Synthesis, spectral characterization, and biological evaluation of transition metal complexes of bidentate N, o donor schiff bases.

Sajjad Hussain Sumrra,Sabahat Ambreen,Muhammad Danish,Fouzia Sultana Rehmani,Muhammad Imran,Muhammad Ibrahim

doi:10.1155/2014/812924

Abstract

New series of three bidentate N, O donor type Schiff bases (L 1 )–(L 3 ) were prepared by using ethylene-1,2-diamine with 5-methyl furfural, 2-anisaldehyde, and 2-hydroxybenzaldehyde in an equimolar ratio. These ligands were further complexed with Co(II), Cu(II), Ni(II), and Zn(II) metals to produce their new metal complexes having an octahedral geometry. These compounds were characterized on the basis of their physical, spectral, and analytical data. Elemental analysis and spectral data of the uncomplexed ligands and their metal(II) complexes were found to be in good agreement with their structures, indicating high purity of all the compounds. All ligands and their metal complexes were screened for antimicrobial activity. The results of antimicrobial activity indicated that metal complexes have significantly higher activity than corresponding ligands. This higher activity might be due to chelation process which reduces the polarity of metal ion by coordinating with ligands.

Highlights

Schiff bases played an important role as ligands even a century after their discovery in coordination chemistry [1]
The Schiff bases and their metal chelates were screened for antibacterial activity against six bacterial strains: Escherichia coli, Streptococcus faecalis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, and Bacillus subtilis, and screened for antifungal activity against following six fungal strains: Trichophyton mentogrophytes, Epidermophyton floccosum, Aspergillus niger, Microsporum canis, Fusarium culmorum, and Trichophyton schoenleinii
Three bidentate N, O donor type Schiff bases were prepared by using ethylene-1,2-diamine with 5-methyl-2-furaldehyde, 2-anisaldehyde, and 2-hydroxybenzaldehyde in an equimolar ratio

Summary

Introduction

Schiff bases played an important role as ligands even a century after their discovery in coordination chemistry [1]. Schiff bases are derived from the condensation reaction of aromatic/aliphatic aldehydes and amines. They are an important class of organic ligands being extensively studied. Metal complexes having N, O donor atoms are very important because of their significant biological properties such as antibacterial [6, 7], antifungal [8], anticancer [9], and herbicidal [10] activity. In view of the significant structural and biological applications of ethylenediamine compounds, we wish to report the synthesis of a new class of Schiff bases (L1)–(L3), derived from the reaction of ethylene1,2-diamine with 5-methyl furfural, 2-anisaldehyde, and 2hydroxybenzaldehyde, respectively, and their Co(II), Cu(II), Ni(II), and Zn(II) metal complexes (1)–(12) (Scheme 2). The Schiff bases showed increased antibacterial activity against certain strains and their activities were enhanced on chelation (see Figures 1 and 2)

Methods

Results

Conclusion