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I. E. Otuokere ¹, E. N. Orjiako ², G. U. Okafor ³, A. J. Chinweuba ²

Affiliations
1 Department of Chemistry, Michael Okpara University of Agriculture, Umudike, NG
2 Department of Industrial Chemistry, Anambra State University, Uli, NG
3 Department of Pure and Industrial Chemistry, Nnanmdi Azikiwe University, Awka, NG

Abstract

New Schiff base ligand (benzene-1,2-diyldimethaniminedibenzoic acid) was prepared via condensation of o-phthaldehyde and 2-aminobenzoic acid in 1:2 ratio. Metal complexes were prepared and characterized using elemental analyses, IR, molar conductance, electronic spectra, ¹H NMR and ¹³CNMR. From the elemental analyses and spectra data, the complexes were proposed to have the general formulae [M(L₂)] (where M=Co(II), Ni(II), Cu(II) and Zn(II)). The molar conductance data revealed that all the metal chelates were non-electrolytes. IR spectra suggested coordination to the metal ions in a bi-negative tetradentate manner with NOON donor sites of the azomethine-N and carboxylate-O. The ¹H NMR spectral data indicate that the two carboxylate protons are also displaced during complexation. Formula determination using method of continuous variation gave metal:ligand ratio of 1:1. Based on spectra studies, a tetrahedral geometry have been proposed for the complexes.

Keywords

Schiff Base, Transition Metal Complexes, Spectroscopy, Molar Conductance.

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I. E. Otuokere ¹, E. N. Orjiako ², G. U. Okafor ³, A. J. Chinweuba ²

Affiliations
1 Department of Chemistry, Michael Okpara University of Agriculture, Umudike, NG
2 Department of Industrial Chemistry, Anambra State University, Uli, NG
3 Department of Pure and Industrial Chemistry, Nnamdi Azikiwe University, Awka, NG

Abstract

The reaction of benzene-1,3-diol with ethyl cyanide have been studied and the product 1-(2,4- dihydroxyphenyl) ethanone have been isolated. Divalent metal complexes of Co (II), Ni (II), Zn (II) and Pd (II) have been synthesized and tentative structures were proposed for these complexes based on elemental analysis, electrical conductivity, UV-Vis, IR, ¹HNMR, ¹³CNMR. The spectra studies suggested bidentate co-ordination through the carbonyl and deprotonated hydroxyl group. The formula determination by method of continuous variation suggested a metal:ligand ratio of 1:2. A tetrahedral geometry has been suggested for the complexes.

Keywords

Ligands, Complexes, Spectra, Tetrahedral Geometry.

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