Two complexes (C6H9N2)2[CuCl4] (1) and (C5H6N2Cl)2[CuCl4] (2) have been synthesized and characterized by single‐crystal X‐ray diffraction which revealed that these phases are centrosymmetric and crystallize, respectively, in monoclinic and triclinic symmetries. The thermal properties of both complexes are investigated as well as the UV‐Vis spectroscopic, photoluminescence properties, electronic paramagnetic resonance and biological activities. The crystal packing of the two compounds is guided by N−H⋅⋅⋅Cl hydrogen bonds and offset π–π stacking interactions; these interactions contribute to the overall stabilization of the structures as they connect anions and cations together into a three‐dimensional network. In addition, the optimized molecular structure was calculated by the Density Functional Theory (DFT) method using the B3LYP function with the LanL2DZ basis set. Subsequently, the thermal behavior was studied by TGA/DTA analyses. Moreover, the optical properties were studied using optical absorption UV‐visible and photoluminescence (PL) spectroscopy. The analysis of the magnetic properties is studied by electronic paramagnetic resonance (EPR). Simultaneously, compound (1) exhibits a potential inhibitory effect against the key enzymes associated with diabetes, obesity, and hyperlipidemia. It demonstrates IC50 values of 0.21 μM and 0.32 μM against α‐amylase and lipase, respectively. Consequently, it emerges as a promising candidate for the treatment of diabetes and obesity.