Experimental and theoretical investigation of the catalytic performance of reduced Schiff base and Schiff base iron complexes: Transformation to magnetically retrievable catalyst

Abstract

Catalytic efficiencies for the oxidation of alcohols of a mononuclear Schiff base iron complex (FeL) and an analogous reduced Schiff base one (FeRL) have been assessed experimentally and theoretically. The structure ofFeLhad been previously reported by our group. Here, we have synthesized the reduced Schiff base complexFeRLwhere RL = 2,2′‐[(2,2‐dimethyl‐1,3‐propanediyl)bis (iminomethylene)]bis[2,4‐dichlorophenol]. The single‐crystal X‐ray analyses of the new complex reflected its mononuclear nature and an umbrella‐like framework. Homogeneous catalytic experiments revealed the superiority ofFeRLoverFeL, which could be rationalized by comparing the stability of the corresponding FeV = O species characterized through density functional theory calculations. Based on its excellence,FeRLwas chosen for surface modification of magnetite nanoparticles coated with dopamine to generate magnetically recoverable Fe3O4@Dopa@FeRL (FDFeRL).FDFeRLwas characterized with the aid of field emission scanning electron microscopy, transmission electron microscopy, powder X‐ray diffraction and Fourier‐transform infrared spectroscopy and efficiently used in the oxidation of a variety of alcohols. Our synthesis of the supported catalyst can be deemed as a simple, economical and sustainable one. Catalyst recovery could be easily achieved by simple application of a magnet.FDFeRLcould be reused several times without compromising its catalytic efficiency.