Synthesis and Characterization of Fe₃O₄/Carbon Dot Supported MnO₂ Nanoparticles for the Controlled Oxidation of Benzyl Alcohols

Abstract

In recent past, magnetic catalyst has gained much attention because it can be easily separated from the reaction mixture. Herein we report a facile synthesis of magnetic carbon dot supported MnO 2 nanoparticles for the oxidative transformation of organic compounds. In the actual synthesis, initially Fe 3 O 4 nanoparticles were prepared by microwave assisted method and carbon dots were prepared instantaneously from glucose by simple incineration under closed condition. The synthesized carbon dots were coated over iron oxide nanoparticles via sonochemical deposition method. Further, magnetic carbon dot supported MnO 2 nanocomposite was synthesized by conventional homogeneous precipitation using potassium permanganate. The synthesized nanocomposite material was characterized using FT-IR, SEM, TEM, XRD and VSM techniques. The catalytic efficiency of the nanomaterial was successfully demonstrated for the oxidation of benzyl alcohols to benzaldehydes. The advantages of this method include, controlled oxidation of alcohols to aldehydes with broad substrate scope, the use of molecular oxygen as a green oxidant and beyond that a facile magnetic separation of the catalyst material. Moreover, the catalyst can be recycled for 5 times without much loss in its efficiency.

Catalytic Selective Oxidation of Primary and Secondary Alcohols Using Nonheme [Iron(III)(Pyridine‐Containing Ligand)] Complexes

“…This reaction has been widely studied in recent years, but good results with high selectivities were obtained mainly with heterogeneous catalysts. [8,30] The lack of good homogeneous catalysts capable of yielding selectively benzaldehyde in such a reaction prompted us to test our iron(III) complexes 3a-b, choosing as a starting point the conditions very close to what we have already recently reported for the epoxidation/dihydroxylation reaction of alkenes. Reactions were performed by adding the catalyst and the benzyl alcohol to the solvent and then the oxidant (H 2 O 2 , 30 %) by slow addition with a syringe pump or by repeated single additions.…”

“…The reagents of choice as green oxidants are by far O 2 and H 2 O 2 since they possess the highest oxygen content. [5] For instance, in the last five years, significant advances have been achieved in the oxidation of benzyl alcohols to benzaldehydes, using homogeneous iron(II), [6] iron(III), [7] and copper(II) [7a] complexes, metallacarboranes, [7d] supported nanoparticles, [8] MOF, [9] and substoichiometric organic reagents. [10] In particular, the use of iron, [11] the most abundant transition metal on earth, and its complexes in organic synthesis, biochemistry, and also in industrial application is of particular interest.…”

“…[ 4 ] The reagents of choice as green oxidants are by far O 2 and H 2 O 2 since they possess the highest oxygen content. [ 5 ] For instance, in the last five years, significant advances have been achieved in the oxidation of benzyl alcohols to benzaldehydes, using homogeneous iron(II), [ 6 ] iron(III), [ 7 ] and copper(II) [ 7a ] complexes, metallacarboranes, [ 7d ] supported nanoparticles, [ 8 ] MOF, [ 9 ] and substoichiometric organic reagents. [ 10 ]…”

Preparation of Fe3O4@C‐dots as a recyclable magnetic nanocatalyst using Elaeagnus angustifolia and its application for the green synthesis of formamidines

“…Recently, there has been enormous attention focused on the usage of magnetite nanoparticles in the fields of nanoscience because these magnetic nanocatalyst systems contain distinctive features including simple synthesis, high surface area, biocompatibility, low toxicity, superparamagnetic performance, simple separation (through an external magnet), and is reusable. [ 30–37 ]…”

Immobilization of Polyoxometalate onto Modified Magnetic Nanoparticles: A New Catalyst for the Synthesis of Dihydropyranopyrazole Derivatives

“…Magnetic nanocatalysts are easily removed from resulting mixtures with an extrinsic magnetic field and have emerged as ideal catalysts or supports. [40][41][42][43][44][45][46][47] Polyoxometalate (POMs) are well-known transition metal oxygen clusters and have been widely used in the catalytic field. Polyoxometalates are composed of cations and polyanion clusters with structural diversity, in which the oxometal polyhedral of MO x (x = 5, 6) are the basic construction units.…”