Cobalt(II) and Manganese(II) Complexes of Novel Schiff Bases, Synthesis, Charcterization, and Thermal, Antimicrobial, Electronic, and Catalytic Features

Selma Bal,Sedat Salih Bal

doi:10.1155/2014/506851

Abstract

Carbazoles containing two new Schiff bases (Z,Z)-N,N′-bis[(9-ethyl-9H-carbazole-3-yl)methylene]propane-1,3 diamine (L1) and (Z,Z)-N,N′-bis[(9-ethyl-9H-carbazole-3-yl)methylene]-2,2-dimethylpropane-1,3-diamine (L2) and their Co(II) and Mn(II) complexes were synthesized and characterized using various spectroscopic methods and thermal analysis, which gave high thermal stability results for the ligands and their cobalt complexes. The title compounds were examined for their antimicrobial and antifungal activities, which resulted in high activity values for the ligands and their manganese complexes. Oxidation reactions carried out on styrene and cyclohexene revealed that the complex compounds were the most effective catalysts for styrene oxidation, giving good selectivities than those of cyclohexene oxidation. Electronic features of the synthesized compounds were also reported within this work.

Highlights

Schiff bases and their complexes have been and are being employed to many reactions in synthetic chemistry
Various Schiff base complexes have been employed to catalytic oxidation of olefins to epoxides and aldehydes, and it has been proved that many Schiff base complexes gave improved results as catalysts for these kinds of oxidation reactions [7,8,9,10,11,12,13,14,15,16,17,18,19,20]
All the synthesized compounds were effective for almost all of the microorganisms; in particular, for the microorganisms K. pneumoniae, E. aerogenes, S. faecalis, and S. aureus the title ligands brought about bigger inhibition zones

Summary

Introduction

Schiff bases and their complexes have been and are being employed to many reactions in synthetic chemistry. The synthesized Schiff base complexes have been searched for their potential use as catalysts in oxidation reactions for both cyclohexene and styrene. It is important that the catalysts are thermally stable enough to carry out these kinds of reactions which generally require elevated temperatures [21, 22] In addition their catalytic activities, various Schiff bases have been examined for their biological activities in many previous studies [23,24,25]. In previous studies various carbazoles containing Schiff bases and their coordination compounds have been synthesized, characterized, and examined for their different features such as luminescence, thermal property [29,30,31,32,33], biological activity [34], and electrochemical and optical behaviour [35,36,37] and for their use as Langmuir-Blodgett film [38]. Advances in Chemistry thermal, electrochemical, antimicrobial features, and their effect as catalysts in the oxidation reactions of cyclohexene and styrene

Experiment

Results and Discussion

Conclusion