1564-1573This study is a complementary study to our previous study that included the synthesis and characterization of some
maleanilic acid derivative ligands (L1-4) and their metal carbonyl complexes (2-4)a-d as effective compounds for cancer cell
growth inhibition against three cancer cell lines: HCT-116, HepG-2 cells and MCF-7. The activity data has manifested that
the p-nitrophenyl maleanilic acid ligand (L2) and its chromium complex (2b) inhibited the tested cancer cells more
effectively than the other complexes. Additionally, DFT and TD-DFT studies are performed to investigate their frontier
molecular orbital (FMO), optical properties, and the correlation between the structure and biological activity. The calculated
optical energy gap (Eg) is in the range of 1.78- 2.13 eV, and electron cloud delocalization of HOMO/LUMO levels revealed
that all complexes show effective charge separation. The DFT results show a strong relation between Eg values of the
carbonyl complexes and their experimental biological activity, where it is obvious that complex (2b) with the lowest Eg
value has the greatest inhibitory potency against cancer cells. In contrast, complex (2d) with the highest Eg value exhibits
the lowest inhibition potency. These findings translate the inverse relationship between Eg values of the complexes and the
inhibition potency against cancer cells
