Facile Preparation of Mn3O4 Hausmanite Nanoplates from a New Octahedral Manganese (III) Schiff Base Complex

A novel bidentate Schiff base ligand L (L = N-(4-amino-2-chloro-phenyl)-2-hydroxybenzaldehyde) and the subsequent octahedral manganese(III) Schiff base complex MnL ₃ have been synthesized and characterized by, FT-IR spectroscopy and elemental analyses (CHN). Additionally, Schiff base ligand has been characterized by ¹H NMR spectroscopy. Thermogravimetric analysis of the ligand and its metal complexes reveals their thermal stability and decomposition pattern. Thus, the MnL ₃ complex has been investigated as a novel precursor for the facile preparation of Mn₃O₄ nanoparticles via solid-state thermal decomposition under aerobic conditions, at a temperature of ca. 450 °C The resulting Mn₃O₄ nanocrystals were characterized by FT-IR spectroscopy, X-ray powder diffraction (XRPD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The XRPD studies reveal the characteristic diffraction peaks indexed to the Mn₃O₄ hausmanite structure, while the absence of additional peaks tends to clearly indicate the high purity of the sample. In addition, the TEM/SEM investigations displayed the nanoplate shape of the rather monodisperse crystalline Mn₃O₄ nanoparticles, with an average diameter of ca. 10 nm. The statistical distribution of the nanoparticles size has to be provided with an histogram graphic.