Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.555704
Title: UHV spectroscopic studies of amino acid-based ionic liquids
Author: Hurisso, Bitu Birru
Awarding Body: University of Nottingham
Current Institution: University of Nottingham
Date of Award: 2011
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Abstract:
The synthesis of a range of amino acid-based ionic liquids (AAILs) each containing a 1-alkyl-3-methylimidazolium cation have been completed. The synthesis of these materials was carried out by a three step approach via the dialkylimidazolium hydroxide. New synthetic procedures and analytical methods are described. Each of the AAIL samples have been fully characterised by traditional analytical techniques including multi- nuclear NMR, MS and polarimetry. The stability of the AAILs under ultra high vacuum (UHV) has been investigated; furthermore stability during X- ray beam irradiation has also been studied. XPS studies of each of the AAILs have been completed and the stoichiometry of each sample confirmed. A modified C is fitting protocol was developed, to include contributions from additional C, Nand 0 in the anion, this protocol was subsequently used to investigate the electronic environment of each element present. The measured BEs of the Ncation is peak of AAILs were all close to each other, within experimental error, indicating that the R group of the amino acid-based anion has very little effect on cation-anion interaction. The cation-anion interaction in AAILs was compared to that observed in non-functionalised ILs and was shown to be similar to that of halide-based dialkylimidazolium ionic liquids. The effect of sample exposure under X-ray irradiation for prolonged periods of time was studied, the magnitude of damage was quantified by comparison of N is XP spectra, supported by peak fitting with three components. The nature of the damage and its dependence on the chemical structure of the AAIL was established. The maximum exposure time (tmax,5%) at which point each sample was stable to X-ray irradiation was determined, this was used to develop longer scan sequences, particularly in the case of angle resolved, ARXPS, experiments. ARXPS of amino acid-based ionic liquids is reported for the first time. ARXPS of four AAILs of the general type [CsC1Im][AA], with differing amino acid-based anions, all showed that the alkyl chain is preferentially oriented above the imidazolium cation and sticking out towards the vacuum. The anion was shown to sit slightly above the imidazolium cation, but below the alkyl rich surface.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.555704  DOI: Not available
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