Synthesis, characterization, antibacterial activities and theoretical studies of Mn(II) and Cd(II) complexes with new macrocyclic Schiff base ligands incorporating a phenanthroline head unit

Three new hexaaza (N6) macrocyclic Schiff base ligands containing a phenanthroline moiety (L1-L3) have been synthesized and their coordination capability toward perchlorate salts of Mn(II) and Cd(II) have been investigated. The complexes are 18- and 19-membered hexaaza macrocycles, and incorporate a 1,10-phenanthroline unit as an integral part of their cyclic structure. All complexes have been characterized by a variety of methods such as IR, elemental analysis, EI-Mass, and conductivity measurements and in the case of cadmium complexes by H-1 and C-13 NMR spectroscopy. DFT (BP86) calculation on structures and molecular orbital of Mn(II) and Cd(II) complexes of latter ligands are also reported. Also the synthesized complexes were screened for their antibacterial activities against six bacterial strains and showed antibacterial effects.