Synthesis Of Room Temperature Ionic Liquids And Its Applications In Organic Electrochemtry

As a green alternative solvent, the applications of room temperature ionic liquid have been involved in electrochemistry with electroplating, batteries, organic electrosynthesise, electrocatalysis and capacitive technologies. When it was compared with the traditional organic solvents and electrolytes, ionic liquid has excellent characteristics, such as low melting point, wide liquid temperature range, negligible vapor pressure, high thermal stability, good chemical stability and wide electrochemical window, etc. Because of high conductivity of ionic liquid, which can be used in electrosynthesise to avoid the the influence of electrolyte on the electrochemical reaction. Ionic liquids have become an important way to develop clean synthesis as alternative solvents in the electrochemical process.The electrochemical process has been become an important component of clean technologies, which due to the electrochemical reaction is usually carried out under normal temperature and pressure, toxicity and harmfulness is smaller than traditional organic synthesis. Therefore, in today with the increasingly severe global environmental problems, the important role of electrochemical technology will be demonstrated.In this paper, different ionic liquids have been synthesized by ourself and used them to replace the traditional organic solvents and its application in organic electrochemical redox reactions heve been investigated. This work combined with our lab's research subject, electrochemical behaviors of nitrobenzene and bromophenol were researched in different ionic liquids at different work electrode and some preliminary results heve been obtained:1) 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF6) ionic liquid, N-methyl-imidazole-p-toluenesulfonic acid ([Hmim]TsO) ionic liquid, and sulfuric acid ester 1-ethyl-3-methylimidazolium (EMISE) ionic liquid have been synthesized,and the structure were characterized by 1HNMR, IR and Raman spectroscopy.2) The electrochemical behaviors of nitrobenzene have been investigated in different ionic liqid of [Hmim] TsO and [Bmim]PF6. Cyclic voltammetry measurements showed that it was a irreversible electrode process in [Hmim] TsO. The electrochemical behavior with different scan rate, temperature and concentration of ionic liquid were also investigated. The transfer coefficient (α) is 0.40, diffusion coefficient (D) is 3.379×10-6cm2/s of nitrobenzene in ionic liquids was estimated by chronocoulometry measurement. And the acidity and basicity of ionic liquids have an effect on elecchemical behavior of nitrobenzene. Different products of nitrobenzene reduction can be got when use ionic liquids of different acidity.3) The electrochemical reduction dehalogenation of 2,4,6-tribromophenol in [Bmim]PF6 and EMISE ionic liquid have been investigated. Cyclic voltammetry and pulse voltammetry measurement results showed that the reductive potential of dehalogenation at silver electrode more positive than at the glassy carbon electrode. More halogen atoms can be dehalogenated at silver electrode than at GC electrode with the same experimental conditions. This result indicated that silver electrode has excellent electrocatalytical activity on electrochemical reduction of organo-halogencompounds.