Hobson, Katie;
(2021)
Exploring the Synthesis, Structure and Reactivity of a Series of Aluminium Amidinates.
Doctoral thesis (Ph.D), UCL (University College London).
Preview |
Text
Hobson_Katie_Thesis_2021_Corrections_Final.pdf - Accepted Version Download (7MB) | Preview |
Abstract
The work presented in this thesis relates to the synthesis of sterically encumbered aluminium amidinate complexes and investigating their propensity to catalyse hydroboration reactions or form aluminium-aluminium multiple bonds. The sterically encumbered 2,6-diphenylmethyl-4-methylphenyl substituent (referred to as Ar*) was employed to synthesise a range of symmetric and asymmetric amidine ligands which, upon complexation to aluminium reagents, yielded a series of aluminium hydride and alkyl amidinate complexes. These compounds were characterised spectroscopically and crystallographically, and any discrepancies between the solid- and solution-state properties have been accounted for. The propensity of these compounds to catalyse the hydroboration of phenylacetylene using 4,4,5,5-Tetramethyl-1,2,3-dioxaborolane (HBpin) was investigated. The aluminium hydride complexes were found to be active catalysts for this reaction and the alkyl compounds were pre-catalysts. Rates of reaction varied across this series of compounds which can be tentatively linked to the steric encumbrance of the flanking aryl substituents. Where deviations from this trend were observed, they could be rationalised by assessment of the solution-state stability of the complexes. Detailed experimental investigations were conducted to elucidate the mechanism of action. Variation in the observed mechanistic pathways was observed across this seemingly-similar family of compounds, with these pathways being different to previous literature reports of aluminium-catalysed hydroboration reactions. Finally, these compounds were explored for their viability as precursors to form aluminium-aluminium bonds. Aluminium amidinate and -diketiminate dihydrides were reacted with a known aluminium(I) reagent to obtain a series of amidinateAl-Al--diketiminate and asymmetric -diketiminateAl-Al--diketiminate dialumane complexes with varying steric encumbrance. Preliminary spectroscopic analyses are discussed, with ongoing investigations for complete characterisation and further reactivity.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | Exploring the Synthesis, Structure and Reactivity of a Series of Aluminium Amidinates |
| Event: | UCL |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Additional information: | Copyright © The Author 2021. Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Chemistry |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10139220 |
Archive Staff Only
 |
View Item |
