A Homogeneous Mixture Composed of Vanadate, Acid, and TEMPO Functionalized Ionic Liquids for Alcohol Oxidation by H 2 O 2

The functionalized ionic liquids (ILs) of N ‐ n ‐dodecyl pyridinium vanadate ( 1 ), N ‐(propyl‐1‐sulfonic acid) pyridinium tetrafluoroborate ( 2 ), and 4‐(propanoate‐2,2,6,6,‐tetramethylpiperidine‐1‐oxyl) pyridinium tetrafluoroborate ( 5 ) were synthesized. The mixture of 1 , 2 , and 5 in [Bpy]BF 4 yielded the compatible IL compositions (ILCs) as a homogenous mixture, which proved to be an efficient catalytic system for oxidation of a wide range of alcohols using H 2 O 2 . With the aid of 2 and 5 , 1 in [Bpy]BF 4 could easily be recovered and reused for at least six runs without a loss in activity. UV/Vis spectroscopic analysis indicated that the role of 2 was to promote the formation of the active peroxo V V species, which is responsible for substrate activation, and the role of 5 was to oxidize the low‐valent vanadium(II–IV) species to regenerate 1 .