Barhdadi R.,CNRS East Paris Institute of Chemistry and Materials Science |
Troupel M.,CNRS East Paris Institute of Chemistry and Materials Science |
Comminges C.,CNRS East Paris Institute of Chemistry and Materials Science |
Laurent M.,CNRS East Paris Institute of Chemistry and Materials Science |
Doherty A.,Queenss University of Belfast
Journal of Physical Chemistry B | Year: 2012
Two electrochemical techniques have been used to measure the pKa of N-bases in several ionic liquids (ILs). The first method corresponds to a potentiometric titration of a strong acid with the N-base using a platinized Pt indicator electrode immersed in the IL solution and maintained under dihydrogen atmosphere via gas bubbling. The second approach involves performing cyclic voltammetry at a platinized Pt electrode in a solution containing both strong acid and the conjugate weak acid of the N-base. Values of pKa obtained by one or the other approach are in good agreement with each other. The experimental data clearly demonstrated that acid/base chemistry in ILs is similar to that observed in molecular nonaqueous solvents; i.e., the relative strengths of the bases were in the right order and spaced (ΔpK a). It was also observed that the strength of N-bases is highly dependent on the anion of the ionic liquid; this observation indicates that pH-dependent reactions could be controlled by the appropriate choice of anion for bulk ILs or as an added co-ion to bulk IL. © 2011 American Chemical Society.
Doherty A.P.,Queenss University of Belfast |
Diaconu L.,Queenss University of Belfast |
Marley E.,Queenss University of Belfast |
Spedding P.L.,Queenss University of Belfast |
And 2 more authors.
Asia-Pacific Journal of Chemical Engineering | Year: 2012
Rising costs and green environmental concerns have focused attention on more efficient way of producing chemical products. Room temperature ionic liquids (RTILs), especially in combination with electrochemical activation, provide promise of reduction pollution in processing because of their recyclability and low vapour loss factors. The fundamental and applied aspects of electrolytic processing in ionic liquid media are discussed using data from various direct and catalytic redox processes. It is shown that ionic liquids are potentially very useful for performing important redox transformations, for example alcohol oxidations, carboxylations and CO 2 capture. These results indicated that electrolytic transformations in RTIL media are feasible which present opportunities for developing new real chemical processing applications. The opportunities and challenges for electrochemical engineers in this field are outlined and discussed. Copyright © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.