A novel dinuclear schiff base copper complex as an efficient and cost effective catalyst for oxidation of alcohol: Synthesis, crystal structure and theoretical studies

Abstract

An environmentally friendly protocol is described for an economic, practical laboratory-scale oxidation of primary and secondary alcohols to aldehydes and ketones, using a bis-chloro-bridged binuclear Cu(II) complex [(HL)Cu(μ 2-Cl)2Cu(HL)]*1.5 CH3OH as catalyst. The catalyst was prepared in situ from commercially available reagents and is characterized by single crystal X-ray analysis, FT-IR, UV-visible spectra, mass spectrometry, and powder x-ray diffraction (PXRD). The geometry of the complex has been optimized using the B3LYP level of theory confirming the experimental data. Our results demonstrated well the efficiency, selectivity and stability of this new catalyst in the oxidation of alcohols in ethanol and tert-butyl hydroperoxide (tBuOOH) as a green solvent and oxidant, respectively. Turnover number and reusability have proven the high efficiency and relative stability of the catalyst. A novel [(HL)Cu(μ2-Cl)2Cu(HL)]*1.5CH3OH complex was used as an efficient catalyst for the oxidation of alcohols. It was synthesized, using (E)-1-(((2-hydroxypropyl)imino)methyl)naphthalen-2-ol as a monoanionic and tridentate Schiff base ligand, and characterized by IR and UV-Visible spectroscopy and single-crystal X-ray analysis. The geometry of the complex was optimized using the B3LYP level of theory.