Fac-mer equilibria of coordinated iminodiacetate (IDA2−) in ternary CuII(ida)(H−1B)− complex formation (B = imidazole, benzimidazole) in aqueous solution

Abstract

pH potentiometric and spectrophotometric investigations on the complex formation equilibria of Cu II with iminodiacetate (ida 2-) and heterocyclic N-bases, viz. imidazole and benzimidazole (B), in aqueous solution in binary and ternary systems using different molar ratios of the reactants indicated the formation of complexes of the types, Cu(ida), Cu(ida)(OH)-, (ida)Cu(OH)Cu(ida)-, Cu(B) 2+ , Cu(H-1 B) + , Cu(ida)(H-1 B)-, (ida)Cu(B)Cu(ida) and (ida)Cu(H-1 B)Cu(ida)-. Formation constants of the complexes at 25 ± 1° at a fixed ionic strength, I = 0⋅1 mol dm-3 (NaNO 3) in aqueous solution were evaluated and the complex formation equilibria were elucidated with the aid of speciation curves. Departure of the experimental values of the reproportionation constants (∆logK Cu) of ternary Cu(ida)(H-1 B)complexes from the statistically expected values, despite their formation in appreciable amounts at equilibrium, were assigned to fac(f)-mer(m) equilibria of the ida 2ligand coordinated to Cu II , as the N-heterocyclic donors, (H-1 B)-, coordinate trans-to the N-(ida 2-) atom in the binary Cu(ida) f complex to form the ternary Cu(ida) m (H-1 B)complexes.

A Study of the thermodynamic parameters (functions) of complexes formation of Sulfanilamid with metal ions and DL-Alanine by potentiometric method

“…The main benefit of this chemical element in these alloys is the inert protective oxide that forms on the surfaces in suitably oxidizing environments [38]. For full surface coverage by chromium oxide (Cr 2 O 3 ), more than 10% of Cr is required, and typically the range of Cr content is 15 -28%, for example in stainless steels [39]. This study deals with mixing complexes with the metal to form di complex and drug complexes with the metal and amino acid to obtain the tri complex [40].…”

Desarrollo y validación de soportes macroporosos para la separación de proteínas mediante cromatografía IMAC

“…Para ello, se hace circular una disolución de TRIS 50 mM pH 10 con el fin de retirar el imidazol que se encuentra en el interior de la columna, enlazada con el Cu 2+ inmovilizado, ya que el TRIS presenta gran afinidad por este ion metálico [180].…”