Synthesis, Spectroscopic and Antimicrobial Study of Transition Metal Complexes of 4-Hydroxy-3-Methoxybenzaldehyde and 2-Hydroxy 5-Nitrobenzaldehyde Semicarbazone

Abstract

Semicarbazones are compounds which are synthesized by condensation of semicarbazide hydrochloride and aldehydes or ketones. The literature survey revealed that semicarbazones had been emerged as a compound with broad range of activities including anticonvulsant, antitubercular, anticancer and antimicrobial activity. The aim of this study is to synthesis and characterization of 4-Hydroxy-3-methoxybenzaldehyde seimcarbazone Schiff base and its  Nickel (II), Cobalt (II) complexes and 2-Hydroxy-5-nitrobenzaldehyde seimcarbazone Schiff base and its Nickel (II) complex. The results of FT-IR and UV-Vis spectra of the Schiff bases and metal complexes confirm the formation of azomethine group (C=N) accompanied with the absence of carbonyl group and the formation of new (M-N) and (M-O) bonds with all metal ions. The results assign that 4-Hydroxy-3-methoxybenzaldehyde seimcarbazone is neutral and bidentate species witch coordinated via azomethine N and O with both metal ions and 2-Hydroxy-3-methoxybenzaldehyde seimcarbazone is neutral tridentate species witch coordinated via azomethine N, O and OH group. The antimicrobial activity of Schiff bases and their metal complexes was carried out against four types of bacteria (Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli) and one fungus (Candida ablicans) by using disc diffusion method. The results showed that the two Schiff bases were active against four tested organisms. The Nickel (II) complex of 4-Hydroxy-3-methoxybenzaldehyde seimcarbazone was active against one type of bacteria (Pseudomonas aeruginosa) and partially active against three type of bacteria (Escherichia coli, Staphylococcus aureus and Bacillus subtilis) and one fungus (Candida albicans) and Cobalt (II) complex of 4-Hydroxy-3-methoxybenzaldehyde seimcarbazone was partially active against one type of bacteria (Staphylococcus aureus) and one fungus (Candida albicans) and inactive against three type of bacteria (Escherichia coli, Pseudomonas aeruginos and Bacillus subtilis). And Nickel (II) complex of 2-Hydroxy5-  itrobenzaldehyde seimcarbazone was partially active against two type of bacteria (Escherichia coli, Pseudomonas aeruginos) and one fungus (Candida albicans) and inactive against two types of bacteria (Pseudomonas aeruginosa and Bacillus subtilis).