The complexation of aqueous metal ions relevant to biological applications. 2. Reactions of copper(II) citrate and copper(II) succinate with selected amino acids

Abstract

Addition of amino acids, glycine, alanine, and serine, to poorly soluble copper(II) salts [copper(II) citrate and copper(II) succinate] all increase solubility of the copper(II) salts. Relative increases in solubility follow the polarity trend in the selected amino acids, with serine creating the greatest increase in solubility. Simultaneous equilibria calculations indicate the formation of mixed-ligand complexes in the copper(II) succinate -amino acid systems, the first time such mixed-ligand complexes have been observed. In contrast, mixed-ligand complexes are not predicted in the copper(II) citrate -amino acid systems. Potential bioavailability of copper(II) appears to be increased by the inclusion of amino acids in solution, roughly in parallel with the increase in solubility of the copper(II) salt. Therefore, measurement of the change in solubility caused by addition of amino acids to aqueous solution gives qualitative insight to the potential increase in bioavailability of the metal ion.

CuZn Electrodeposition in Cyanide-Free Electrolytes: Influence of Citrate/Metal ratio and pH on Simultaneous Copper and Zinc Reduction Kinetics and Alloy Composition Control

“…This limitation is lower than that for copper, given that it has a much lower cathodic peak current density. 11 A study of the effect of citrate on zinc reduction is not conducted, given that in the presence of both metals, citrate complexes mainly with copper ions, as seen previously in the UV-VIS results. Previous study indicates that pH is the main parameter with respect to reduction of zinc ions.…”

“…3 However, this kind of electrolyte operates at high current densities, meaning that zinc contents are systematically excessive and thus that the types of alloys produced are limited. 4 Moreover, as cyanide-based baths reveal many concerns as to their biological toxicity, an extensive search for satisfactory alternative electrolytes has been stimulated as follows: Pyrophosphate, 5 EDTA, 6 Sorbitol, 7 Nitrilotriacetic, 8 Pentadecafluorooctanoic acid, 9 Sulfate, 10 Glycine 4,11 Tartrate, 12 D-mannitol, 13 Choline acetate, 14 Ammonia solution, 15 Choline chloride, 16 Pyrophosphate-oxalate, 17 Triethanolamine, 18 Gluconate-Sulfate, 19 Glycerol-zincate, 20 Glucoheptonate, 21 Ionic liquid baths. 22 However, none of these has resulted in an industrial application, mostly because coating quality is always inferior compared to that obtained from cyanide complexes.…”

Preparation Of Mixed Ligand Complexes Of Cerium (III) Metal Using Multidentate Ligands And Investigation Of Their Physicochemical, Spectral, Thermal, And Antibacterial Properties.

“…In recent years, organic compounds with donor atoms like nitrogen (N), oxygen (O), and sulfur (S), coupled with active functional groups including -COOH, -NH2, -SH, and -OH, have attracted considerable attention. The combination of these elements has demonstrated the potential to form stable mixed ligand complexes, marking a significant development in the field [14][15][16][17]. Notably, these mixed ligand complexes have been found to exhibit catalytic properties in a variety of reactions, encompassing reduction, oxidation, oxidative cleavage, hydroformylation, and hydrogen peroxide decomposition.…”