CuCl-based SILCs in the thiophene oxidation – Experimental and DFT-assisted study

[Display omitted] •SILCs based on imidazole and triethylamine CuCl- and FeCl3-containing ionic liquids on silochrome catalyze oxidative desulfurization.•The catalytic reaction mechanism involves the participation of superoxide ions and copper hydroxochloride complexes.•The contribution of hydroxyl radicals to thiophene oxidation probably depends on the nuclearity of copper complexes in a catalyst. Supported ionic liquid catalysts (SILC) on Silochrome for thiophene peroxide oxidation were synthesized. They consisted of imidazolium and alkylammonium with Cu(I) and Fe(III) chloro-anions. The composition and structure of the catalysts were investigated by physicochemical methods. Quantum chemical calculations of the geometric structure and the formation energy of π-complexes of thiophene with anionic copper (I) chlorocomplexes were carried out. Based on quantum chemical calculations and experimental data with radical scavengers, the catalytic reaction mechanism has been proposed. It involves the participation of superoxide ions and copper hydroxochloride complexes. The contribution of hydroxyl radicals to thiophene oxidation probably depends on the nuclearity of copper complexes in the catalyst.