Synthesis, Spectral, Magnetic and In-Vitro Anticancer Properties of Some Metal (II) Complexes of 3-[2,4-dihydro-1H-inden-4-ylimino) methyl] napthalene-2-ol

Novel Cu(II), Zn(II) and Pd(II) complexes of the Schiff base, 3-[2,4-dihydro-1H-inden-4-ylimino)methyl]napthalen-2-ol, have been prepared and characterized by elemental analysis, 1HNMR, molar conductance, room temperature magnetic moments, infrared and electronic spectral measurements. The purity of the ligands and the metal complexes are confirmed by microanalyses and 1HNMR. The IR spectra shows that the Pd(II) exhibits geometric isomerism, being in the trans isomeric form, and the ligand is bidentate coordinating via the azomethine N and naphthalene O atoms. The Cu (II) and Pd (II) complexes assume a four-coordinate square planar geometry; while the Zn (II) complex is tetrahedral, as indicated by room temperature moment and electronic spectra measurements. The complexes are non-electrolytes in nitromethane. The in-vitro anticancer activities of the Schiff base and its Cu(II), Zn(II) and Pd(II) complexes against HT-29 (colon) carcinoma and MCF-7 (human breast) adenocarcinoma are evaluated. The results show that the HT-29 cells are generally more sensitive than the MCF-7 cells to the metal complexes; and the Zn (II) complex has the best broad-spectrum anticancer activity against both colon and breast carcinomas, with IC50 values of 20.15 and 22.50 µM respectively. The activity of the Zn (II) complex against colon carcinoma is about a third of Cis-platin activity in the same assay.