Journal ArticleDOI
Komplexone XXVI. Über die Koordinationstendenz von N-substituierten Iminodiessigsäuren
TLDR
In this paper, it was proved that the oxygen, the sulfur and the nitrogen atom of aliphatically bound HO, CH 3O, HS, CH3S, NH2, H2NCO, H3NCO are actually coordinated in this manner, raising thereby the stability of the metal complex considerably.Abstract:
Substituted iminodiacetic acids of the general formula RN(CH2-COOH)2 have been synthesized and their coordination tendency with 12 different metal cations investigated. The groups R of the 13 different complexing agents are tabulated on page 1147–1148 of this paper. Most of them carry donor atoms in such a position, that a third chelate ring may be formed when the anion of the iminodiacetic acid combines with the metal. It could be proved that the oxygen, the sulfur and the nitrogen atom of aliphatically bound HO, CH3O, HS, CH3S, (−)S, NH2, (−)OOC, H2NCO are actually coordinated in this manner, raising thereby the stability of the metal complex considerably. The carbonamide group coordinates probably by its oxygen atom rather than by its nitrogen atom. The negatively charged mercaptide sulfur is a very powerful donor for the heavy metals and there is a linear relation between the logarithm of the solubility product of the metal sulfide and the logarithm of the stability constant of the metal complex of (−)SCH2CH2N(CH2COO(−))2. The trimethylammonium group in of course lowers the complex stability, its effect however is much less important than expected. Also the cyano group in NCCH2-N(CH2-COO(−))2 weakens the metal binding much less than the addition of the proton to the nitrogen of the iminodiacetate group.read more
Citations
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Hydrogen ion buffers for biological research.
Journal ArticleDOI
A study of some problems in determining the stoicheiometric proton dissociation constants of complexes by potentiometric titrations using a glass electrode
TL;DR: In this paper, the effect of unknown junction potentials on acid dissociation constants has been investigated, with particular references to nitrilotriacetic acid (NTA) and ethylenediaminetetric acid (EDTA).
Journal ArticleDOI
Computer calculation of equilibrium concentrations in mixtures of metal ions and complexing species.
D.D. Perrin,I.G. Sayce +1 more
TL;DR: A method is described for calculating equilibrium concentrations of all species in multi-metal-multi-ligand mixtures from the pH of the solution, the total concentration of each metal and each complexing agent, and the relevant equilibrium constants (pK(a) values and stability constants).
Journal ArticleDOI
Isolation and some properties of human metallothionein.
Journal ArticleDOI
Komplexone XXIX. Ein grosser Chelateffekt besonderer Art
TL;DR: In this article, the stability constants of the 1:1 complexes of Ca2+, Cd2+ and Hg2+ have been determined for nearly the whole series of these complexons and a few values have been obtained also for the complexes of Mg2+, Sr2+, Ba2+, and Go2+.
References
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Journal ArticleDOI
637. The stability of transition-metal complexes
H. Irving,R. J. P. Williams +1 more
Journal ArticleDOI
Order of Stability of Metal Complexes
H. Irving,R. J. P. Williams +1 more
TL;DR: In this article, the stability of complexes of bivalent metal ions follows the order of the order in which they are formed, and it is shown that the stability is not correlated with the order.
Journal ArticleDOI
Komplexone XXV. Die polarographische Untersuchung von Austauschgleichgewichten. Neue Daten der Bildungskonstanten von Metallkomplexen der Äthylendiamin-tetraessigsäure und der 1,2-Diaminocyclohexan-tetraessigsäure
TL;DR: In this article, the polarogram of the metal complexes of Ethylenediaminetetraacetic acid and of 1,2-Diaminocyclohexane-tetracetic acid is described.
Related Papers (5)
Komplexone XXV. Die polarographische Untersuchung von Austauschgleichgewichten. Neue Daten der Bildungskonstanten von Metallkomplexen der Äthylendiamin-tetraessigsäure und der 1,2-Diaminocyclohexan-tetraessigsäure
Stability of Metal Chelates. I. Iminodiacetic and Iminodipropionic Acids
S. Chaberek,A. E. Martell +1 more