Microwave Preparation and Spectroscopic Investigation of Binuclear Schiff Base Metal Complexes Derived from 2,6-Diaminopyridine with Salicylaldehyde

Hasan A Mohammed,Nihad Ismeal Taha

doi:10.4236/ijoc.2017.74033

Hasan A Mohammed, Nihad Ismeal Taha

Open Access

https://doi.org/10.4236/ijoc.2017.74033

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Abstract

The binuclear Schiff base complexes prepared by condensation 2,6-diamino-pyridine and salicylaldehyde (LH) by using microwave and adding metal salts to ligand by same ratio. The Schiff base ligand was checked by infrared, electronic spectra and 1HNMR spectroscopy and prepared complexes characterized by molar conductivity, infrared, electronic spectra and susceptibility measurements. The values of molar conductivities reveal that the complexes are non-electrolytes, from obtained data of electronic spectra and magnetic moment, an octahedral geometry was suggested, coordinated to the metal ions in a manner with N donor sites of imine groups, and oxygen of phenolic OH group.

Highlights

The reactions of aldehyde or ketone with primarily amine in which carbonyl group is replaced by imine group is called Schiff bases, are widely used in organic synthesis [1]
The Schiff base ligand was checked by infrared, electronic spectra and 1HNMR spectroscopy and prepared complexes characterized by molar conductivity, infrared, electronic spectra and susceptibility measurements
The ligand was prepared by condensation of primary amine and aldehyde under microwave irradiated the complexes were prepared by direct addition of the ethanoic solution of the metals salts (Scheme 1)

Summary

Introduction

The reactions of aldehyde or ketone with primarily amine in which carbonyl group is replaced by imine group is called Schiff bases, are widely used in organic synthesis [1]. Salicylaldehyde is an important precursor to a variety of chelating agents [5]. Schiff bases of salicylaldehyde are well known as the polydentate ligands, coordinating as a deprotonated or neutral forms. I. Taha used as a ligand in coordination chemistry because its donor ability that deals with Schiff bases and their metal complexes due to synthetic flexibility and sensitivity toward a variety of metal atom and there are many studies [6] which prove this situation [7] [8]. Microwave is one of the modern green synthetic methodologies for Schiff bases [10] [11]. We prepare ligand (LH) (2,2'-((1E,1'E)-(pyridine-2,6-diylbis(azanylylidene)) bis (methanylylidene))diphenol) resulting from the condensation of salicylaldehyde with primary amines 2,6-diaminopyridine with some binuclear transition metals that the general formula [M2(LH)2Cl4]

Materials and Methods

Results and Discussion

Infra-Red Spectroscopy

Electronic Spectra

Magnetic Properties

Conclusion