Theoretical Study On The Electronic Structures Of Alkylimidazolium Based Ionic Liquids And Their Catalytic Reaction Mechanism

Using ab initio and Density Functional Theory (DFT), under gas phase, theoretical studies are performed to investigate the ion-pair electronic structures of four alkylimidazolium based ionic liquids including 1 -ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium hexafluorophosphate,1-butyl-3-methylimidazolium hexafluorophosphate and 1-ethyl-3-ethylimidazolium tetrafluoroborate. Furthermore, the reaction mechanisms of the double bond isomerization of pentene catalyzed by 1-ethyl-3-methylimidazolium of the ionic liquids are discussed.Ionic liquids (ILs) consist exclusively of anions and cations and do not contain any neutral molecule. Alkylimidazolium class of ILs, believed as "designable solvents", possess tunable properties by changing the branched chains attached to the heterocyclic unit or the anion and have been regarded to be potentially environmentally benign catalysts or media. In this thesis, quantum chemistry calculations are performed to study the electronic structures of four alkylimidazolium based ionic liquids. Using ab initio and DFT, the ion-pair electronic structures under gas phase of the four ILs are optimized at several different basis set, respectively. The computational results show that there exist...