Electrochemical Investigation of Ketone Complexation by Lewis Acids in a Chloroaluminate Ionic Liquid

摘要

A comparative study of 9-fluorenone electrochemistry in the AlCl_3 : 1-ethyl-3-methylimidazolium chloride system has been carried out by addition of the Lewis acids AlCl_3 and HfCl_4 to fluorenone initially in the neutral melt. It has been found that each Lewis acid is capable of forming a complex with fluorenone, resulting in a positive peak potential shift for the reduction process. Neither these peak potentials, nor the colors of the complexes, are exactly the same, indicating that distinct complexes are formed for HfCl_4 and AlCl_3. There is some possibility of interaction of HfCl_4 with the chloroaluminate melt to form the Lewis acid Al_2Cl_7~-, but this route seems to play a minor role in the present case.