Microwave assisted synthesis, characterization and bioactivity evaluation of a cobalt (II) complex with a novel Schiff base ligand derived from phenylacetyl urea and salicylaldehyde

Abstract

The study comprehensively focusses on the synthesis and characterization of a novel Co(II) metal complex formed by the condensation of phenylacetyl urea and salicylaldehyde with Thiocyanate ion using an eco-friendly microwave irradiation technique, which resulted in a higher yield. The molecular formula and geometry of the complex were deduced through an array of techniques including UV–Vis spectra, FT-IR, Far IR, Cyclic voltammetry, thermal analysis, and Powder XRD. The molar conductance data revealed a non-electrolyte [1:0] type complex. Notably, the FT – IR spectral peaks obtained at 3388 cm−1, 2914 cm−1,1622 cm−1 shows that Schiff base and Thiocyanate ions were coordinated to the metal ion in a monodentate manner. Furthermore, electronic spectra values confirmed a pseudo tetrahedral geometry for the complex. Intriguingly, our study also encompassed an exploration of the biological activities of both the Schiff base ligand and the Co(II) metal complex. By subjecting them to antimicrobial assays against various microorganisms, including Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeurginosa, Staphlococcus aureus, Bacillus cereus, Aspergillus favus, Aspergillus niger, Aspergillus sojae, Aspergillus oryzae, and Candida albicans. It was found that the complex exhibited moderate activity against bacteria and remarkably enhanced activity against fungi when compared to the free Schiff base ligand. Additionally, we investigated the DPPH free radical scavenging activity of the complex and the ligand, unveiling that the Co(II) complex demonstrated significantly higher antioxidant activity in comparison to the ligand. These results highlight the potential of the synthesized Co(II) complex as a promising candidate for biomedical applications. Overall, this study not only sheds light on the synthesis and characterization of the Co(II) metal complex with a novel Schiff base ligand but also unravels its distinct biological activities, indicating its potential significance in antimicrobial and antioxidant applications.