Preparation and Determination Studies of Cobalt(III) and Nickel(II) Ions With New Reagent 2-[(6-Nitro-2-benzothiazolyl)azo ]-1-naphthol (α-NBTAN)by Spectrophotometric Methods

Abstract

New heterocyclic azo dye reagent 2-[(6-Nitro-2-benzothiazolyl)azo]-1-naphtha(α-NBTAN=LH) and two complexes with Co(III) and Ni(II) have been prepared and characterized by using elemental analysis and vibrational spectra. A direct method has been developed for the spectrophotometric determination of microgram amounts of cobalt and nickel. This method sensitive, selective and rapid between Co(III) and Ni(II) with reagent (α-NBTAN) to form a color complexes. The molar absorptivity (Є) of the complexes are 2.51× 103 L. mol-1.cm-1 and 1.03 x103 L. mol-1.cm-1 at maximum absorptions ( λmax ) 629 nm and 625 nm for Co(III) and Ni(II) complexes respectively . The relative standard deviations, relative errors and recovery for Co(III) and Ni(II) complexes were : R.S.D%=1.16, 0.516, Re = 98.57, 97.14, D.L= 0.237, 0.537 and Erel % = 1.42, 1.12 respectively. The metal to ligand ratio (M : L) of complexes are (1 : 2) by using the mole ratio and slop ratio methods .