Synthesis and characterization of Manganese(III) tetraphenylporphyrinato chloride immobilized on multi-wall carbon nanotubes, and its application as an efficient and reusable catalyst in the biomimetic oxidation of sulfides: A comprehensive experimental and computational study

摘要

In the present study, manganese(III) tetraphenylporphyrinato choloride, was immobilized on multiwall carbon nanotubes by covalent bonding. The structures of [Mn(TPP)Cl]@AP-MWC catalyst was confirmed by FT-IR, UV-vis spectroscopic techniques and scanning electron microscopy (SEM). Then, the ability of this novel heterogeneous catalyst was investigated in the oxidation of linear and cyclic sulfides under magnetic stirring conditions. Also, the DFT computational method (B3PW91 method with LanL2DZ basis set) was used for further analysis of this catalyst. Based on this method, the molecular geometries and frequencies of vibrations, chemical shifts, absorbed wavelengths, hyper-conjugative interactions, electron transitions between electron surfaces, positive and negative charges, HOMO and LUMO gap, wavelength (lambda), chemical potential (mu), ionization energy (IE), global hardness (eta), global softness (S), electrophilicity index (omega) and electronegativity (alpha) of the most intensity electronic transition for carbon nanotubes and [Mn(TPP)Cl]@AP-MWCNT catalyst were calculated. The activity and efficiency of this catalyst were then investigated in the biomimetic oxidation of sulfides. The [Mn(TPP)Cl]@AP-MWC heterogeneous catalyst showed the advantages such as high efficiency, good to excellent yield, short reaction times, easy separation and high reusability of the catalyst. (C) 2020 Elsevier B.V. All rights reserved.