Synthesis, spectral, NLO studies, and antimicrobial activities of curcumin diketimine metal complexes

Abstract

A series of metal(II) complexes ML [where M = Cu(II), Co(II), Ni(II), Zn(II)] have been prepared from [4-((1H-indol-3-yl)methylene)-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,6-diene-3,5-dione] (IMHH) and 2,4-diamino-6-phenyl-1,3,5-triazine. The structures of the complexes have been investigated by using elemental analysis, magnetic susceptibility, molar conductance, IR, UV-Vis, mass, NMR, and ESR spectral studies. Conductivity measurements reveal that all the complexes are electrolytes. Spectral and other data show either octahedral or square-pyramidal geometry for all the complexes. Redox behavior of the copper(II) complex has been studied through cyclic voltammetry. Antimicrobial activities of the compounds were studied against several microorganisms with all the complexes having higher activity than free ligand. All the compounds may serve as potential photoactive materials as indicated from their fluorescence properties. The second harmonic conversion efficiency of the ligand has been found to be higher than that of urea and KDP.

Keywords:

• Curcumin
• Indole-3-aldehyde
• s-Triazine
• Metal(II) complexes
• Fluorescence
• SHG

Acknowledgments

The authors thank the Management of Thiagarajar College, Madurai and one of the authors (PT) thanks the Defence Research and Development Organization (DRDO), New Delhi for providing financial support and SAIF, IIT, Bombay and SAIF, CDRI, Lucknow for analytical facilities.