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Title: | THE REACTIONS OF SOME ACTIVATED AROMATIC HALIDES WITH PIPERIDINS, AND N-BUTYLANINE IN DIPOLAR APROTIC AND DIPOLAR PROTIC SOLVENTS |
Authors: | ADENLE, M. A. |
Issue Date: | 1975 |
Abstract: | The reactions of 2-chloro-5-nitro pyridine with piperidine have been studied in acetone and in nethanol. In acetone, the rate constants are measured as a function of the anine concentration. In methanol, the Arrhenius parameters are obtained. In methanol, except for a very slight (almost negligible) downward trend of rate constants at very high concentration which is explained in terms of Charge - transfer complexes, there is no base catalysis and the observed rate constants are the rates of formation of the intermediate complex. The rates of reaction of 1-X-2, 4-dinitrobenzene (X=F, Cl) with piperidine and n-butylamine in methanol, acetone, and chloroform (stabilised and destabilised) have been measured as a function of the amine concentration. In acetone, the reactions of both substrates with piperidine show true base catalysis with K3/K2 > 50 in both cases. In Chloroform with n-butylamine, there is very little rate increase with increasing amine concentration. For both Substrates, K3/K2=3. This is explained in terms of hydrogen-bonding in the intermediate state. In methanol, the reaction of the chloro Substrate with piperidine gives a small linear increase of rate constants with increasing amine concentration; while for the fluoro substrate, the graph of rate constants against amine concentration gives a doubly sloped curve. This is due to some special unknown medium effects. In acetone, the reactions with n-butylamine give rather peculiar results. The chloro substrate appears to be more sensitive to catalysis by amine than the fluoro substrate - a Situation hitherto unknown. In general, for the reactions in methanol and Chloroform, there is not much base influence; while those in acetone are dependent on the base strength. |
Description: | A THESIS SUBMITTED TO THE UNIVERSITY OF IBADAN FOR THE DEGREE OF MASTER OF SCIENCE |
URI: | http://ir.library.ui.edu.ng/handle/123456789/4683 |
Appears in Collections: | Theses |
Files in This Item:
File | Description | Size | Format | |
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(109) ui_thesis_adenle_m.a._reactions_1975.pdf | 24.03 MB | Adobe PDF | View/Open |
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