexes ◽  
Mixed Ligand ◽  
Mixed Ligand Complexes ◽  
Water Medium ◽  
Binary And Ternary Complexes ◽  
Binary Complexes ◽  
The Stability ◽  
Secondary Ligand

Binary and ternary complexes of the type M-Y and M-X-Y [M = Mn(II), Ni(II), Cu(II) and Zn(II); X = salicylidene-4-methoxyaniline and Y=5-bromosalicylidene-4-nitroaniline] have been examined pH-metrically at 27±0.5 °C and at constant ionic strength, μ= 0.1 M (KCl) in 75 : 25(v/v) 1,4-dioxne-water medium. The stability constants for binary (M-Y) and ternary (M-X-Y) systems were calculated. The relative stability (Δ log KT) values of the ternary complexes with corresponding binary complexes for all the metal(II) ions in the present study found to be negative indicating that ternary 1:1:1 (M-X-Y) complexes are less stable than binary 1:1 (M-Y) complexes. In the ternary system studied, the order of stability constants of mixed ligand complexes with respect to the metal ions was found to be Cu(II) > NI(II) > Mn(II) > Zn(II); which is same as in the corresponding binary (M-Y) systems.

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