Catechol oxidase and phenoxazinone synthase mimicking activity, X‐ray diffraction and density function theory study of pyridine and phenolate‐based manganese(II) and iron(III) complexes: Synthesis and spectroscopic characterization

Abstract

AbstractA new series of MnII and FeIII chelates containing pyridine and phenolate‐based ligands was synthesized by treating the metal salt in ethanol with the Schiff‐bases, which were formed in situ. Analytical (C, H, N, and M), thermal analysis (thermogravimetric analysis & differential thermogravimetric), and spectroscopic techniques (IR, UV–Vis, ESR) in addition to molar conductance and magnetic measurements were employed to characterize the prepared metal chelates. Mono‐nuclear metal complexes, with N5 donor containing pentadentate Schiff‐base ligands were obtained. In addition, two dibridged homobinuclear iron(III) complexes with N4O donors containing phenolate‐based ligand were successfully isolated. Six‐coordinate complex species in an octahedral environment is proposed for both MnII and FeIII metal complexes. The density function theory study was used to optimize the geometrical shapes of three of the existing metal complexes and to identify some global reactivity descriptors. In addition, spectral data of PXRD with Expo 2014's structural solution software were utilized in the structural illustration of a representative MnII and FeIII complexes. Aerobic catalytic oxidation of 4‐tert‐butylcatechol (4‐TBCH2) and o‐aminophenol under catalytic conditions was studied by using the present manganese(II) and iron(III) complexes. The synthesized MnII and FeIII chelates exhibited a promising catalytic activity and probable catalytic sequences have been discussed.