This thesis has sought to develop the field of small-molecule activation via the rational evolution of the principle of Frustrated Lewis Pairs. In the first instance, Chapter 1 serves to give a brief introduction into the field of small molecule activation by transition metals and FLPs, with a particular focus on the most challenging and impacting small molecule substrates. Chapter 2 [1] explores the concept of frustrated Lewis pairs and Lewis acidity in more detail and specifically, the structure-reactivity trends of boron Lewis acids in FLP systems with respect to the reversible binding of H2. The motivation for this research was to develop a series of linked phosphino-borinate FLPs with a view to generating systems that may activate hydrogen in a reversible manner, furthering the scope for this class of compounds in hydrogen storage applications. Chapter 3 [2] is a continuation on the previous theme; modifying the Lewis acid component of an FLP system to facilitate previously unseen transformations and address some of the issues of existing systems. More specifically, to address the lack of catalytic systems based on the FLP paradigm. To that end, a series of cationic phosphino-aryl(alky)oxymetallocenes (PAMs) was targeted with the hypothesis that these compounds would behave as transition metal-main group FLPs. Correspondingly, the limit of this semblance to the FLP was investigated in depth in Chapter 4 [3] by demonstrating that a wide range of the reactions reported for main group FLPs could be affected by PAM complexes. In addition, several other novel reactivity patterns were discovered that are so far unprecedented for the main group analogues. In the final chapter [4], the benefits of including the unique properties of the transition metals in PAM complexes is demonstrated by an in depth study into their utility as catalysts for the dehydrogenation of amine-boranes. The fact that this reaction is only known in a stoichiometric sense for the main group systems is testament to the success of the original thesis.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:556702 |
| Date | January 2011 |
| Creators | Chapman, Andy M. |
| Publisher | University of Bristol |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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