Ternary complexes in solution. 42. Metal ion promoted hydrophobic interactions between nucleotides and amino acids. Mixed-ligand adeonsine 5'-triphosphate/metal ion(II)/L-leucinate systems and related ternary complexes

1983 ◽  
Vol 22 (6) ◽  
pp. 925-934 ◽  
Author(s):  
Helmut Sigel ◽  
Beda E. Fischer ◽  
Etelka Farkas
Keyword(s):  
Amino Acids ◽  
Metal Ion ◽  
Hydrophobic Interactions ◽  
Ternary Complexes ◽  
Mixed Ligand

scholarly journals Synthesis, Characterization and Antimicrobial Activity of Mixed-Ligand Complexes of Cu(II) with 1,2,4, Triazole and Amino Acids

2014 ◽  
Vol 6 (3) ◽  
pp. 487-496
Author(s):  
B. Anupama ◽  
C. G. Kumari
Keyword(s):  
Amino Acids ◽  
Antimicrobial Activity ◽  
Molecular Modeling ◽  
Elemental Analysis ◽  
Metal Ion ◽  
Ternary Complexes ◽  
Mixed Ligand ◽  
Conductivity Measurements ◽  
Tetrahedral Geometry ◽  
Molecular Modeling Studies

Mixed-ligand ternary complexes of Cu (II) metal ion with 1,2,4 triazole (TRZ) and amino acids (histidine (L1), threonine (L2), proline (L3) and hydroxyl proline (L4)) have been synthesized. The prepared ternary chelates were characterized by elemental analysis, IR and electronic spectra, as well as conductivity measurements. The general formula [Cu(TRZ)L]H2O were found for the ternary chelates containing TRZ. From the analytical and spectral data, the stoichiometry has been found to be 1:1:1 for all the complexes. A tetrahedral geometry has been proposed. Molecular modeling studies were also carried out to confirm the geometries of the complexes. All the new complexes were found to be active against bacteria. © 2014 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: http://dx.doi.org/10.3329/jsr.v6i3.16993 J. Sci. Res. 6 (3), 487-496 (2014)

scholarly journals Stability Constants of Mixed Ligand Complexes of Nickel(II) with Adenine and Some Amino Acids

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Naciye Türkel
Keyword(s):  
Aqueous Solution ◽  
Amino Acids ◽  
Ternary Complex ◽  
Coordination Complexes ◽  
Ternary Complexes ◽  
Mixed Ligand ◽  
Relative Stabilities ◽  
Binary And Ternary Complexes ◽  
Binary Complexes ◽  
Essential Trace Elements

Nickel is one of the essential trace elements found in biological systems. It is mostly found in nickel-based enzymes as an essential cofactor. It forms coordination complexes with amino acids within enzymes. Nickel is also present in nucleic acids, though its function in DNA or RNA is still not clearly understood. In this study, complex formation tendencies of Ni(II) with adenine and certain L-amino acids such as aspartic acid, glutamic acid, asparagine, leucine, phenylalanine, and tryptophan were investigated in an aqueous medium. Potentiometric equilibrium measurements showed that both binary and ternary complexes of Ni(II) form with adenine and the above-mentioned L-amino acids. Ternary complexes of Ni(II)-adenine-L-amino acids are formed by stepwise mechanisms. Relative stabilities of the ternary complexes are compared with those of the corresponding binary complexes in terms ofΔlog10⁡K,log10⁡X, and % RS values. It was shown that the most stable ternary complex is Ni(II):Ade:L-Asn while the weakest one is Ni(II):Ade:L-Phe in aqueous solution used in this research. In addition, results of this research clearly show that various binary and ternary type Ni(II) complexes are formed in different concentrations as a function of pH in aqueous solution.

scholarly journals Synthesis, Characterization, and Antibacterial Studies of Mixed Ligand Dioxouranium Complexes with 8-Hydroxyquinoline and Some Amino Acids

