Solvent Free, Selective Oxidation of Styrene Catalyzed by Cobalt Acylpyrazolone Supported onto Neutral Alumina: Synthesis and Spectral Characterization

The present work describes the synthesis of the Cobalt acylpyrazolone complex supported over neutral alumina and its use as a heterogeneous catalyst for selective oxidation of styrene. The catalyst mentioned here was characterized by various physicochemical techniques such as FT-IR, TGA, CV, SCXRD, PXRD and BET. This heterogeneous catalyst has successfully been used to oxidize styrene to benzaldehyde in a solvent-free condition with good conversion (87 %) and high selectivity (90 %) using H2O2 and TBHP as oxidants. The effects of the reaction parameters (catalyst concentration, reaction duration, and temperature) have also been investigated. The existing complex was discovered to be recyclable and sustainable with no change in conversion or selectivity for benzaldehyde. FT-IR spectra of the regenerated catalyst indicated that the catalyst was undegraded and stable after the reaction. The novel feature of the current work reported in this paper is the selective oxidation of styrene without the need for solvents under mild conditions. Single Crystal Analysis. Cobalt complex [Co(HLB)2(H2O)2] with distorted octahedral geometry was synthesized using a novel HLB ligand. Their crystal features and parameters were examined using various characterization techniques. Catalytic activity has been performed on the synthesized complex. image