Synthesis and characterization of some novel Mn(III) glycinato complexes with catalytic applications

Abstract

Tris(glycinato)Mn(III) and its mixed ligand complexes with azido-, thiocyanato-, chloro- and bromo- groups have been synthesized and characterized by UV–Vis spectrophotometry, IR spectrophotometry, elemental analysis, magnetic susceptibility measurements, thermal analysis, Dart-mass spectrometry, EPR spectral studies, and X-ray powder diffraction studies. The molar extinction coefficient values of the complexes are in the range of spin allowed 5T2g → 5Eg transitions. The magnetic susceptibility measurements of all the complexes confirmed the presence of four unpaired electrons and high spin d4 systems. Room temperature EPR spectrum gives g isotropic value 2.002 indicative of octahedral geometry for the complex. PXRD studies suggest monoclinic system with space group P21/c with a = 9.1382(60) Å, b = 15.5340(11) Å, c = 10.2576(68) Å, and β = 110.598(15)°. The particle size of the complexes lies in the range 26.60–38.79 nm. The tris(glycinato)Mn(III) is an efficient heterogeneous catalyst for decolorization of Xylenol Orange and Methyl Red in the presence of H2O2. It also initiates polymerization of acrylonitrile.