Mixed-ligand complex formation equilibria of nickel(II) with picolinic acid and some amino acids (glycine, α-alanine, β-alanine, and proline) studied in 1.0 mol·dm− 3 NaCl at 25 °C

In the present work the chemical speciation of ternary complexes systems formed by VO2+ ion with picolinic acid and the amino acids = α-alanine (HαAla), glycine (HGly), serine (HSer), threonine (HT...

Speciation studies of binary and ternary complexes formed with oxidovanadium(IV) ion picolinic acid and some amino acids

In this work, the ligand 2-methylquinoline-8-carboxylic acid (HL) was prepared using a modification of a previous protocol, and its protonation constants were studied. The stability constants of th...

Binary and ternary nickel (II) complexes with 2-methylquinoline-8-carboxylic acid and some amino acids

In this work we report the results of a speciation study on the ternary complexes present in the ternary Ni(II)- 1,10 phenanthroline (Phen)-amino acids and Ni(II)- 2,2-bipyridine (Bipy)-amino acids...

Ternary complex formation of the nickel(II), 2,2’-bipyridine, 1,10’-Phenanthroline and some aminoacids

In this work, we present the results from a chemical speciation study of binary and ternary complexes formed by Ni(II) ion with picolinic acid and the amino acids = Arginine (HArg), Tryptophan (HTr...

Binary and ternary nickel (II) complexes with picolinic acid and several amino acids

In this paper we report the formation of binary and ternary nickel(II) complexes involving dipicolinic acid (H2Dipic) as the primary ligand and some selected amino acids {glycine (HGly), ⍺-alanine (H⍺-Ala), β-alanine (Hβ-Ala) and proline (HPro)} as secondary ligands. These complexes were studied at 25 °C by means of electromotive force measurements, emf(H), using 1.0 mol⋅dm−3 NaCl as the ionic medium. The experimental data were analyzed by means of the computational least-squares program LETAGROP, taking into account hydrolysis of the nickel(II) cation and the acid/base reactions of the ligands whose equilibrium constants were kept fixed during the analysis. In the study of the binary nickel(II)–amino acids systems the species [NiL]+, NiL2 and [NiL3]− were observed, and in the case of the ternary nickel(II)–dipicolinic acid–amino acids systems the complexes Ni(Dipic)HL, [Ni(Dipic)L]− and [Ni(Dipic)L(OH)]2− were observed. The respective stability constants were determined, and the species distribution diagrams, as a function of pH, are briefly discussed.

Complexation Equilibria and Determination of Stability Constants of Binary and Ternary Nickel(II) Complexes with Amino Acids (Glycine, α-Alanine, β-Alanine and Proline) and Dipicolinic Acid as Ligands

Rosana Hernández

Papers

Complexation Equilibria and Determination of Stability Constants of Binary and Ternary Nickel(II) Complexes with Amino Acids (Glycine, α-Alanine, β-Alanine and Proline) and Dipicolinic Acid as Ligands