Structural characterization of cobalt(II) complexes of an N,O donor Schiff base and their activity on carcinoma cells

Abstract

2-[{[2-(Dimethylamino)ethyl]imino}methyl]-6-methoxyphenol (LH) is a potential tetradentate monoanionic N2O2 chelator; however, this precursor coordinates to cobalt(II) centres in two ways, as neutral bidentate-NO and as terdentate-N2O, along with a pseudohalide, like thiocyanate and azide, to afford [Co(LH)2(NCS)]NO3 (1) and [Co(LH)2(N3)]NO3 (2), respectively. Both the complexes are characterized by spectroscopic (IR, UV–Vis) analysis, thermal and redox studies. The room temperature magnetic moments for 1 and 2 are 4.91 and 4.93B.M, respectively. Single crystal X-ray diffraction analysis confirms the distorted octahedral geometry around Co(II). These two complexes (1 and 2) inhibit the cell growth of human lung carcinoma cells (A549 cells), human colorectal carcinoma cells (COLO 205 cells), human hepatocellular carcinoma cells (PLC5 cells) and human fibroblasts cells (NIH3T3). Complex 2 shows a higher inhibitory activity, with 46.00±1.09μM IC50 in human colorectal carcinoma cells (COLO 205 cells).