Ternary complex formation of the copper(II), 2,2’-bipyridyne, 1,10’-phenanthroline and some bioligands

ABSTRACT

The formation of the binary Cu(II)-1,10ʹ-Phenanthroline (Phen, L) in aqueous solution was studied by means of electromotive force measurements (EMF). In addition, the Cu(II)-2,2ʹ-Bipyridine (Bipy, L) and Cu(II)-1,10ʹ-Phenanthroline ternary complexes were studied using the low molecular weight blood serum ligands: lactate (Lac⁻), Oxalate (Ox^2-), citrate (Cit^3-) and Phosphate (PO₄^3-), in aqueous medium, at 25°C and using 1.0 mol.dm⁻³ KNO₃ as ionic medium. The data obtained by potentiometric measurements were analysed using the LETAGROP least squares software. For the binary Cu(II)-1,10ʹ-Phenanthroline system the complexes [Cu(Phen)]²⁺, Cu(OH)₂(Phen) and [Cu₂(OH)₂(Phen)₂]²⁺ were detected. In the case of the ternary Cu(II)-L-Lac ^– system the species [Cu(L)(Lac)]⁺, Cu(Bipy)(Lac)(OH) and [Cu(Bipy)(Lac)(OH)2]⁻ were observed, for the Cu(II)-L-Ox^{2 –} system the complexes Cu(L)(Ox) and [Cu(L)(Ox)(OH)]⁻ were obtained whereas for Cu(II)-L-Cit^{3 –} system the species [Cu(L)(H₂Cit)]⁺, Cu(L)(HCit) and [Cu(L)(Cit)]⁻ were observed, and finally, in the Cu(II)-L-PO₄^{3 –} system the complexes[Cu(L)(H₂PO₄)]⁺, Cu(L)(HPO₄), [Cu(L)(PO₄)]− and [Cu(Bipy)(PO₄)(OH)]₂⁻ were detected.

KEYWORDS:

• Copper(II) complexes
• 2
• 2ʹ-bipyridyne
• 1
• 10ʹ-phenanthroline
• potentiometric studies
• speciation
• ternary complexes

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors are grateful for financing provided by the Decanato de Investigación y Desarrollo, from the Universidad Simón Bolívar;Decanato de Investigación y Desarrollo, from the Universidad Simón Bolívar [64565464].