In our earlier report, we perceived that the frequency doubling behavior of imidazole-picrate hybrid crystals are high upon attaching electron withdrawing groups than electron donating one. Therefore, in order to enhance non-linear optical behavior of the imidazole-picrate hybrid crystals, we trialed with electron-withdrawing groups. Hence, In this report, the substitution of the electron-withdrawing -Cl (chlorine) or -OCH₃ (methoxy) group at the phenyl ring found to enhance the second harmonic generation-nonlinear optical (SHG-NLO) property of the imidazole-picrate hybrid crystals. The total dipole moment (μ_total), electronegativity and hyperpolarizability (β₀) of -Cl (compound 1) and -OCH₃ (compound 2) substituted hybrids were assessed through computations to estimate the SHG-NLO abilities. Although both groups (-Cl,-OCH₃) exhibit electrons withdrawing behavior, the higher values of μ_total, electronegativity, and β₀ values computed for -Cl substituted imidazole-picrate hybrid crystals are the indicative factor for the superior NLO behaviour of 1. The computed μ_total, electronegativity and β₀ of 1 and 2 infers that the substitution of strong electron withdrawing group; Cl in the phenyl ring of imidazole-picrate maximizes the uneven distribution of electrons than -OCH₃. The measured SHG of value for the single crystal of 1 is comparatively higher than 2. SHG of 1 is 1.75 (times that of KDP) and 2 is 1.20 (times that of KDP). In order to, confirm and demonstrate the relevant electronic and structural aspects of the crystals further experiments and computations were carried out and reported.