Haskins, Rebecca Jane (2001) Microelectrochemical studies of atom transfer and chain transfer catalysts. PhD thesis, University of Warwick.

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Abstract

The purpose of the work described in this thesis was to measure standard electrode
potentials and rate constants for various systems, based around cobalt and copper
centred catalysts. The intention was to increase understanding of these two different
types of complexes, with the knowledge described herein aiding in catalyst and
system design.
Two main techniques have been used, those of UME voltammetry and SECM. The
UME measurements proved technically simple and were used to provide information
on redox kinetics and coupled solution reactions. Conversely, the SECM experiments
were more complex to perform but allow more complicated systems to be studied.
The results obtained in Chapter 3 provide further information about the properties of
[Cu] ATP catalysts. Enhanced information could be obtained with better knowledge
of the values ofE1I2 or F!., but the work has shown that in organic solvents even
simple parameters are difficult to obtain due to complexities such as ion pairing.
The theme of Chapter 4; the reaction of [CUll] with Cu
o
had previously been
unexamined. This reaction has been characterised and provides new information of
the processes involved in adding Cu
o
to ATP reaction mixtures. A computer
simulation was applied that described the theoretical behaviour of an oxidative
etching event. A good fit was obtained between experiment and theory at large values
of d/a and at short times. The potentials of a number of [CuI]/[CUIl ]and [Cul]/[CUO]
redox couples have been measured in order to understand the substrate potential
response during the SECM etching process.
The rate of reaction of a number of different [COl] with E2mB has been measured in a
range of solvents, as described in Chapter 5. The solvent was seen to have a great
effect on the behaviour of each system, stabilising the formation of R[Colll ], such that
two reduction processes became evident where mma was the solvent. Such [Co]
species are commonly used as C - C bond forming reagents and therefore knowledge
of their behaviour in certain solvents is invaluable. Additionally the [Colt E2mB
system may be used as an initiator/catalyst system for polymerisation reactions, either
in homogeneous or emulsion solutions.

Item Type:	Thesis (PhD)
Subjects:	Q Science > QC Physics Q Science > QD Chemistry
Library of Congress Subject Headings (LCSH):	Electrochemical analysis, Electrodes
Official Date:	September 2001
Dates:	Date Event September 2001 Submitted
Institution:	University of Warwick
Theses Department:	Department of Chemistry
Thesis Type:	PhD
Publication Status:	Unpublished
Supervisor(s)/Advisor:	Unwin, Richard
Sponsors:	Engineering and Physical Sciences Research Council (EPSRC)
Extent:	xvi, [271] leaves : illustrations
Language:	eng

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