Complex formation of nickel(II) ions with citric acid in aqueous solution: a potentiometric and spectroscopic study

1980 ◽  
Vol 33 (8) ◽  
pp. 1685 ◽  
Author(s):  
GR Hedwig ◽  
JR Liddle ◽  
RD Reeves
Keyword(s):  
Aqueous Solution ◽  
Citric Acid ◽  
Complex Formation ◽  
Spectroscopic Study ◽  
Hydroxy Group ◽  
Stability Constants ◽  
Spectrophotometric Study ◽  
Ph Range

From a potentiometric and visible spectrophotometric study of the nickel(II)-citric acid (H3L) system in the pH range 3-6, four complexes, NiL-, NiHL, NiH2L+ and NiL24-, have been characterized. Stability constants for the formation of these complexes have been determined at 25°C in 0.1 mol dm-3 KCl. The results suggest that the hydroxy group of citric acid is coordinated in the nickel-citrate complexes.

Schiff base equilibria. II. Beryllium complexes of N-n-butylsalicylideneimine and the hydrolysis of the Be2+ ion

1965 ◽  
Vol 18 (5) ◽  
pp. 651 ◽  
Author(s):  
RW Green ◽  
PW Alexander
Keyword(s):  
Aqueous Solution ◽  
Schiff Base ◽  
Complex Formation ◽  
Distribution Coefficient ◽  
Dilute Aqueous Solution ◽  
The Stability ◽  
Ph Range ◽  
Hydrolysis Of ◽  
Beryllium Complexes ◽  
Equilibria In Aqueous Solution

The Schiff base, N-n-butylsalicylideneimine, extracts more than 99.8% beryllium into toluene from dilute aqueous solution. The distribution of beryllium has been studied in the pH range 5-13 and is discussed in terms of the several complex equilibria in aqueous solution. The stability constants of the complexes formed between beryllium and the Schiff base are log β1 11.1 and log β2 20.4, and the distribution coefficient of the bis complex is 550. Over most of the pH range, hydrolysis of the Be2+ ion competes with complex formation and provides a means of measuring the hydrolysis constants. They are for the reactions: Be(H2O)42+ ↔ 2H+ + Be(H2O)2(OH)2, log*β2 - 13.65; Be(H2O)42+ ↔ 3H+ + Be(H2O)(OH)3-, log*β3 -24.11.

Spectroscopic study of azide complex formation of europium in aqueous solution

2002 ◽  
Vol 341 (1-2) ◽  
pp. 294-296
Author(s):  
Krzysztof Staninski ◽  
Małgorzata Kaczmarek ◽  
Marian Elbanowski
Keyword(s):  
Aqueous Solution ◽  
Complex Formation ◽  
Spectroscopic Study

scholarly journals Sensing Zn2+ in Aqueous Solution with a Fluorescent Scorpiand Macrocyclic Ligand Decorated with an Anthracene Bearing Tail

Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1355 ◽  
Author(s):  
Matteo Savastano ◽  
Matteo Fiaschi ◽  
Giovanni Ferraro ◽  
Paola Gratteri ◽  
Palma Mariani ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Complex Formation ◽  
Metal Ion ◽  
Equilibrium Constants ◽  
Macrocyclic Ligand ◽  
Fluorescence Emission ◽  
Zinc Complexes ◽  
Large Excess ◽  
Macrocyclic Ring ◽  
Ph Range

Synthesis of the new scorpiand ligand L composed of a [9]aneN3 macrocyclic ring bearing a CH2CH2NHCH2-anthracene tail is reported. L forms both cation (Zn2+) and anion (phosphate, benzoate) complexes. In addition, the zinc complexes of L bind these anions. The equilibrium constants for ligand protonation and complex formation were determined in 0.1 M NaCl aqueous solution at 298.1 ± 0.1 K by means of potentiometric (pH-metric) titrations. pH Controlled coordination/detachment of the ligand tail to Zn2+ switch on and off the fluorescence emission from the anthracene fluorophore. Accordingly, L is able to sense Zn2+ in the pH range 6–10 down to nM concentrations of the metal ion. L can efficiently sense Zn2+ even in the presence of large excess of coordinating anions, such as cyanide, sulphide, phosphate and benzoate, despite their ability to bind the metal ion.

A spectrophotometric study of the complex formation between cobalt(III) and trans-1,2-cyclohexanedinitrilotetraacetic acid (CyDTA)

1979 ◽  
Vol 57 (17) ◽  
pp. 2292-2296 ◽  
Author(s):  
Rita K. Hessley ◽  
Shoba Waykole ◽  
Robert L. Sublett
Keyword(s):  
Complex Formation ◽  
Stability Constants ◽  
Spectrophotometric Study ◽  
Higher Order ◽  
Order Complex ◽  
Spectrophotometric Methods ◽  
Investigation Result ◽  
Unique System ◽  
The Stability

An intriguing and unique system has been observed during the otherwise routine study of the cobalt(III) complex of trans-1,2-cyclohexanedinitrilotetraacetic acid (CyDTA). Using classical spectrophotometric methods to determine the stoichiometry and the stability of a complex, significant deviations from the predicted 1:1 complex were observed in a system buffered at pH = 4.6. It is postulated that in addition to the usual 1:1 complex, the propensity of the reactants to form complexes and the strong oxidizing conditions used in this investigation result in the formation of a second, higher order complex between Co(III) and CyDTA. When the concentration of CyDTA exceeds that of Co(III), the metal:ligand ratio for this complex is 1:2. A structure is proposed, and approximate stability constants of both complexes are discussed.

New Aspects of Complex Formation in the Gadolinium(III)–Citric Acid System in Aqueous Solution

2021 ◽  
pp. 1-36
Author(s):  
Valentina Yu. Ivanova ◽  
Igor D. Shurygin ◽  
Vladimir V. Chevela ◽  
Olga P. Ajsuvakova ◽  
Vyacheslav E. Semenov ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Citric Acid ◽  
Complex Formation ◽  
Acid System

scholarly journals A Spectrophotometric Study on Complex Formation in Dilute Aqueous Solution of Cupric Bromide.

1950 ◽  
Vol 4 ◽  
pp. 816-820 ◽  
Author(s):  
Reino Näsänen ◽  
Roland Lindner ◽  
Lars Gunnar Sillén ◽  
Max Rottenberg
Keyword(s):  
Aqueous Solution ◽  
Complex Formation ◽  
Spectrophotometric Study ◽  
Dilute Aqueous Solution

Uranium(VI) complexes with sugar phosphates in aqueous solution

2004 ◽  
Vol 92 (12) ◽  
Author(s):  
A. Koban ◽  
Gerhard Geipel ◽  
A. Roßberg ◽  
G. Bernhard
Keyword(s):  
Aqueous Solution ◽  
Complex Formation ◽  
Potentiometric Titration ◽  
Stability Constants ◽  
Complex Stability ◽  
Aqueous Systems ◽  
Ligand Ratio ◽  
Sugar Phosphates ◽  
Complex Stability Constants

SummaryThe complex formation in the aqueous systems of uranium(VI) with glucose 6-phosphate (G6P) and fructose 6-phosphate (F6P) were studied using potentiometric titration, TRLFS, and EXAFS. Two complexes with a uranyl-to-ligand ratio of 1:1 and 1:2 for both sugars were observed. Complex stability constants were determined by potentiometric titration for both complexes to be log βThe TRLFS measurements results show the UOUranium

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