Structural, spectroscopic, and biological studies of N,O donor Schiff base copper(II) complexes

Synthesis, Characterization and Antimicrobial Activities of Copper Derivatives of NHC-II Complexes

BACKGROUND

Caffeine, 1, 3, 7-trimethylxanthine is one of the xanthine derivatives that are for the most part utilized as a part of solutions as diuretics. The Cu (II) complexes have been synthesized from the N-heterocyclic carbene ligands.

MATERIALS AND METHODS

The Cu (II) NHC complexes were characterized using analytical and spectral techniques. Antibacterial and antifungal activities of the Cu (II) NHC complexes were determined using the reported techniques. The SOD activity was assayed using nitrobluetetrazolium as O2 scavenger.

RESULTS

The X-band ESR spectra of the copper complexes in DMSO solution at 300 and 77 K were recorded and their salient features are reported. The in vitro biological screening effects of the investigated compounds were tested against the bacterial species, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris and Pseudomonas aeruginosa and fungal species, Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola and Candida albicans by serial dilution method.

CONCLUSION

The Cu (II) complexes exhibit square planar geometry. A comparative study of inhibition values of the individual metals and their complexes indicate that the complexes exhibit higher antimicrobial activity than the individual metals. Superoxide dismutase and reducing power activities of the copper complexes have also been studied. Depending on the molecular structure, the Cu (II) NHC complex possess promising SOD mimetic activities. Further we are trying to explore more biological properties of Cu (II) NHC complexes in vitro and in vivo.

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

Azo Schiff base complexes of VO(II), Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) have been synthesized from 4-((4-chlorophenyl)diazenyl)-2-((p-tolylimino)methyl)phenol (CDTMP). The nature of bonding and the structural features of the complexes have been deduced from elemental analysis, molar conductance, magnetic susceptibility measurements, IR, UV-Vis,1H-NMR, EPR, mass, SEM, and fluorescence spectral studies. Spectroscopic and other analytical studies reveal square-planar geometry for copper, square-pyramidal geometry for oxovanadium, and octahedral geometry for other complexes. The 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. The 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 fluorescence properties. The 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.