Synthesis, Spectroscopic Characterization, and Biological Activities of Metal Complexes of 4-((4-Chlorophenyl)diazenyl)-2-((p-tolylimino)methyl)phenol

Hindawi Publishing Corporation Journal of Chemistry Volume 2013, Article ID 724163, 12 pages http://dx.doi.org/10.1155/2013/724163 Research Article Synthesis, Spectroscopic Characterization, and Biological Activities of Metal Complexes of 4-((4-Chlorophenyl)diazenyl)-2-((p-tolylimino)methyl)phenol C. Anitha,1 C. D. Sheela,2 P. Tharmaraj,3 and V. V. Hema2 1 Department of Chemistry, Fatima Michael College of Engineering & Technology, Madurai 625 020, India Department of Chemistry, e American College, Tamilnadu, Madurai 625 002, India 3 Department of Chemistry, iagarajar College, Tamilnadu, Madurai 625 009, India 2 Correspondence should be addressed to P. armaraj; Received 10 June 2012; Accepted 20 August 2012 Academic Editor: Ai-Min Ren Copyright © 2013 C. Anitha et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Azo Schiff base complexes of VO(II), Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) have been synthesized from 4-((4chlorophenyl)diazenyl)-2-((p-tolylimino)methyl)phenol (CDTMP). e nature of bonding and the structural features of the complexes have been deduced from elemental analysis, molar conductance, magnetic susceptibility measurements, IR, UV-Vis, 1 H-NMR, EPR, mass, SEM, and �uorescence spectral studies. Spectroscopic and other analytical studies reveal square-planar geometry for copper, square-pyramidal geometry for oxovanadium, and octahedral geometry for other complexes. e EPR spectra of copper(II) complex in DMSO at 300 K and 77 K were recorded, and its salient features are reported. Antimicrobial studies against several microorganisms indicate that the complexes are more potent bactericides and fungicides than the ligand. e electrochemical behavior of the copper(II) complex was studied by cyclic voltammetry. All the synthesized compounds can serve as potential photoactive materials as indicated from their characteristic �uorescence properties. e second harmonic conversion efficiency of the synthesized azo Schiff base was found to be higher than that of urea and KDP (potassium dihydrogen phosphate). SEM image of copper(II) complex implies the crystalline state and surface morphology of the complex. 1. Introduction Azo compounds are the largest class of industrially synthesized organic dyes due to their versatile application in various �elds, such as dyeing textile �ber, biomedical studies, and advanced application in organic synthesis and high technology areas such as laser, liquid crystalline displays, and electrooptical devices [1]. e oxidation-reduction behaviors of these compounds play an important role in its biological activity [2, 3]. e architectural beauty of these coordination complexes arises due to the interesting ligand systems containing different donor sites [4]. Azomethine derivatives are widely applied in biological systems and dyes [5]. In recent years, there is considerable interest in the synthesis and modeling of new organic materials with optical nonlinearities because of their potential use in development of photonic devices [6]. Azo ligands containing salicylaldimine-based side chains can be used in the production of chemical sensors because they show a signi�cant change of color of the solution and maxima of the absorption band when they interact with transition metal atoms. Transition metal-complexed azomethine compounds have been studied in great detail in the literature for understanding their optical and electronic properties, structure-redox relationships, and mesogenic characteristics [7, 8]. It could be expected that design and synthesis of transition metal complexes derived from azo Schiff base ligands might be a possible way to obtain the applicable nonlinear optical materials [9]. In particular p-nitroaniline, m-nitroaniline, p-nitro-N,N-dimethylaniline, and other similar choromophores were found to exhibit rather large NLO properties [10]. Although many Schiff bases derived from aromatic aldehydes and amines and their corresponding metal complexes have been extensively studied, relatively few 2 Journal of Chemistry azo-linked Schiff bases and their metal complexes have been reported [11, 12]. 1.1. Scope. Design and synthesis of transition metal complexes derived from azo Schiff base ligands might be a possible way to obtain the applicable nonlinear optical materials, endowed with antiviral activity, optical activity, electronic activity, and so forth. e electron-pull and electron-push substituents on the benzene rings have much in�uence on the electronic structure of azo compounds to possess a larger nonlinear optical susceptibility. Because of the importance of azo-containing compounds and our interest in syntheses of nonlinear optical materials, we report herein the syntheses, spectroscopic studies and biological activities of azo Schiff base derivative 4-((4-chlorophenyl)diazenyl)-2((p-tolylimino)methyl)phenol (CDTMP) which have donor and acceptor property due to electron-pull and electron-push substituents (Cl and CH3 groups) and their VO(II), Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) complexes. We are also interested to examine the antimicrobial, �uorescence, NLO, and redox properties of these azo Schiff base compounds. 2. Experimental e chemicals and solvents were puri�ed by standard methods. Elemental analyses were carried out using a PerkinElmer 2400 II elemental analyzer. Molar conductance of the complexes was measured in DMSO at room temperature using a Systronic Conductivity Bridge 304. Magnetic susceptibility of the complexes was performed on a Sherwood MSB mark 1 Gouy balance. Infrared spectral studies were carried out on a Shimadzu FT IR 8000 spectrophotometer using KBr discs. UV-Vis spectra were obtained using a ermo Spectronic 6 Hexios 𝛼𝛼, and �uorescence spectra were determined with an Elico SL174 Spectro�uorometer. NMR spectra were recorded on Bruker DRX-300, 300 MHz NMR Spectrometer using TMS as reference. EPR spectra of the Cu(II) and VO(II) complexes were recorded in Varian E112 machine at 300 and 77 K using TCNE (Tetracyanoethylene) as the g-marker. Cyclic voltammetric measurements for Cu(II) and VO(II) complexes in DMSO were carried out on Electrochemical Analyzer CH Instruments (USA) using a three-electrode cell containing an Ag/AgCl reference electrode, Pt wire auxiliary electrode, and glassy carbonworking electrode with tetrabutylammonium perchlorate as supporting electrolyte. Electron-ionization (EI) mass spectra were recorded by JEOL-GC Mass Spectrometer MATE-2. 2.1. Synthesis of Azo Ligand (CDTMP). e diazonium salt, 5-((4-chlorophenyl)diazenyl)-2-hydroxybenzaldehyde (CPDAZ HB) [13] (2.3 g, 8.7 mmol), was condensed with p-toluidine (0.94 g, 8.7 mmol) in ethanol and re�uxed for 3 h. Aer the reaction was over, the reaction mixture was concentrated to one-half of the volume and refrigerated for one day. e obtaine (...truncated)