Ternary complexes in solution. 28. Enhanced stability of ternary metal ion/adenosine 5'-triphosphate complexes. Cooperative effects caused by stacking interactions in complexes containing adenosine triphosphate, phenanthroline, and magnesium, calcium, or zinc ions

1978 ◽  
Vol 100 (5) ◽  
pp. 1564-1570 ◽  
Author(s):  
Paul R. Mitchell ◽  
Helmut Sigel
1979 ◽  
Vol 34 (2) ◽  
pp. 208-216 ◽  
Author(s):  
Etelka Farkas ◽  
Beda E. Fischer ◽  
Rolf Griesser ◽  
Volker M. Rheinberger ◽  
Helmut Sigel

Abstract The stability constants of ternary Cu 2+ and Zn 2+ complexes, each of which contains 2,2′-bipyridyl and a carboxymethyl aryl sulfide, were determined in 50% aqueous dioxane. A comparison of the stability of these ternary complexes with those formed with simple carboxylates demonstrates an enhanced stability of the carboxymethyl aryl sulfide containing mixed ligand complexes. This enhanced stability is not due to a thioether-metal ion interaction, but due to an intramolecular aromatic stacking interaction between the aryl moiety of the carboxymethyl aryl sulfide and 2,2′-bipyridyl. Indeed, by UV difference spectra and by PMR measurements it is possible to show that a binary (metal ion-free) stacked adduct between the aromatic moieties of the two mentioned ligands is formed. Furthermore, by studying the binary and ternary systems of Zn 2+ or Cu 2+ , 2,2′-bipyridyl and hydrocinnamate, i.e. 3-phenylpropionate (-S-of carboxymethyl phenyl sulfide is replaced by -CH2-), it becomes obvious that the thioether moiety is not essential for the observation of an enhanced stability of the ternary complexes. PMR shift studies of 2,2′-bipyridyl/Zn 2+ /carboxymethyl aryl sulfide systems confirm the presence of stacking in the corresponding ternary complexes. Depending on the kind of the ternary metal ion complex the stability enhancement, due to the intramolecular stacking between the aromatic parts of the coordinated ligands, is between about 0.2 to 0.5 log unit.


2010 ◽  
Vol 7 (3) ◽  
pp. 1193-1201
Author(s):  
Baghdad Science Journal

In this research, the efficiency of low-cost unmodified wool fibers were used to remove zinc ion from industrial wastewater. Removal of zinc ion was achieved at 99.52% by using simple wool column. The experiment was carried out under varying conditions of (2h) contact time, metal ion concentration (50mg/l), wool fibers quantity to treated water (70g/l), pH(7) & acid concentration (0.05M). The aim of this method is to use a high sensitive, available & cheep natural material which applied successfully for industrial wastewater& synthetic water, where zinc ion concentration was reduced from (14.6mg/l) to (0.07mg/l) & consequently the hazardous effect of contamination was minimized.


2019 ◽  
Vol 8 (2S11) ◽  
pp. 3182-3190

Chemical speciation of ternary complexes of L-arginine and L-aspartic acid with essential transition metal ions was studied pH metrically. The following MLX, MLXH and ML2X ternary species are detected and reported in this paper. The existence of different ternary species is established from modeling studies using the computer program MINIQUAD75. The relative concentrations (M: L: X=1:2:2, 1:2:4, 1:4:2) and stabilities of the ternary species are compared with those of binary species. The extra stability associated with the ternary complexes is attributed to factors such as charge neutralization, chelate effect, stacking interactions and hydrogen bonding. Trend in variation of stability constants with the change in the mole fraction of the surfactant in various micellar media is explained on the basis of electrostatic and non-electrostatic forces. Distribution diagrams in relation to pH and plausible structures were presented.


2015 ◽  
Vol 17 (3) ◽  
pp. 2259-2267 ◽  
Author(s):  
Ibon Alkorta ◽  
José Elguero ◽  
Otilia Mó ◽  
Manuel Yáñez ◽  
Janet E. Del Bene

Dramatic synergistic cooperative effects between Be⋯F beryllium bonds and Cl⋯N halogen bonds in XYBe:FCl:N-base ternary complexes lead to changes in the halogen-bond type from traditional to chlorine-shared to ion-pair bonds.


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