Synthesis, characterization and crystal structures of nickel(II) complexes derived from Schiff bases with antimicrobial activity

Two new acetate-bridged trinuclear nickel(II) complexes, [Ni3(L1)2(NCS)2(CH3COO)2(CH3OH)2] (1), [Ni3(L2)2(NCS)2(CH3COO)2(CH3OH)(OH2)]& sdot;H2O (2), and two new azide-bridged dinuclear nickel(II) complexes, [Ni2(L1)2(mu 1,1-N3)(N3)(OH2)] (3), [Ni2(L2)2(mu 1,1-N3)(N3)(OH2)]& sdot;CH3OH (4), where L1 and L2 are the deprotonated form of 2-ethoxy-6-(((2-(pyrrolidin-1-yl)ethyl)imino)methyl)phenol (HL1) and 2-methoxy-6-(((2-(pyrrolidin-1-yl)ethyl)imino)methyl)phenol (HL2), respectively, were prepared and characterized by elemental analysis, IR and UV-vis spectra. Their structures were determined by single crystal X-ray diffraction. The Ni atoms are in octahedral coordination. The compounds were evaluated against the bacteria Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas fluorescence, and the fungi Candida albicans and Aspergillus niger.