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Title: The effect of fluorine substitution on some properties of β-diketones
Author: Patel, Suryakant Pursottambhai
ISNI:       0000 0001 3476 3258
Awarding Body: University of Surrey
Current Institution: University of Surrey
Date of Award: 1973
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This thesis is divided into five sections. After the General Introduction Chapter 1 describes the synthesis of a series of beta-diketones. The physical and analytical data for the compounds is also given. In Chapter 2 the thermodynamic acidities of acetyl-acetone, acetyltrifluoroacetone, hexafluoroacetylacetone, benzoylacetone and a series of meta- and para-substituted benzoyltrifluoroacetones are determined using a standard potentiometric titration method. In some cases measurements have been made over a temperature range. Chapter 3 is an account of the way in which the water catalysed rates of ionisation of these same beta-diketones vary. The results clearly show the effects of fluorine substitution in that the activation energies are much higher (by ~ 6K. cals/mole) than for the unfluorinated compounds. Although fluorine subsitution leads to an increase in acidity, the rates of ionisation are slower, reflecting the increased tendency to form hydrates. This makes enolisation more difficult. Chapter 4 is concerned with various aspects of the hydration of the beta-diketones. Both rates of hydration and dehydration have been measured and these investigated as a function of medium composition. Chapter 5 brings together values of the entropies of activation of various carbon acids as obtained from measurements of the rates of ionisation. The values of DeltaS+ are discussed and it is shown that they can be used as a criterion of reaction mechanism.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available