Synthesis, Spectroscopic, Thermal, and In Vitro Anticancer Properties of Some M(II) Complexes of 3-(-1-(4,6-Dimethyl-2-pyrimidinylimino)methyl-2-naphthol

Abstract

Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) complexes of the Schiff base 3-(-1-(4,6-dimethyl-2-pyrimidinylimino)methyl-2-naphthol have been synthesized and characterized by infrared (IR), electronic, nuclear magnetic resonance (1H-NMR), and mass spectroscopies, elemental and thermal analyses, and room-temperature magnetic, powder x-ray diffraction, and conductance measurements. The involvement of the azomethine N and enol O atoms in bonding resulted in an N2O2 chromophore around the central metal atom. The room-temperature magnetic data, IR, and electronic spectral measurements are corroborative of a 4-coordinate square planar/tetrahedral geometry for the Ni(II), Cu(II), and Zn(II) complexes, and a 6-coordinate octahedral geometry for the Mn(II) and Co(II) complexes with water occupying the fifth and sixth coordination sites. All the complexes are high spin and nonelectrolyte in dimethylformamide (DMF). The metal complexes generally have mild to very good anticancer activity in vitro against HL 60 (leukemia) and 518A2 (melanoma) carcinomas, with IC50 in the range 7.67–20.67 μm, respectively. [CuL2] has the best cytotoxic activities against both HL60 (leukemia) and melanoma (518A2) carcinomas with IC50 of 7.67 and 11.20 μm, respectively, which is half as sensitive as and three times more sensitive than CDDP.