Doubly end-on azido bridged mixed-valence cobalt trinuclear complex: spectral study, VTM, inhibitory effect and antimycobacterial activity on human carcinoma and tuberculosis cells

Abstract Doubly end-on azido-bridged mixed-valence trinuclear cobalt complex, [Co 3 (L) 2 (N 3 ) 6 (CH 3 OH) 2 ] ( 1 ) is afforded by employing a potential monoanionic tetradentate-N 2 O 2 Schiff base precursor (2-[{[2-(dimethylamino)ethyl]imino}methyl]-6-methoxyphenol; HL). Single crystal X-ray structure reveals that in 1 , the adjacent Co II and Co III ions are linked by double end-on azido bridges and thus the full molecule is generated by the site symmetry of a crystallographic twofold rotation axis. Complex 1 is subjected on different spectral analysis such as IR, UV–vis, emission and EPR spectroscopy. On variable temperature magnetic study, we observe that during cooling, the χ M T values decrease smoothly until 15 K and then reaches to the value 1.56 cm 3  K mol −1 at 2 K. Complex 1 inhibits the cell growth on human lung carcinoma (A549 cells), human colorectal (COLO 205 and HT-29 cells), and human heptacellular (PLC5 cells) carcinoma cells. Complex 1 exhibits anti-mycobacterial activity and considerable efficacy on Mycobacterium tuberculosis H37Rv ATCC 27294 and H37Ra ATCC 25177 strains.