Synthesis and crystal structures of manganese(III) complexes derived from bis-Schiff bases with antibacterial activity

摘要

Two mononuclear Mn(III) complexes, [MnL1(N-3)(OH2)] (1) and [(MnLL)-L-2 '] (2), where L-1 and L-2 are the dianionic forms of N,N '-bis(3-ethoxysalicylidene)-1,2-ethanediamine (H2L1) and N,N '-bis(3,5-dichlorosalicylidene)-1,4-butanediamine (H2L2), respectively, and L ' is the deprotonated form of 2,4-dichloro-6-(dimethoxymethyl)phenol (HL '), have been synthesized and characterized. The complexes were characterized by physico-chemical and spectroscopic methods. The Mn atoms in the structures are in octahedral coordination. In the crystal structure of complex (1), molecules are linked through intermolecular O-H center dot center dot center dot O hydrogen bonds to form dimers. In both complexes, there exist pi center dot center dot center dot pi interactions among molecules. The complexes and the Schiff bases were assayed for antibacterial activities by MTT method.