scholarly journals Thermodynamic and Spectroscopic Studies of the Complexes Formed in Tartaric Acid and Lanthanide(III) Ions Binary Systems

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1121 ◽  
Author(s):  
Michal Zabiszak ◽  
Martyna Nowak ◽  
Zbigniew Hnatejko ◽  
Jakub Grajewski ◽  
Kazuma Ogawa ◽  
...  
Keyword(s):  
Tartaric Acid ◽  
Stability Constants ◽  
Binary Systems ◽  
Equilibrium Constants ◽  
Spectroscopic Studies ◽  
Luminescence Spectroscopy ◽  
Binary Complexes ◽  
Overall Stability ◽  
The Stability

Binary complexes of tartaric acid with lanthanide(III) ions were investigated. The studies have been performed in aqueous solution using the potentiometric method with computer analysis of the data for detection of the complexes set, determination of the stability constants of these compounds. The mode of the coordination of complexes found was determined using spectroscopy, which shows: Infrared, circular dichroism, ultraviolet, visible as well as luminescence spectroscopy. The overall stability constants of the complexes as well as the equilibrium constants of the reaction were determined. Analysis of the equilibrium constants of the reactions and spectroscopic data allowed the effectiveness of the carboxyl groups in the process of complex formation.

103Rh-NMR-Untersuchungen an Chloro-Bromo-Rhodaten(III) und Bestimmung der Stabilitätskonstanten im System [RhClnBr6-n]3-, n = 0-6 / 103Rh NMR Studies of Chloro-Bromo-Rhodates(III) and Determination of the Stability Constants in the System [RhCl„Br6-n]3-, n = 0-6

1989 ◽  
Vol 44 (11) ◽  
pp. 1402-1406 ◽  
Author(s):  
W. Kuhr ◽  
G. Peters ◽  
W. Preetz
Keyword(s):  
Nmr Spectroscopy ◽  
High Resolution ◽  
Stability Constant ◽  
Stability Constants ◽  
Trans Isomers ◽  
Nmr Studies ◽  
Downfield Shift ◽  
Overall Stability ◽  
The Stability

By 103Rh NMR spectroscopy the ten compounds of the system [RhCl„Br6_„]3-, n = 0-6 are identified by separate signals. A downfield shift of approximately 160 ppm is observed per substitution of Cl by Br, and the stereoisomers for n = 2, 3, 4 are separated by at least 4 ppm. From the relative intensities of the 103Rh signals in equilibrated solutions, whose total contents of Rh. Cl and Br are known, six individual stability constants are calculated. Their product gives the overall stability constant, indicating [RhBr6]3- to be 36,300 times more stable than [RhCl6]3-. On treatment of [RhBr6]3- with HCl cis/fac isomers are formed stereospecifically, whereas the reaction of [RhCl6]3- with HBr gives trans isomers, n = 2 and 4, containing 20—30% of the cis compounds; only mer-[RhCl3Br3] 3- is obtained pure. The high resolution spectra of [RhCl6]3- and [RhBr6]3- are exhibit five signals each, reflecting the intensity patterns of the most abundant isotopomers within [Rh35Cln37Cl6-n]3-, n = 2-6, and [Rh79Br„81Br6_„]3-, n = 1-5, respectively.

Extraction of strontium and barium salts by the nitrobenzene solution of dicarbolide in the presence of glymes

1985 ◽  
Vol 50 (3) ◽  
pp. 581-599 ◽  
Author(s):  
Petr Vaňura ◽  
Emanuel Makrlík
Keyword(s):  
Stability Constants ◽  
Organic Phase ◽  
Equilibrium Constants ◽  
Minor Role ◽  
Nitrobenzene Solution ◽  
Ligand Structure ◽  
Stability Constants Of Complexes ◽  
Separation Factors ◽  
The Stability ◽  
A Minor

Extraction of microamounts of Sr2+ and Ba2+ (henceforth M2+) from the aqueous solutions of perchloric acid (0.0125-1.02 mol/l) by means of the nitrobenzene solutions of dicarbolide (0.004-0.05 mol/l of H+{Co(C2B9H11)2}-) was studied in the presence of monoglyme (only Ba2+), diglyme, triglyme, and tetraglyme (CH3O-(CH2-CH2O)nCH3, where n = 1, 2, 3, 4). The distribution of glyme betweeen the aqueous and organic phases, the extraction of the protonized glyme molecule HL+ together with the extraction of M2+ ion and of the glyme complex with the M2+ ion, i.e., ML2+ (where L is the molecule of glyme), were found to be the dominating reactions in the systems under study. In the systems with tri- and tetraglymes the extraction of H+ and M2+ ions solvated with two glyme molecules, i.e., the formation of HL2+ and ML22+ species, can probably play a minor role. The values of the respective equilibrium constants, of the stability constants of complexes formed in the organic phase, and the theoretical separation factors αBa/Sr were determined. The effect of the ligand structure on the values of extraction and stability constants in the organic phase is discussed.

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