ChemInform Abstract: Ternary Complexes in Solution. Part 28. Enhanced Stability of Ternary Metal Ion/Adenosine 5′-Triphosphate Complexes. Cooperative Effects Caused by Stacking Interactions in Complexes Containing Adenosine Triphosphate, Phenanthroline, a

1978 ◽  
Vol 9 (25) ◽  
Author(s):  
P. R. MITCHELL ◽  
H. SIGEL
Keyword(s):  
Adenosine Triphosphate ◽  
Metal Ion ◽  
Ternary Complexes ◽  
Stacking Interactions ◽  
Cooperative Effects ◽  
Ternary Metal ◽  
Enhanced Stability

Ternary Complexes in Solution, XXX Increased Stability Through Intramolecular Stacking in Mixed-Ligand Cu 2+ and Zn 2+ Complexes of 2,2′ -Bipyridyl and Carboxymethyl Aryl Derivatives

1979 ◽  
Vol 34 (2) ◽  
pp. 208-216 ◽  
Author(s):  
Etelka Farkas ◽  
Beda E. Fischer ◽  
Rolf Griesser ◽  
Volker M. Rheinberger ◽  
Helmut Sigel
Keyword(s):  
Metal Ion ◽  
Ternary Systems ◽  
Ternary Complexes ◽  
Mixed Ligand ◽  
Difference Spectra ◽  
Ternary Metal ◽  
The Stability ◽  
Stability Enhancement ◽  
Aryl Sulfide ◽  
Enhanced Stability

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.

scholarly journals Mixed Ligand Complexes of Transition Metal Ions with Selective Bio-Ligands in Surfactant-Water Mixtures

2019 ◽  
Vol 8 (2S11) ◽  
pp. 3182-3190
Keyword(s):  
Hydrogen Bonding ◽  
Transition Metal ◽  
Metal Ions ◽  
Chemical Speciation ◽  
Transition Metal Ions ◽  
Ternary Complexes ◽  
Mixed Ligand ◽  
Stacking Interactions ◽  
Micellar Media ◽  
Chelate Effect

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.

scholarly journals Using beryllium bonds to change halogen bonds from traditional to chlorine-shared to ion-pair bonds

2015 ◽  
Vol 17 (3) ◽  
pp. 2259-2267 ◽  
Author(s):  
Ibon Alkorta ◽  
José Elguero ◽  
Otilia Mó ◽  
Manuel Yáñez ◽  
Janet E. Del Bene
Keyword(s):  
Halogen Bond ◽  
Ion Pair ◽  
Ternary Complexes ◽  
Halogen Bonds ◽  
Bond Type ◽  
Cooperative Effects ◽  
Pair Bonds

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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