Iron(III)5(2′-hydroxyphenyl)-3-(4-X-phenyl)pyrazolinates and their addition complexes with N, P donor ligands: synthesis, spectral and antimicrobial investigations

Abstract

Iron(III)5(2′-hydroxyphenyl)-3-(4-X-phenyl)pyrazolinates of the type (C₁₅H₁₂N₂OX)₃Fe [where X =–H,–Cl,–CH₃,–OCH₃] have been synthesized by reaction of anhydrous FeCl₃ with the sodium salts of pyrazoline in 1 : 3 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. These newly synthesized derivatives have been characterized using elemental analysis (C, H, N and Fe), molecular weight measurement, magnetic moment data, FAB mass, ³¹P NMR and Mössbauer spectral data. The complexes have been examined for crystalline/amorphous nature through XRD; all complexes are amorphous. Octahedral geometry around iron(III) confirms the presence of three bidentate pyrazoline ligands in iron(III)5(2′-hydroxyphenyl)-3-(4-X-phenyl)pyrazolinates. In addition complexes pyrazoline is monodentate. The bidentate and monodentate behavior of pyrazoline ligands was confirmed by IR spectral data. All the complexes were tested for their in-vitro antimicrobial activity. The metal complexes and their adducts exhibit better antibacterial and antifungal activity than the pyrazolines.

Keywords:

• Pyrazoline
• 2,2′-Bipyridine
• 1,10-Phenanthroline
• Triphenylphosphine
• Antimicrobial activity
• Iron(III)pyrazolinates

Acknowledgements

The authors are thankful to RSIC, CDRI, Lucknow (India), A.P.S. University, Rewa (India), SAIF, IIT, Bombay, Mumbai (India), SIF, IISC, Bangalore (India), Mahakal Institute of Pharmaceutical Studies, Ujjain (India) and Inter University Consortium for the Department of Atomic Energy Facilities (DAEF), Indore (India) for providing spectral and analytical data.