The theoretical and experimental work in this thesis is primarily aimed at
i) the quantification of the strengths of a number of hydrogen bonded
systems, and ii) exploring the relationships that exist between the various
physico-chemical properties determined in this study, which are related to
the hydrogen bonding phenomenon.
To this end a three part study of some hydrogen bonded systems has been
undertaken. The study involves using a number of theoretical and
experimental procedures, including a theoretical ab initio molecular orbital
study, infrared spectroscopic determinations and a thermodynamic
investigation involving measuring enthalpies and volumes of mixing and
applying a theoretical model of interacting liquid mixtures.
Conclusions based on ab initio molecular orbital theory, thermodynamic and
infrared spectroscopic results conducted in this work include:
i) the proton donating ability of the three hydrogen donor moieties
studied in this work decreases in the order O-H > N-H ~ S-H,
ii) the proton accepting competence of the three electron donor atoms
considered in this work decreases in the order N > 0 > S in all cases
except in the liquid phase systems involving dipropylamine and
propane-1-thiol as proton donors, where the proton accepting ability
of the atoms is in the opposite order i.e. S > 0 > N, and
iii) a direct correlation exists between the shift in the A-H stretching
wavenumber and the hydrogen bond interaction energy.
. Although a number of factors influence the stability of the hydrogen bond,
it was also tentatively concluded that in liquid phase systems involving
weakly self-associated hydrogen bond donor molecules, the available surface
area of the proton accepting atom becomes the dominant strength
determining factor, otherwise factors such as basicity and electronegativity
dominate. / Thesis (Ph.D.)-University of Natal, Durban, 1995
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ukzn/oai:http://researchspace.ukzn.ac.za:10413/4678 |
| Date | January 1995 |
| Creators | Bricknell, Bradley Colin. |
| Contributors | Ford, T. A., Letcher, Trevor M. |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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