No abstract

Azo compounds were prepared by the reaction between benzenediazonium chloride and 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid monosodium salt under alkaline conditions. Two new azo-linked Schiff base ligands, 4-(3-methoxysalicylidene)-5-hydroxy-6-(2-hydroxyphenylazo)-2,7-naphthalene disulfonic acid disodium salt (H 2 L) and 4-(3-methoxysalicylidene)-5-hydroxy-6-(2-hydroxy-4-cholorophenylazo)-2,7-naphthalenedisulfonic acid disodium salt (H 2 L 1 ), have been synthesized. Also, the new Cu II , Ni II and Co II complexes of the azo-linked Schiff base ligands were prepared and characterized by infrared spectra, UV-Vis, 1 H-and 13 C-n.m.r., attached proton test (APT) and distortionless enhancement by polarization transfer (DEPT) and atomic absorption spectroscopy, mass spectrocopy, elemental analyses, thermogravimetric analysis, conductivity and magnetic measurements. It was determined that the synthesized ligands were comprised of six-membered rings due to intramolecular hydrogen bonding. The results suggested that condensation of the azo-derivative compounds and o-vanillin in a 1:1 molar ratio produces mononuclear Schiff base ligands with an ONO donor set. Preliminary histological studies were made. Magnetic moment studies showed that all complexes have a tetrahedral configuration.

New Schiff bases have been synthesised by the condensation of 4-amino-5-hydroxynaphthalene-2,7-disulfonic acid mono sodium salt with ovanillin (H 2 L 1 ) and salicylaldehyde (H 2 L 2 ), and their complexes with copper(II), cobalt(II) and nickel(II) have been prepared. All compounds were characterized by elemental analyses, FT-IR, electronic spectral data, magnetic moments, mass spectroscopy and molar conductance. The 13 C NMR and 1 H NMR spectra of the Schiff base ligands have been recorded.The results suggested that the Schiff bases are coordinated to the metal ions through the phenolic oxygens and azomethine nitrogen to give mononuclear complexes. Magnetic measurements and absorption spectral data reveals that the copper and nickel complexes have tetrahedral geometry. All compounds were found to be non-electrolytes in aqueous solutions. According to mass spectroscopy and thermogravimetric data, all complexes have one water molecule coordinated to the metal ion.