Abstract
We determined the binding constants for transition metal complexes of Cu2+, Co2+, Fe2+, Ni2+, and Zn2+ ions formed with the ligand picolinaldehyde-2-pyridylhydrazone (PapyH). Stoichiometry 2:1 (ligand: metal) was confirmed by single-crystal X-ray diffraction finding a propeller-like structure of the [Fe(Papy)2] compound. PapyH and the metal complexes were characterized by 1H NMR and UV-Vis spectroscopy respectively. The Cu2+ complex exhibited the highest stability constant, which was confirmed by competitive reaction of different metal ions with the ligand PapyH.
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•Synthesis of novel PapyH based metal complexes of Cu2+, Co2+, Fe2+, Ni2+ and Zn2+.•The formation of all metal complexes occurs in a ratio ligand: metal ion of 2:1.•Cu2+ exhibits the highest binding constant among the metal ions tested with K = 4.91 × 1010 M−2.•X-ray crystal structure of the [Fe(Papy)2] complex was determined.
Herein, we determined the binding constants for transition metal complexes of Cu2+, Co2+, Fe2+, Ni2+, and Zn2+ ions formed with the ligand picolinaldehyde-2-pyridylhydrazone (PapyH) using the Benesi-Hildebrand method. Stoichiometry 2:1 (ligand: metal) was previously determined by the Job’s method and confirmed by single-crystal X-ray diffraction finding a propeller-like structure of the [Fe(Papy)2] compound. PapyH and the metal complexes were characterized by 1H NMR and UV-Vis spectroscopy, respectively. The Cu2+ complex exhibited the highest stability constant, which was confirmed by competitive reaction of different metal ions with the ligand PapyH.