Trivalent Cobalt Complexes with NNS Tridentate Thiosemicarbazones: Preparation, Structural Study and Investigation of Antibacterial Activity and Cytotoxicity against Human Breast Cancer Cells

New complexes of trivalent cobalt with substituted thiosemicarbazone ligands having an NNS donor system {HL1 = 4-(4-nitrophenyl)-1-((pyridin-2-yl)methylene)thiosemicarbazide and HL2 4-(2,5-dimethoxyphenyl)-1-((pyridin-2-yl)methylene)thiosemicarbazide} were synthesized via the in situ oxidation divalent chloride accompanying its addition to ligands. The C1 C2 characterized elemental (CHNS) analysis 1H NMR, FT-IR UV-Vis. spectroscopic data. Further, conductometric studies on DMF solutions indicated their 1:1 nature, diamagnetism revealed low-spin state complexes. X-ray diffraction complex that it crystallizes triclinic space group P-1. metal exhibits octahedral environment built by two anionic bound pyridine nitrogen, imine nitrogen thiol sulfur atoms. is counterbalanced a ion. In addition, lattice water molecules detected asymmetric unit cell. ligand (20 mg/mL DMSO) displayed inhibition zones 10 mm against both S. aureus E. coli, same concentration respective raised this activity 15 12 these bacterial strains, respectively. As comparison, ampicillin inhibited strains 21 25 mm, Screening assay HL1 four human cancer cells most enhanced breast MCF-7 cells. induced growth inhibitions all compounds (0–100 μg/mL) have been detected. HL2} gave IC50 values 52.4, 145.4 49.9 μM, These results are more meaningful comparison similar complexes, but less efficient compared 9.66 μM afforded doxorubicin. doxorubicin, cytotoxicity towards healthy BHK 36.42, 54.8 110.6 surviving fractions 66.1% 62.7% corresponding 100 μg/mL (136.8 131.4 C2).