FORMATION OF SCHIFF’S BASE (ACACEN) USING ETHYLENEDIAMINE AND EFFECT OF PH ON ZINC (II) ION ON COATED SILICA GEL BY COLUMN METHOD

ABSTRACT
Acetylacetone ethylenediamine (ACACEN) is a Schiff base resulting from the condensation of pentan-2,4-dione and 1,2-diaminoethane. Solid-phase extraction of Zn (II)  by column method in the pH range 1-12 have been studied in trichloromethane using acetylacetone ethylenediamine (ACACEN). Zn (II) extraction using 2% ACACEN in CHCl3 is sufficient or abundant in the pH of 5.0. The aqueous ACACEN shows a maximum absorption at 320nm.The Zn (II) complex has maximum absorption at 572nm.The acid dissociation constants of H2B (ACACEN) are obtained of by titrating with 0.179M NaOH and are found to be pKaiD = 11.55 and PKa2D = 11.55 corresponding to the formation of HB- and B2 respectively. pKaIDand pKa2D share the common value since H2B (ACACEN) has two ionizable hydrogen atoms located in the same chemical environment. Electronic spectrum of ACACEN suggests that ACACEN absorbs maximally in the ultraviolet regions of the spectrum and not in the visible region since it is not displayed in the spectrum. The physical modification of the silica gel using ACACEN has also been studied. The optimal pH value is found at the pH5.