Catalytic behaviour of a novel Fe(III) Schiff base complex in the mild oxidation of cyclohexane

摘要

The complex [Fe-III(HL)Cl-2(DMF)]Cl.DMF (1) was synthesized by reaction of Fe(III) chloride with a dimethylformamide solution of the Schiff base aminoalcohol HL (2-[(E)-{[2-(piperazin-1-yl)ethyl]imino}-methyl]phenol) and characterized by single crystal X-ray diffraction analysis, thermogravimetry and spectroscopic methods. The catalytic investigations disclosed a marked activity of 1 towards oxidation of cyclohexane with hydrogen peroxide, under mild conditions, with yields based on cyclohexane up to 37% and TONs (turnover numbers) up to ca. 900. Kinetic experiments and selectivity parameters led to the conclusion that hydroxyl radicals are active (attacking C-H bonds) species in the studied catalytic reaction. Kinetic and UV/Vis spectrometry data revealed a complex nature of the processes occurring in the catalytic system, including the transformation of 1 into catalytically active species.