Thesis

The application of density functional theory for understanding organic reactivity : nitration, super electrophiles, iridium catalysts, methanol formation

Creator
Awarding institution
  • University of Strathclyde
Date of award
  • 2013
Thesis identifier
  • T13780
Qualification Level
Qualification Name
Department, School or Faculty
Abstract
  • In this thesis, the ability of modern density functional theory to model organic reaction mechanisms is examined. The insights that can be obtained from computational chemistry range from the very nature of the mechanisms - the fundamental forces that drive the reaction forward - through to the role of the environment and the properties of the resulting molecules. However, the importance of these insights is most readily displayed through their application to challenging experimental problems. Therefore, the projects that are described in this work are all associated with experimental studies that are in a position to utilise the insights obtained. In the study on the nitration of 6-chloropyrimidine-4(3H)-one (Chapter 3), it was shown that the inductive effect can be employed in some instances to provide a mechanistic explanation for reactivity. This was observed to be relevant where there is a moiety within the molecule, which either withdraws or donates electronic density from or to this group. In the study on the superelectrophilic activation in amidine dications (Chapter 4), it was shown that relative energetics with respect to formation of reactant/product complexes and transition states can be influenced by the presence or absence of associated counterions. In the study on the use of iridium based catalysts for hydrogen isotope exchange (Chapter 5) the role of solvent molecules in affecting the reactivity was assessed. This study led to the rationalization and selection of a preferred and beneficial solvent for carrying out these reactions. In the formation of methanol from CO and CO2 (Chapter 6) an explanation in terms of relative energetic changes of a series of steps in a novel route to Methanol formation has been reported. It has been shown that the relative energetics of these set of reactions are within a satisfactory range for the process to proceed as represented experimentally.
Resource Type
DOI
Date Created
  • 2013
Former identifier
  • 1036338

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