Halogen···Halogen interactions in host - guest systems
type: CreativeWork
description: For a few decades now, halogen bonds which are non-covalent interactions, have gained a lot of interest in the science community due to their applications in diverse research areas. Halogen bonding (XB) is an interaction that occurs between electron deficient halogen compounds and electron donors. This is an established non-covalent interaction in the solid and gaseous phase. In this thesis, the work presented deals with the investigation of halogen bond interactions in host-guest complexes utilising both experimental and theoretical techniques. Two host compounds, tetrakis-4-(bromophenyl)ethylene and its iodo-analogue were synthesised for the studies reported in Chapter 3, 4 and 5. Chapter 3, deals with the classification of halogen···halogen interactions using halogenated methanes as guest solvents. Here, the inclusion complexes can be classified into different types of halogen bonds depending on their geometry. Type I, which are of van der Waals in nature usually have X···X distances greater than the sum of their van der Waals radii. Type IIa and IIb are interactions which are considered to be attractive and their X···X distances are usually shorter than those of type I. The compounds obtained in Chapter 3 were used to study both the kinetics of desolvation and the kinetics of enclathration for the solid host-methyl iodide vapour reactions, to obtain their rate law and determine activation energies. In Chapter 4, the two hosts mentioned above were utilised to form inclusion compounds with a series of halogenated compounds for guest exchange reactions. The structures of the starting inclusion compounds were exposed to the vapours of the second incoming guests to form intermediate complexes and final compounds, which were used to analyse the halogen···halogen interactions in their structures. NMR spectroscopy was performed on selected crystals to monitor the guest exchange experiment and the rate law of each exchange reaction was established. Tetrakis-4-(bromopheny…
abstract: For a few decades now, halogen bonds which are non-covalent interactions, have gained a lot of interest in the science community due to their applications in diverse research areas. Halogen bonding (XB) is an interaction that occurs between electron deficient halogen compounds and electron donors. This is an established non-covalent interaction in the solid and gaseous phase. In this thesis, the work presented deals with the investigation of halogen bond interactions in host-guest complexes utilising both experimental and theoretical techniques. Two host compounds, tetrakis-4-(bromophenyl)ethylene and its iodo-analogue were synthesised for the studies reported in Chapter 3, 4 and 5. Chapter 3, deals with the classification of halogen···halogen interactions using halogenated methanes as guest solvents. Here, the inclusion complexes can be classified into different types of halogen bonds depending on their geometry. Type I, which are of van der Waals in nature usually have X···X distances greater than the sum of their van der Waals radii. Type IIa and IIb are interactions which are considered to be attractive and their X···X distances are usually shorter than those of type I. The compounds obtained in Chapter 3 were used to study both the kinetics of desolvation and the kinetics of enclathration for the solid host-methyl iodide vapour reactions, to obtain their rate law and determine activation energies. In Chapter 4, the two hosts mentioned above were utilised to form inclusion compounds with a series of halogenated compounds for guest exchange reactions. The structures of the starting inclusion compounds were exposed to the vapours of the second incoming guests to form intermediate complexes and final compounds, which were used to analyse the halogen···halogen interactions in their structures. NMR spectroscopy was performed on selected crystals to monitor the guest exchange experiment and the rate law of each exchange reaction was established. Tetrakis-4-(bromopheny…
author: Amombo Noa, Francoise Mystere
language: eng
date published: 2017
date modified: 2026-07-22T22:23:34Z
provider: University of Cape Town
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Department of Chemistry

PropertyValue
property ID: Handle
value: http://hdl.handle.net/11427/27462