Publication Date

1995

Document Type

Dissertation/Thesis

First Advisor

Kevill, Dennis N.

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Chemistry

LCSH

Organophosphorus compounds; Solvolysis; Organochlorine compounds

Abstract

The extended Grunwald-Winstein equation has been applied to the solvolyses of two different systems, organo phosphorochloridates and cumyl p-nitrobenzoates, using the Nt scale of solvent nucleophilicity. Kinetic data are reported for the solvolyses of bis-4- (chlorophenyl) phosphorochloridate, N, N, N', N'-tetramethyl- diamidophosphorochloridate and cumyl p-nitrobenzoate, in several pure and mixed aqueous organic solvents. The phosphorochloridates were studied to determine if the Nt scale (developed for attack at a saturated carbon atom) could be applied to attack at phosphorous. Cumyl p- nitrobenzoate was studied to determine if there is nucleophilic solvent assistance present at the cationic transition state in the solvolysis. Results for the solvolyses of the phosphorochloridates indicate that N,N,N',N'-tetramethyldiamidophosphoro- chloridate correlates fairly well with the extended Grunwald-Winstein equation while bis-4-(chlorophenyl) phosphorochloridate does not. The latter compound gave results which were very similar to a related compound which was studied previously, diphenyl chlorophosphate; the two compounds have similar plots of log (k/kQ) versus 1NT + mYcli which show separate branches for each type of solvent system. In the extended Grunwald-Winstein equation, k is the specific rate of solvolysis in a particular solvent, ko is the specific rate of solvolysis in 80% ethanol, m is the sensitivity to the solvent ionizing power (Y) and 1. is the sensitivity to the solvent nucleophilicity (N). The m and 1. values are related to the amount of bond breaking and bond making respectively. The 1 and m values obtained for the compounds indicate that all three solvolyze via a bimolecular process. For the diamido compound, the large 1 (1.2) and large m (0.7) indicate that the compound may react by an addition-elimination type mechanism. The results for bis-4-(chlorophenyl) phosphorochloridate gave an 1 value of 1.02 and an m value of 0.10, indicating an SN2 reaction with bond making running ahead of bond breaking. The results previously obtained for diphenyl chlorophosphate suggest an Sn2 reaction with some addition-elimination also present. The analysis of the cumyl p-nitrobenzoate solvolysis showed that there is only a very modest nucleophilic component present, with a low 1 value of 0.13 and an m value of 0.95.

Comments

Includes bibliographical references (pages [95]-100)

Extent

viii, 100 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

Download

Share

COinS