Synthesis and properties of transition and lanthanide complexes with benzyl monohydrazone-3-hydrazine- 4-benzyl-6-phenyl pyridazine ligand (BHP)

Abstract

Synthesis and characterization of benzyl-monohydrazone-3-hydrazino-4-benzyl-6-phenyl pyridazine (BHP) and its complexes with copper(II), nickel(II), cobalt(II), zinc(II), manganese(II), cadmium(II), thorium(IV), dioxyuranium(VI), samarium(III) and erbium(III) are presented. The protonation equilibrium of BHP ion and complex formation equilibrium with the metal ions have been studied by potentiometry in 75% (v/v) dioxane-water and 0.10M KNO3 at different temperatures (10, 20, 30 and 40°C). A series of mononuclear complexes [ML n ](1− z )+ (L− = BHP and n = 1 − z) were found in solution and their formation constants, enthalpies and entropies were determined.

The solid metal complexes and corresponding thermal products were elucidated by elemental analysis, conductance, IR and electronic spectra, magnetic moments, 1H NMR and TG-DSC measurements as well as by mass spectroscopy. The use of BHP as analytical reagents for the determination of copper(II), nickel(II) and cobalt(II) as well as extracting agents for these metal ions are discussed.