Bifunctional Ionic Liquid Catalyst Containing Sulfoacid Group and Hexafluorotitanate for Room Temperature Sulfoxidation of Sulfides to Sulfoxides Using Hydrogen Peroxide

A bifunctional ionic liquid (IL), bis-[N-(propyl-1-sulfoacid)-pyridinium] hexafluorotitanate (1), was synthesized and proved to be an efficient and recyclable catalyst for room temperature sulfoxidation of sulfides using H2O2 as the oxidant. The synergetic catalysis derived from the incorporated functional moieties in the IL structure was embodied in 1. The UV–vis and Raman spectra indicated that the remarkable catalytic performance of 1 was related to the easy generation and regeneration of the active peroxo-Ti species.