| This study addresses the role that the organic cations play in various room temperature ionic liquids, mainly haloaluminates and halohydrogenates. It was discovered that the physicochemical properties of the RTILs are dependent on the nature of the cations: aliphatic cation or aromatic cation.; Three new trialkyl (ethyldimethyl, diethylmethyl, triethyl) sulfonium bromides were synthesized and the physicochemical characteristics of the sulfonium bromide-based ionic liquids were investigated. Their liquid range at room temperature was successfully expanded to the Lewis basic side with triethylsulfonium bromide. Another obvious advantage is a wider NMR spectrum window for the new IL series, which offered a simple solvent for the reduction of benzophenone in a hydridic IL.; The acidic protons in the hydrogenate systems resonate at different magnetic fields depending on the cation and the halides; the temperature dependences of the spectra are closely related to the nature of the cation, with H-bonding plays a critical role. Proton on the pyridinium cation in the chloroaluminate ILs showed quadrupolar splitting in VT-1H-NMR spectroscopy, which is unique of the pyridinium cation.; Hydride chemistry in haloaluminate ILs is also dependent on the cation: hydride behaved differently in the Lewis acidic and basic ILs with different cations. In all acidic ILs, hydride reacts with the anionic species, while in basic ILs it reacts with imidazolium cation but neither triethylsulfonium cation nor pyridinium cation.; Brilliant Green dye turned out to be an acidity indicator. It can exhibit different colours in the Lewis acidic and basic ionic liquids.; Hydrocarbons including alkanes, alkenes and aromatics in the haloaluminate ILs behave uniquely. Cracking efficiency of alkanes was correlated with the molarity of the Al2X7- in the acidic haloaluminate systems with various cations apart from the temperature and reaction time factors. Alkenes alone polymerized in the acidic haloaluminates to oligomers, which explains the fate of alkenes produced during the cracking of alkanes. In the presence of aromatics, alkenes undergo Friedel-Crafts reactions generating mono-, di-, and tri-substituted products, whose distribution is controlled by the IL acidity, the quantity, and the mole ratio of the reactants and the ILs. The hydrocarbon chemistry is more dependent on the acidity of the ILs and less dependent on the cation type.; Finally, the electrochemistry of 1-butyl-3-methyl-1H-imidazolium tetrafluoroborate was investigated by constant current electrolysis for the first time: BF3 was produced as a result of BF4 - oxidation and imidazolium cation was reduced to dimers and oligomeric products via radical and carbene intermediates. Residual chloride in BmimBF4 was determined successfully by Osteryoung Square Wave Voltammetry. |
