Synthesis and Physiochemical Studies of Some Mixed Schiff Bases Complexes

Five mixed Schiff bases complexes of Co(II), Ni(II), Cu(II), Zn(II) and Fe(III) ions with two different Schiff bases, first Schiff base namely{2-((2-hydroxy-1-phenylethylidene)amino)-3-(4-hydroxyphenyl)propanoic acid} derived from the reaction of 2-hydroxyacetophenone and tyrosine as main ligand (HL1) and the second one namely {4-((2-(2,4-dinitrophenyl)hydrazono)methyl)-N,N-dimethylaniline} is formed from the condensation of 4-dimethylaminobenzadehyde and 2,4-dinitrophenylhydrazine as  a  second ligand (HL2) were prepared. The Synthesized Schiff bases and their mixed Schiff base complexes were subjected to several physiochemical tools; in terms, CHN elemental analyses, molar conductivity, infrared, proton nuclear resonance, electronic, mass and electron paramagnetic resonance spectra. The CHN elemental analysis results showed the formation of the Schiff bases and their complexes in 1:1:1[M:L1:L2] ratio. The molar conductivity values revealed that Co(II), Ni(II), Cu(II) and Zn(II) mixed Schiff base complexes to be electrolytes due to the existence of sodium ion outside the complexes, but the iron(III) mixed Schiff base complex is neutral confirming the presence of non-electrolytic natured. The infrared spectral data of the mixed Schiff base complexes exhibited chelation behavior between the metal ions and the Schiff bases through the active groups presented in the Schiff bases such as nitrogen atom of the azomethine and oxygen atom of the hydroxyl  group. The signals which obtained from the 1HNMR spectra of the Schiff bases and their Zn(II) complex supported the chelation between the Zn(II) ion and the Schiff bases. Whereas, the UV spectral data of the Schiff bases displayed the ???* (Phenyl ring) and n??* (C=N and –OH) transitions and the UV-Vis spectral results of the mixed Schiff base complexes  suggested the geometrical structure which is an octahedral geometry around the metal ions. The mass spectral fragmentations of the Schiff bases were studied and confirming the formation of the Schiff bases, also the mass spectral fragmentations of the Iron(III) mixed Schiff base complex was done. The electron paramagnetic resonance spectral results confirmed the data which are obtained from UV-Vis study.