Role of extended conjugation on Electronic, Electrochemical, and antimicrobial properties of FeN4-Macrocyclic complexes

Abstract

Developing novel transition metal complexes with unique structures and properties has garnered significant attention in coordination chemistry. In this work, we prepared two Fe-macrocyclic complexes, A and B, with similar macrocyclic core but differing in the number of phenyl group substitutions via the template approach. The complexes were characterized using several analytical tools. The data were found to be in good agreement with the proposed structure of these complexes. Further electrochemical studies indicated a slight anodic shift in Fe(II) reduction, which can be attributed to the phenyl group effect. The theoretical investigations demonstrated that phenyl groups on the macrocyclic core of complex A significantly reduced the charge density on the Fe center due to extended conjugation, as compared to complex B, making the conversion of Fe(II) to Fe(I) easy. Additionally, the prepared complexes were studied for their antimicrobial activity against various pathogens, and it was found that complex A is more effective against E. coli compared to the standard drug Gentamycin.

Keywords

• Template reaction
• Schiff base
• Antimicrobial
• Redox
• Metal complexes