Formation constants and coordination thermodynamics for binary complexes of Cu(II) and some α-amino acids in aqueous solution

2010 ◽  
Vol 64 (2) ◽  
pp. 281-292 ◽  
Author(s):  
A. Seza Bastug ◽  
Seda E. Goz ◽  
Yesim Talman ◽  
Sinem Gokturk ◽  
Elvan Asil ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Amino Acids ◽  
Formation Constants ◽  
Binary Complexes

Equilibrium Studies of Binary and Ternary Complexes of Palladium(II) Involving Amino Acids

1993 ◽  
Vol 58 (5) ◽  
pp. 1103-1108 ◽  
Author(s):  
Mohamed M. Shoukry ◽  
Eman M. Shoukry
Keyword(s):  
Amino Acids ◽  
Relative Stability ◽  
Ternary Complex ◽  
Formation Constants ◽  
Ternary Complexes ◽  
Conductivity Measurements ◽  
Equilibrium Studies ◽  
Binary And Ternary Complexes ◽  
Binary Complexes

The formation constants of the binary and ternary complexes of palladium(II) with diethylenetriamine and amino acids as ligands have been determined potentiometrically at 25 °C in 0.1 M NaNO3 solution. The relative stability of each ternary complex was compared with that of the corresponding binary complexes in terms of ∆logK values. The mode of chelation was ascertained by conductivity measurements.

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 Characterization by Potentiometric Procedures of the Stability Constants of the Binary and Ternary Complexes of Cu(II) and Duloxetine Drug with Amino Acids

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Amal M. Al-Mohaimeed ◽  
Asma A. Alothman
Keyword(s):  
Amino Acids ◽  
Stability Constants ◽  
Formation Constants ◽  
Ternary Complexes ◽  
Planar Geometry ◽  
Binary And Ternary Complexes ◽  
Mass Spectral ◽  
Binary Complexes ◽  
Potentiometric Titration Method ◽  
The Stability

Potentiometric titration method has been used to define stoichiometries and stability constants of ternary complexes of Cu(II) with duloxetine (D) and some selected amino acids (L). The protonation constants of the ligands and the stability constants of the binary and ternary complexes of Cu(II) with the ligands were calculated from the potentiometric data using the HYPERQUAD program. The formation constants of the complexes formed in aqueous solutions and their concentration distributions as a function of pH were evaluated at 25°C and ionic strength 0.10 mol·L−1 NaNO3. Respective stabilities of ternary complexes have been determined compared with the corresponding binary complexes in terms of Δlog  K and %R.S. values. A novel binary and ternary duloxetine (D) drug with glycine and its Cu(II) complexes has been synthesized and characterized by several spectroscopic methods. Electronic spectra and magnetic susceptibility measurements reveal square planar geometry for both complexes. The elemental analyses and mass spectral data have justified the [Cu(D)(Gly)] and [Cu(D)Cl(H2O)] composition of complexes, where D = duloxetine and Gly = glycine. The EPR spectra of Cu(II) complexes support the mononuclear structures. Thermal properties and decomposition kinetics of Cu(II) complexes are investigated.

A colorimetric chemosensor for the sequential detection of copper ion and amino acids (cysteine and histidine) in aqueous solution

RSC Advances ◽  
2015 ◽  
Vol 5 (39) ◽  
pp. 31179-31188 ◽  
Author(s):  
Yong Sung Kim ◽  
Gyeong Jin Park ◽  
Seul Ah Lee ◽  
Cheal Kim
Keyword(s):  
Aqueous Solution ◽  
Amino Acids ◽  
Copper Ion ◽  
Sequential Detection ◽  
Colorimetric Chemosensor

A simple and selective colorimetric chemosensor was reported for the sequential detection of Cu2+, cysteine and histidine.

Fluorescence of the Complexes of 2-Methylnaphthoate and 2-Hydroxypropyl-α-, -β-, and -γ-Cyclodextrins in Aqueous Solution

2002 ◽  
Vol 56 (12) ◽  
pp. 1579-1587 ◽  
Author(s):  
Antonio Di Marino ◽  
Franscisco Mendicuti
Keyword(s):  
Aqueous Solution ◽  
Fluorescence Anisotropy ◽  
Intensity Ratio ◽  
Driving Forces ◽  
Emission Spectra ◽  
Formation Constants ◽  
Dielectric Constants ◽  
Additional Information ◽  
Fluorescence Techniques ◽  
Naturally Occurring

Fluorescence techniques were employed to study the inclusion complexes of 2-methylnaphthoate (MN) with 2-hydroxypropyl-α-cyclodextrin (αHPCD), 2-hydroxypropyl-β-cyclodextrin (βHPCD), and 2-hydroxypropyl-γ-cyclodextrin (γHPCD). Emission spectra of MN show two vibronic bands whose intensity ratio R is very sensitive to the polarity of the medium. The stoichiometry and formation constants of these complexes were investigated by obtaining R as a function of the cyclodextrin (CD) concentration. Results showed identical stoichiometry (1/1) for the three MN/αHPCD, MN/β-HPCD, and MN/γHPCD complexes. Formation constants at 25 °C were 780 ± 15, 2700 ± 130, and 165 ± 10 M−1, respectively. ΔH0 and ΔS0 were obtained from linear van't Hoff plots. Results reveal that the complexation of MN with αHPCD is enthalpy driven. With βHPCD, both the entropy and enthalpy terms favor the process, whereas the formation of the complex with γHPCD is entropically governed. The extrapolation of R at infinite CD concentration allows us to estimate the effective dielectric constants of the inner CD cavities, which are around 50, but which differ from their counterparts, the naturally occurring α-, β-, and γ-CDs. Fluorescence anisotropy, quencher lifetimes, and average lifetimes can also give additional information about the structure and driving forces accompanying the formation of such complexes.

Physico-chemical Characteristics of Amino Acids in Aqueous Solution of Amikacin Sulphate

2021 ◽  
Author(s):  
Poonam Chaudhary ◽  
◽  
Suvarcha Chauhan ◽  
Vivek Sharma ◽  
Kuldeep Singh ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Amino Acids ◽  
Chemical Characteristics ◽  
Physico Chemical
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