Supported Copper(II) Arylhydrazone Complex on Synthesized Fe₃O₄ Nanoparticles Boosted with TiO₂ for the Catalytic...

For the modified progression of organo-oxidative reactions of alcohols, a monometallic copper(II) diarylhydrazone complex (CuONLCl) was constructed through the coordination of an arylhydrazone ligand (HONL) with a copper(II) ion. Its chemical structure was validated by alternative spectroscopic approaches. The heterogeneity of CuONLCl was constructed through successful surface covering of highly paramagnetic Fe₃O₄/TiO₂ nanoparticles (as CuONLCl@Fe₃O₄/TiO₂). The morphological and internal structure of the CuONLCl@Fe₃O₄/TiO₂ nanocomposite were analyzed with alternating microscopic and spectroscopic tools. The catalytic redox activity of CuONLCl (homogeneous) and CuONLCl@Fe₃O₄/TiO₂ (heterogeneous) was examined in the selective oxidative system of alcohols, e.g., benzyl alcohol (BZA), converting it to the corresponding carbonyl derivative (benzaldehyde, BZD) using H₂O₂. For optimization, the temperature, time, and solvent were adjusted to establish the highest redox activity of CuONLCl and CuONLCl@Fe₃O₄/TiO₂. The mono-oxidative product (benzaldehyde) was contaminated with the overoxidative product, benzoic acid (BZC), and other side products. The homogeneous CuONLCl catalyst adjusted its catalytic oxidative action with lower reaction time for the optimized features compared to the heterogenized CuONLCl@Fe₃O₄/TiO₂ catalyst; however, CuONLCl@Fe₃O₄/TiO₂ displayed more selective progress in yielding the mono-oxidative product. Both Cu-catalysts showed an amazing reusability with 3 and 7 attempts for CuONLCl and CuONLCl@Fe₃O₄/TiO₂, respectively. The Fe₃O₄/TiO₂ nanoparticles exhibited enhanced reusability for CuONLCl@Fe₃O₄/TiO₂ compared to CuONCl.