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

Abstract

The Schiff bases (L¹ and L²) and their complexes [Cu(L)₂] (L¹ = N-[(1)-1-(4-methylphenyl)ethylidene]benzolhydrazide and L² = N-[(1)-1-(2-methoxyphenyl)ethylidene]benzolhydrazide) have been prepared and characterized by elemental analysis, magnetic, and conductivity measurements. Crystal structure of the two complexes determined by single crystal X-ray analysis shows distorted square planar CuN₂O₂ coordination. Electron paramagnetic resonance spectra of these complexes in frozen DMSO show a signal at g ca 2. The trend in g-value (g _‖ > g _⊥ > 2.0023) suggests that the unpaired electron on copper(II) has character. The superoxide dismutase and biological (antimicrobial) activities of these complexes have also been screened.

Keywords:

• Copper(II) complexes
• Biological activities
• Superoxide dismutase activity
• Electron paramagnetic resonance

Acknowledgments

Our sincere thanks are due to the National Diffraction Facility, X-ray Division, and RSIC (SAIF), IIT Mumbai for single crystal data collection and EPR measurements, respectively. The Head RSIC (SAIF), Central Drug Research Institute, Lucknow is also thankfully acknowledged for providing analytical and spectral facilities. Financial assistance from UGC [Scheme no. 36-28/2008 (SR)] and DRDO [Scheme no. ERIP/Er/0603574/M/01/1118] Delhi are also thankfully acknowledged.