Exploring superior nonlinear optical properties of copper complexes with π-conjugated ligands: experimental and theoretical investigation

esu, respectively. These findings underscore their significant optical nonlinearity and suitability for intensity-dependent NLO applications, as evidenced by their high values of negative refractive index. Density Functional Theory (DFT) investigations were performed at the M062X/(6-31G(d,p)/LanL2DZ)) level to evaluate key reactivity descriptors, including polarizability, hyperpolarizability, and dipole moment, which align with the experimental results. Conceptual DFT analysis reveals that complex 1 is more stable, while complex 2 exhibits higher reactivity. The strong hyperpolarizability and remarkable third-order NLO properties of these copper complexes demonstrate their potential for advanced photonic and optoelectronic applications.