Unsymmetric bi-functional Mn-salen complex bearing TEMPO and Mn-complex for the synthesis of magnetic Mn/TEMPO-doped Fe 3 O 4 NPs: a simple catalyst (magnetic oxidant) for selective oxidation of alcohols

In this paper, a novel unsymmetric Mn (III) /TEMPO-salen complex bearing three hydroxyl groups was served as a reducing agent for the efficient preparation of Mn/TEMPO-doped Fe 3 O 4 NPs in situ. This protocol suggests an in situ Mn (III) /TEMPO-salen complex doping via a co-precipitation method for the preparation of magnetic NPs that was studied and confirmed by FTIR, TGA, VSM, ICP, TEM, XRD, UV–Vis, BET, DLS, zeta potentials, EDX, and XPS analyses. The resulting Mn/TEMPO-doped Fe 3 O 4 NPs was found as an efficient nanocatalyst for the selective oxidation of benzyl alcohol to the corresponding carbonyl and carboxylic acid by the change of oxidant type. In the presence of oxone as an oxidant, the alcohol oxidation proceeds to carboxylic acid, while underwent O 2 bubbling, carbonyl product was obtained selectively. Mn/TEMPO-doped Fe 3 O 4 could be recycled for at least 8 consecutive recycles without any considerable reactivity loss. Graphical abstract Unsymmetric Mn (III) /TEMPO-salen complex was used as a reducing agent for the synthesis of Mn/TEMPO-doped Fe 3 O 4 NPs in situ as an efficient catalyst for alcohols oxidation selectively