Hexacyanoferrate-based.

Two hexacyanoferrate-based , [C4Py]3Fe(CN)6 and [C16Py]3Fe(CN)6, were synthesized and characterized using Fourier transform infrared and mass spectroscopies and CHN analysis. They were employed as Fenton-like catalysts in extraction and catalytic oxidative of model oil with dibenzothiophene (DBT), benzothiophene (BT), 4,6-dimethyldibenzothiophene (4,6-DMDBT), 4-methyldibenzothiophene (4-MDBT) and 3-methylbenzothiophene (3-MBT) as substrates. Various polar solvents, such as , water and organic solvents, were applied to choose a suitable extractant. The results showed the removal of DBT reached 97.1% with [C4Py]3Fe(CN)6 as a catalyst and 1- n-octyl-3-methylimidazolium hexafluorophosphate ([C8mim]PF6) as an extractant under optimal conditions. The activity of followed the order DBT > 3-MBT > BT > 4-MDBT >4,6-DMDBT. The effect of water content on was investigated by adding various concentrations of H2O2. It was found that excess water had a positive effect on but the catalysts were less sensitive than [FeCl4−]-based catalysts to water. The mechanism was studied using electron spin-resonance spectroscopy and gas chromatography-mass spectrometry. O2•− may be the active oxygen species in the catalytic oxidative process and the oxidation products of various were the corresponding sulfoxides and sulfones. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]