Synthesis and characterization of a novel Mn(III)-(γ-diketone) complex with catalytic and antifungal activity

Abstract

A novel Mn(III) complex with γ-diketone having general formula [Mn(hdo)₃], where hdo = hexane-2,5-dione ligand, has been synthesized and characterized using UV–vis, FT-IR, ESI-mass and EPR spectra, elemental analysis, powder X-ray diffraction, SEM, and magnetic susceptibility measurements. The X-ray diffraction studies reveal that it has monoclinic lattice system with C₂/C space group and the unit cell dimensions are a = 9.92245 Å, b = 10.50696 Å, and c = 9.80835 Å. The particle size of this complex has been found to be 32.1 nm. The complex was evaluated for its antifungal activity against Aspergillus flavus, Aspergillus niger, and Aspergillus terreus fungal species. The results indicate that the minimum inhibitory concentration of the synthesized complex was 8 ppm for A. niger while for A. flavus and A. terreus it was 6 ppm. β-Diketone Mn(III) complexes inhibit the fungal growth only partially. This communication is the first report of transformation of a keto-group to an ester group catalyzed by a metal complex.

Graphical Abstract

KEYWORDS:

• Mn(III) complex
• hexane-2,5-dione
• monoclinic system
• magnetic susceptibility
• SEM
• antifungal activity
• transformation

Acknowledgments

The authors acknowledge the Head, Department of Chemistry, DDU Gorakhpur University, Gorakhpur, for providing all necessary facilities for the work. We gratefully acknowledge CDRI Lucknow, IIT Kanpur and STIC Cochin for helping in different analytical analyses. The authors are also thankful to the Department of Botany, DDU Gorakhpur University, Gorakhpur, for providing facilities for antifungal studies.

Disclosure statement

No potential conflict of interest was reported by the authors.