Synthesis, Structural Characterization and Antitumor Activities of Manganese and Cobalt Isothiocyanate Complexes with 2,2’-Bipyridine

[Mn(SCN)(2)(2,2 '-bipy)(2)] (1) and [Co(SCN)(2)(2,2 '-bipy)(2)] (2) were synthesized at ambient temperature by adding aqueous solutions of manganese(II) or cobalt(II) chloride hydrate to aqueous acetonitrile solutions of 2,2 '-bipyridine (2,2 '-bipy) and potassium thiocyanate. Elemental analyses, FT-IR and UV-vis spectra were used to characterize 1 and 2. Single crystal X-ray diffraction was used to analyze the crystal structures of 1 and 2, revealing that the two are structurally similar. The molecular structures of 1 and 2 consist of Mn or Co ion chelated by two molecules of 2,2 '-bipy through four nitrogen atoms and two NCS anions, giving distorted octahedral geometries. The isothiocyanate group is not bridging, instead, two ligands coordinate in a cis arrangement to the manganese or cobalt center by their nitrogen atoms while the sulfur atoms are free. Through hydrogen bonding and pi-pi stacking interactions, the discrete units of 1 and 2 extend to 3D supramolecular networks with flower and fishbone-like structures. The luminescence behavior of 2,2 '-bipy, 1 and 2 were investigated. On HepG2 (liver) and MCF-7 (breast) cancer cells, the anticancer effects of 1 and 2 were evaluated. The activity of 1 and 2 on MCF-7 is more significant than that of HepG2. The IC50 of 1 was lower in HepG2 and MCF-7 cells than for 2.