Return to search

Structural studies of ionic liquids and their use in synthesis

Ionic liquids represent a new type of solvent with a range of advantageous properties such as a large liquid range and negligible vapour pressure. This investigation is concerned with ionic liquids containing the imidazolium cation and reports both utilisation of these ionic liquids in new synthetic reactions and also investigations into the relationship between the structure and physical properties of these compounds by synthesis of a range of new imidazolium-based ionic liquids. The fluorination of organic and inorganic compounds in the 1-butyl-3-methyl imidazolium hexafluorophosphate ionic liquid was investigated, utilising calcium fluoride as the fluorinating agent. The asymmetric hydrogenation of prochiral ketones by both homogeneous and heterogeneous hydrogenation was investigated using the chiral ionic liquid 1-butyl-3-methyl imidazolium lactate. Investigations into the relationship between the structure and physical properties of imidazolium ionic liquids were performed by changing the cation or anion of the compound to synthesise a range of new ionic liquids. Changes to the cation of the ionic liquid were effected by substitution of the acidic proton at the 2-position of the imidazole ring by methyl and phenyl groups. Methylation at this position results in an unexpected increase in melting point. The crystal structures of 1-butyl-3-methyl imidazolium chloride and 1-butyl-2,3-dimethyl imidazolium chloride are reported and analysis of the extent of hydrogen bonding within these structures used to explain this phenomenon. The effect of changing the anion of the ionic liquid was investigated and the crystal structures of 1-butyl-3-methyl imidazolium bromide, 1-butyl-2,3-dimethyl imidazolium hexafluorophosphate, 1-butyl-2,3-dimethyl imidazolium tetrafluoroborate and 1-butyl-2-phenyl-3-methyl imidazolium hexafluorophosphate are reported.

Identiferoai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:660770
Date January 2001
CreatorsPringle, Jennifer M.
PublisherUniversity of Edinburgh
Source SetsEthos UK
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Sourcehttp://hdl.handle.net/1842/11279

Page generated in 0.0324 seconds