Synthesis, spectral and biological investigations of 5(2′-hydroxyphenyl)-3-(4-substituted-phenyl) pyrazolinates of cobalt(II) and their addition complexes with N, P donor ligands

Abstract

5(2′-Hydroxyphenyl)-3-(4-substituted-phenyl)pyrazolinates of cobalt(II) of the type (C₁₅H₁₂N₂OX)₂Co [here substituted group X is–H,–Cl,–CH₃ or–OCH₃] have been synthesized by reaction of anhydrous cobalt(II)chloride with the sodium salt of the pyrazolines in 1 : 2 molar ratio. Their addition complexes with N and P donor ligands [2, 2′-bipyridine, 1, 10-phenanthroline and triphenylphosphine] were prepared in 1 : 1 molar ratio. The newly synthesized complexes were characterized by elemental analyses, molecular weight measurement, magnetic susceptibility, IR, electronic, ³¹P NMR and FAB mass spectra. All complexes are amorphous as determined by XRD. Tetrahedral geometry around cobalt(II) has been suggested, confirming the presence of two pyrazoline bidentate ligands, cobalt(II)5- (2′-hydroxyphenyl)-3-(4-substituted-phenyl)pyrazolinates. Upon ligand addition, pyrazoline changes to monodentate. The bidentate and monodentate behavior of pyrazoline ligands was confirmed by IR spectral data. The metal complexes and their adducts exhibit good antibacterial and antifungal activity, better than the pyrazolines.

Keywords:

• Pyrazoline
• 2,2′-Bipyridine
• 1,10-Phenanthroline
• Triphenylphosphine
• Biological investigation
• Cobalt(II)pyrazolinates

Acknowledgements

We are thankful to RSIC, CDRI, Lucknow (India), A.P.S. University, Rewa (India), SAIF, IIT Bombay, Mumbai (India), SIF, IISC, Bangalore (India) and Mahakal Institute of Pharmaceutical Studies, Ujjain (India) for providing spectral and analytical data.