Spectral Characterization and Antimicrobial Activity of Some Schiff Bases Derived from 4-Chloro-2-aminophenol and Various Salicylaldehyde Derivatives

A series of N-（5-chloro-2-hydroxyphenyl）-（3/4/5-substituted）-salicylaldimines （I--XI） were synthesized using appropriate synthetic route. Their structures were characterized by FT-IR, UV-Visible, ESI-MS, 1H and 13C NMR spectroscopic techniques and analytical methods. The crystal structure of N-（5-chloro-2-hydroxyphenyl）-5-bromo- salicylaldimine （V） was determined by X-ray diffraction at room temperature. Relationship between the melting points and the structures of the compounds was examined. Antimicrobial activity of the compounds was evaluated against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis. Antifungal activities were reported for Candida albicans. Schiff bases showed considerable antimicrobial activity against S. aureus, S, epidermidis and C. albicans. N-（5-Chloro-2-hydroxyphenyl）-3-hydroxy-salieylaldimine （II） has the broadest and highest antimicrobial activity according to the others.