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Sunil S. Patil ◽  
Ganesh A. Thakur ◽  
Manzoor M. Shaikh
Keyword(s):  
Amino Acids ◽  
Magnetic Susceptibility ◽  
Metal Ion ◽  
Pathogenic Bacteria ◽  
Electronic Absorption Spectra ◽  
Thermal Studies ◽  
Electrical Conductance ◽  
Analysis Data ◽  
Mixed Ligand ◽  
Nmr Studies

Mixed ligand complexes of dioxouranium (VI) of the type [UO2(Q)(L)·2H2O] have been synthesized using 8-hydroxyquinoline (HQ) as a primary ligand and amino acids (HL) such as L-threonine, L-tryptophan, and L-isoleucine as secondary ligands. The metal complexes have been characterized by elemental analysis, electrical conductance, magnetic susceptibility measurements, and spectral and thermal studies. The electrical conductance studies of the complexes indicate their nonelectrolytic nature. Magnetic susceptibility measurements revealed diamagnetic nature of the complexes. Electronic absorption spectra of the complexes show intraligand and charge transfer transitions, respectively. Bonding of the metal ion through N- and O-donor atoms of the ligands is revealed by IR studies, and the chemical environment of the protons is confirmed by NMR studies. The thermal analysis data of the complexes indicate the presence of coordinated water molecules. The agar cup and tube dilution methods have been used to study the antibacterial activity of the complexes against the pathogenic bacteria S. aureus, C. diphtheriae, S. typhi, and E. coli.

Studies on the Mixed Ligand Complexes Involving Ligands of Biological Importance (Ni(II)/Zn(II)/Cd(II)-1,10-phenanthroline-2,2′ -bipyridyl-phenylalanine)

1977 ◽  
Vol 32 (4) ◽  
pp. 426-429 ◽  
Author(s):  
G. S. Malik ◽  
S. P. Singh ◽  
J. P. Tandon
Keyword(s):  
Ionic Strength ◽  
Metal Ion ◽  
Formation Constants ◽  
Ternary Complexes ◽  
Mixed Ligand ◽  
Mixed Ligand Complexes ◽  
Biological Importance

pH-metric studies on the interaction of Ni(II), Zn(II) or Cd(II) with 1,10-phenanthroline (Phen) or 2,2′-bipyridyl (Bipy) in the presence of phenylalanine (Phe) indicate the formation of 1:1:1 mixed ligand chelates and their monohydroxo derivatives. The addition of Phe takes place after the combination of Phen or Bipy with the metal ion is complete. The formation constants of the resulting complexes have been determined at 30 ± 1 °C and ionic strength (µ) = 0.1 KNO3 and the ternary complexes involving Phen are found to be more stable than the corresponding complexes involving Bipy as primary ligand.

Potentiometric Studies on Stepwise Mixed Ligand Complex Formation

1970 ◽  
Vol 25 (1) ◽  
pp. 22-26 ◽  
Author(s):  
G. Sharma ◽  
J. P. Tandon
Keyword(s):  
Complex Formation ◽  
Metal Ion ◽  
Mixed Ligand Complex ◽  
Iminodiacetic Acid ◽  
Formation Constants ◽  
Ternary Complexes ◽  
Mixed Ligand ◽  
Molar Ratio ◽  
Ligand Complex ◽  
Secondary Ligand

Stepwise mixed ligand complex formation is observed in the systems containing metal ion, iminodiacetic acid (IMDA) as primary ligand and one of the diamines, such as ethylenediamine (en), 1,2-propanediamine (1,2-pn) and 1,3-propanediamine (1,3-pn) as secondary ligands. Potentionmetric titrations indicate the formation of ternary complexes having a 1:1:1 molar ratio of metal ion to iminodiacetic acid to the secondary ligand. Initially, metal-IMDA (1:1) complex is formed in the lower buffer region prior to the formation of the ternary complex and the addition of the secondary ligand takes place only after the combination with the primary ligand is complete. Formation constants (log KMAB) of the ternary complexes have been calculated and the probable reaction mechanism is suggested. The order of stability in terms of metal ion has been found to be Cu (II) > Ni (II) >Zn (II) >Cd (II) and in terms of secondary ligand as 1,2-pn>en>1,3-pn.

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.

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