The synthesis of bis(acetylacetonato) ethylenediamine and bis(acetylacetonato) ethylenediamine cobalt (II) complex was carried out. The Shiff base, acetylacetonato ethylenediamine was first prepared by refluxing 0.2 mole acetylacetone and 0.1 mole ethylenediamine in methanol. The complex was then prepared by refluxing 3mmole alkaline ethanolic solution of the Schiff base and 3mmole aqueous solution of cobalt (II) sulphate. The gray complex compound is hydrated, thermally stable as it decomposed at 240oC. A sharp band at 1606cm-1was observed which is for azomethine ( C=N ), this same band was also recorded in the bis(acetylacetonato)ethylenediamine cobalt (II) complex, which confirmed the coordination of the ligand to the cobalt (II) ion. The dissociation constant of the Schiff base conducted on a potentiometer established 12.20. Similarly, the stability constant for the formation of the complex was determined as 2.51 x 1011 and the ratio of coordinated ligands to the metal ion was found to be 1 : 1. Continuous variation analysis of the complex compound confirmed the 1 : 1 metal to ligand ratio. Molar conductance measurements showed that the complex compound prepared is a non electrolyte.

KEYWORDS: potentiometry, spectrophotometry, ethylenediamine complex.