Synthesis, Characterization, Computational and Biological Activity of Some Schiff Bases and Their Fe, Cu and Zn Complexes

Four new symmetrical Schiff bases derived from 2,2 '-diamino-6,6 '-dibromo-4,4 '-dimethyl-1,1 '-biphenyl or 2,2 '-diamino-4,4 '-dimethyl-1,1 '-biphenyl, and 3,5-dichloro- or 5-nitro-salicylaldehyde, were synthesized and reacted with copper-, iron- and zinc-acetate, producing the corresponding complexes. The Schiff bases and their metal complexes were characterized by H-1-, C-13-NMR, IR and UV-Vis spectroscopy and elemental analysis. The structures of one Schiff base and the two zinc complexes were resolved by X-ray structure determination. Density functional theory (DFT) calculations at the B3LYP/6-31G(d) level of the latter compounds were carried out to optimize and examine their molecular geometries. The biomedical applications of the Schiff bases and their complexes were investigated as anticancer or antimicrobial agents.