A Novel Mannich Based Metal II Complexes: Synthesis and Characterization of Magnetic, Conductivity and Antimicrobial Properties

Abstract

A novel Mannich base (2R,9R)-2-((S)-((2-aminoethyl)amino)(2-hydroxyphenyl)methyl)-6-hydroxy-9-phenyl-2,3,4,9-tetrahydro-1H-xanthen-1-one (LI), composed from xanthene, salicylaldehyde, and ethylenediamine, was employed to synthesize unique complexes of Ni(II), Mn(II), Cr(II), Co(II), and Cu(II). The structural characteristics of the complexes were determined by studying microanalytical findings and using analytical methods such as EPR, FT-IR, ¹H & ¹³C NMR, and UV-visible spectroscopy. The electronic spectra of the complexes suggested that the metal ion is fenced with octahedral structure. The molar conductivity of the metal chelates in DMSO was shown in the range of 18–28 Ω^–1mol^–1cm². The EPR studies of the copper complex dissolved in dimethyl sulfoxide (DMSO) was obtained at temperature of 300 K, and its unique characteristics were analysed. The antimicrobial potential of the ligand and its complexes has been thoroughly examined towards K. pneumaniae, S. aureus, P. aeruginosa, E. coli, C. albicans, C. neoformans, M. audouinii, A. niger microorganisms. Experimental results have demonstrated that all of the complexes exhibit substantial antimicrobial action when related to both the unbound ligand and the standard. Furthermore, the validity of the biological research was verified through molecular docking antifungal and antibacterial tests. Overall, the obtained results confirm the multidirectional antimicrobial efficacy of the new Mannich base complexes and demonstrate their high pharmaceutical potential for further studies.