The stability of covalently immobilization of TEMPO on the polymer surface through ionic liquid linkage: a comparative and model research
作者：Danjie Li, Xianbo Shen, Liang Chen, Huanchang Jiang, Jianli Wang*
關(guān)鍵字：alcohols; heterogeneous catalyst; ionic liquid; recyclability; stability
論文來(lái)源：期刊
發(fā)表時(shí)間：2015年
Covalently immobilizing the active sites or ligands on a polymer surface is an efficient strategy to achieve a full use of expensive organic parts. In this work, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) was anchored onto polystyrene beads through an ether bond or an ionic liquid bridge. We quantitatively compared their thermal stabilities at nitrogen atmosphere and their chemical stabilities in a biphasic oxidation surrounding. It was found that the ionic liquid-bridged TEMPO exhibited an additional advantage of stability and could be reused for 30 consecutive recycles with a conversion ratio above 90% without any significant loss under the condition of the Montanari oxidation system (NaClO/NaBr, CH2Cl2/water), and the overall reaction time exceeded 2700 min.