Synthesis and Spectrophotometric study of Cobalt, Nickel and Copper Ions Complexes with Some New Azo Dyes Containing 4,5– diphenyl imidazole .

Abstract

Three new organic heterocyclic azo dyes compounds which containing 4,5–diphenyl
imidazole group which were ( 6–NO2BTADI ) , ( 6–MBTADI ) and (6–MeBTADI ) have been
synthesized . The complexes of these reagents have been prepared with the metal ions Co (II) ,
Ni(II) and Cu(II) and were spectrally studied after fixing the optimum conditions. The study was
complated by investigating the UV–Vis spectra for solutions of forming complexes between
reagents and metal ions for a wide range of optimum pH at ( pH = 3.5 – 9.0 ) and the molar
concentrations that obey Lambert – Beer's law .
The mole ratios method of the metal: Ligand (M:L) has showed 1: 2 for all the prepared
complexes.The solutions of all these complexes prepared in the ethanol showed a bathochromic
shift in the visible spectral region, related to π →π * transitions of the semiaromatic ring
formed by the chelational coordination between the metal ions and the reagents.
The reagents and their complexes were characterized by C.H.N, IR spectra, UV-Vis
spectra, molar conductance measurements, magnetic susceptibility measurements and stability
constant. Flame atomic absorption and emission spectrophotometer was used to determine the
percents of the metal ion in the prepared complexes. The results are explained in the light of
these analysis.