Cyclometalated iridium (III) complexes (Ir1-Ir4) are calculated in detail with computational chemistry methods. The calculated structural parameters of Ir3 are compared with experimental values and a good fit is obtained. IR spectra are calculated at B3LYP/LANL2DZ/6-31G(d) level in the gases phase. Calculated H-1-NMR chemical shift values of the mentioned complexes are compared with the experimental data and all chemical shifts are assigned to the respective atoms. The quantum chemical parameters such as absolute hardness (eta), absolute softness (sigma) electronegativity (chi), chemical potential (mu) and electronic charges (Delta N-max) are calculated and are associated with the experimental anti-cancer properties of the related complexes. Nonlinear optic properties of the Ir1-Ir4 were investigated with the average linear polarizability (alpha), the anisotropy of the polarizability (Delta alpha), first hyperpolarizability (beta(0)) values. Hole transfer (t(h)), electron transfer integrals (t(e)), hole reorganization energies (lambda(h)) and electron reorganization energies (lambda(e)) are examined. In addition, molecular docking study was performed. It was found that the molecular docking results are similar to the experimental anti-cancer trend.