Solvent effects on hydrogen bonding
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Date
01/07/2019Item status
Restricted AccessEmbargo end date
01/07/2020Author
Meredith, Nicole Yvette
Metadata
Abstract
Determining the strength of H-bonds in solution can be challenging due to competing
solvent interactions, especially in biologically relevant polar solvents such as water. In
this thesis, various molecular balance designs are used to quantify the strength of H-bonds
in solution.
Chapter 1 presents a literature review on optimising H-bond interactions, with a focus
on experimental systems previously used to quantify the strength of H-bonds in
different solvents.
Chapter 2 investigates the effectiveness of implicit solvation models for predicting the
thermodynamic behaviour of different solvents using a simple series of molecular
balances. Computationally determined equilibrium energies are compared with
experimental values. Generally, the implicit solvation models are found to have good
correlations in non-polar solvents, but poorer results are observed when moving onto
more polar solvents.
Chapter 3 provides an experimental study of organic and aqueous solvent effects on
intramolecular H-bonding between amide and anilines. Several series of compounds
are investigated, where both H-bond geometry and conformational flexibility are
varied. Thermodynamic information is derived from the balances and the experimental
data examined further by plotting against computational results and fitting with a semi-empirical
solvation model.
Chapter 4 presents a study on solvent effects on H-bond cooperativity. A phenol,
catechol and pyrogallol molecular balance series are synthesised and experimental
energies are derived. Three different types of behaviour are observed depending on the
acceptor ability of the solvent.