An effective methodology for the quantitative preparation of copper (II) complexes from benzaldehyde-[N-(3-Hydroxy-2-Naphthoyl)] Hydrazone (H2L) in existence of SiO2 as a catalyst which reduced reaction time and produced high yield was discussed. The formed complexes were elucidated by applying spectral, analytical and conformational methods. The octahedral configuration was proposed for Cu (II) complexes based on magnetic moments, electronic spectral and electron spin resonance (ESR). The DFT theory used to predict the optimized atomic-skeletons for all produced complexes. Also, biological activity measurements were performed to study the important of produced compounds. The association constants of ligand at various temperatures in 50% (v/v) DMSO/H2O, 0.05 M were calculated by applying potentiometric titration. Also, the stability constants of copper (II) compounds were calculated in DMSO/H2O as a mixed solvent at various temperatures.