Synthesis, structures, and antibacterial activity of Schiff-base cobalt(III) complexes

Two new Schiff-base cobalt(III) complexes, [CoL1(En)N3]Cl (I) and [CoL2N3(OH2)] (II), where L1, L2, and En are 2-[1-(2-aminoethylimino)ethyl]phenolate, bis(5-chlorosalicylidene)ethane-1,2-diamine, and 1,2-ethylenediamine, respectively, have been prepared and characterized by physicochemical methods and single crystal X-ray determination. Complex I crystallizes in monoclinic system space group P21/n with a = 7.113(1), b = 21.385(1), c = 10.599(1) Å, β = 106.067(2)°, V = 1549.2(3) Å3, Z = 4, R1 = 0.0322, and wR2 = 0.0800. Complex II crystallizes in monoclinic system space group P21/c with a = 1.679(1), b = 11.145(1), c = 12.493(1) Å, β = 110.553(2)°, V = 1783.5(2) Å3, Z = 4, R1 = 0.0360, and wR2 = 0.0838. Single crystal X-ray diffraction analysis reveals that the Co atoms in the complexes are six-coordinated in octahedral geometry. The complexes were screened in vitro for their antibacterial activity against Bacillus subtillis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa.