Synthesis, Crystal Structures, Thermal and Antimicrobial Properties of Mn(II) Complexes of 1,10-Phenanthroline With Some Co-Ligands

The complexes of Manganese(II) with 1,10-phenanthroline using the nitrate, azide and dicyanamide as co-ligands have been synthesized and characterized by elemental analysis, infrared spectroscopy, thermal analysis and room temperature magnetic susceptibility measurements. The magnetic moments of the complexes are consistent with high spin (d5) octahedral geometry. Single-crystal X-ray analysis confirmed the complexes to be [Mn(Phen)2(NO3)2] (1), [Mn(Phen)2(N3)2)] (2), and [Mn(Phen)2(dca)2)] (3). Complexes 1 and 2 crystallize in an orthorhombic crystal system with space group Pbcn while complex 3 crystallizes in the monoclinic crystal system with space group P21/c. The complexes have been screened for in vitro antibacterial and antifungal activities by the disc diffusion method. The minimum inhibitory concentration values indicate that the complexes showed greater activity against the fungi strains tested compared to that of the reference antifungal.