Characterization and antimicrobial activity of Erbium(III) complexes of C-3 substituted 2-hydroxy-1,4-naphthalenedione-1-oxime derivatives

Abstract

Erbium(III) complexes of 2-hydroxy-1,4-naphthalenedione-1-oxime and its C-3 substituted derivatives are synthesized and characterized by elemental analysis, thermogravimetric analysis, infrared spectroscopy, magnetic susceptibility measurements. 2-hydroxy-1,4-naphthalenedione-1-oxime derivatives are analyzed using 1H and 13C NMR spectroscopy. The molecular composition of the synthesized complexes is found to be [ML3(H2O)2]. The antimicrobial activity of these complexes is determined by well diffusion method against the target microorganisms- Staphylococcus aureus, Xanthomonas campestris, Pseudomonas aeruginosa, Candida albicans and Aspergillus niger. The antimicrobial activities of 2-hydroxy-1,4-naphthalenedione-1-oximes and their complexes are compared. It is observed that 2-hydroxy-1,4-naphthalenedione-1-oximes exhibit higher antifungal activity as compared to antibacterial activity. These activities are reduced upon complexation of these oximes with Erbium.