A study of the kinetic and thermodynamic properties of carbon acids in methanol
The thermodynamic acidity (pKa) of iodoform in methanol was determined at 25°C and 35°C; the values are 18.74 and 18.05, respectively . These acidity constants were determined by a modification of the equilibrium quenching technique which involves the conversion of the conjugate base of iodoform,...
Main Author: | |
---|---|
Format: | Text |
Language: | unknown |
Published: |
Scholars' Mine
1974
|
Subjects: | |
Online Access: | https://scholarsmine.mst.edu/doctoral_dissertations/297 https://scholarsmine.mst.edu/context/doctoral_dissertations/article/1299/viewcontent/Filger_Dennis_1974.pdf |
id |
ftmissouriunivst:oai:scholarsmine.mst.edu:doctoral_dissertations-1299 |
---|---|
record_format |
openpolar |
spelling |
ftmissouriunivst:oai:scholarsmine.mst.edu:doctoral_dissertations-1299 2024-09-15T18:01:42+00:00 A study of the kinetic and thermodynamic properties of carbon acids in methanol Filger, Dennis L. 1974-01-01T08:00:00Z application/pdf https://scholarsmine.mst.edu/doctoral_dissertations/297 https://scholarsmine.mst.edu/context/doctoral_dissertations/article/1299/viewcontent/Filger_Dennis_1974.pdf unknown Scholars' Mine https://scholarsmine.mst.edu/doctoral_dissertations/297 https://scholarsmine.mst.edu/context/doctoral_dissertations/article/1299/viewcontent/Filger_Dennis_1974.pdf © 1974 Dennis Lee Filger, All rights reserved. Doctoral Dissertations Iodoform Carbonic acid Thermochemistry Chemistry text 1974 ftmissouriunivst 2024-08-02T04:27:33Z The thermodynamic acidity (pKa) of iodoform in methanol was determined at 25°C and 35°C; the values are 18.74 and 18.05, respectively . These acidity constants were determined by a modification of the equilibrium quenching technique which involves the conversion of the conjugate base of iodoform, present at equilibrium, to the radioactively labelled acid. The rate constants for the methoxide-catalyzed hydrogentritium exchange of chloroform, iodoform, 9-phenylfluorene and indene were determined in methanol at various temperatures. The second-order rate constants obtained from these studies were shown to be the rate constants for removal of a triton. The activation parameters (ΔH‡ and ΔS‡) for the exchange reactions were also determined for these hydrocarbons from the results of the exchange studies at various temperatures. The hydrogen-deuterium isotope effects for the reaction of chloroform, iodoform or 9-phenylfluorene with methoxide were determined in methanol at various temperatures. These isotope effects were found to be small for chloroform and iodoform (1.25 and 1.02 at 0°C, respectively), and large for 9-phenylfluorene (5 .3 at 10°C). The low isotope effects for the haloforms are suggested as evidence of a highly asymmetric transition state for the proton transfer. A method was developed to determine the hydrogen-tritium isotope effects for the reaction of methanol with the conjugate bases of chloroform, iodoform and 9-phenylfluorene in methanol at bases of chloroform, iodoform and 9-phenylfluorene in methanol at various temperatures. The values for these isotope effects at 0°C are 1.50 and 1.27 for the chloroform and iodoform conjugate bases, respectively and 12.9 for the conjugate base of 9-phenylfluorene at 10°C. From the results of the kinetic exchange studies on iodoform and chloroform, along with the thermodynamic pKa's determined for iodoform, and assuming a Bronsted exponent of unity, the pKa of chloroform in methanol at 25°C was calculated to be 21.1"--Abstract, pages iii-iv. Text Carbonic acid Missouri University of Science and Technology (Missouri S&T): Scholars' Mine |
institution |
Open Polar |
collection |
Missouri University of Science and Technology (Missouri S&T): Scholars' Mine |
op_collection_id |
ftmissouriunivst |
language |
unknown |
topic |
Iodoform Carbonic acid Thermochemistry Chemistry |
spellingShingle |
Iodoform Carbonic acid Thermochemistry Chemistry Filger, Dennis L. A study of the kinetic and thermodynamic properties of carbon acids in methanol |
topic_facet |
Iodoform Carbonic acid Thermochemistry Chemistry |
description |
The thermodynamic acidity (pKa) of iodoform in methanol was determined at 25°C and 35°C; the values are 18.74 and 18.05, respectively . These acidity constants were determined by a modification of the equilibrium quenching technique which involves the conversion of the conjugate base of iodoform, present at equilibrium, to the radioactively labelled acid. The rate constants for the methoxide-catalyzed hydrogentritium exchange of chloroform, iodoform, 9-phenylfluorene and indene were determined in methanol at various temperatures. The second-order rate constants obtained from these studies were shown to be the rate constants for removal of a triton. The activation parameters (ΔH‡ and ΔS‡) for the exchange reactions were also determined for these hydrocarbons from the results of the exchange studies at various temperatures. The hydrogen-deuterium isotope effects for the reaction of chloroform, iodoform or 9-phenylfluorene with methoxide were determined in methanol at various temperatures. These isotope effects were found to be small for chloroform and iodoform (1.25 and 1.02 at 0°C, respectively), and large for 9-phenylfluorene (5 .3 at 10°C). The low isotope effects for the haloforms are suggested as evidence of a highly asymmetric transition state for the proton transfer. A method was developed to determine the hydrogen-tritium isotope effects for the reaction of methanol with the conjugate bases of chloroform, iodoform and 9-phenylfluorene in methanol at bases of chloroform, iodoform and 9-phenylfluorene in methanol at various temperatures. The values for these isotope effects at 0°C are 1.50 and 1.27 for the chloroform and iodoform conjugate bases, respectively and 12.9 for the conjugate base of 9-phenylfluorene at 10°C. From the results of the kinetic exchange studies on iodoform and chloroform, along with the thermodynamic pKa's determined for iodoform, and assuming a Bronsted exponent of unity, the pKa of chloroform in methanol at 25°C was calculated to be 21.1"--Abstract, pages iii-iv. |
format |
Text |
author |
Filger, Dennis L. |
author_facet |
Filger, Dennis L. |
author_sort |
Filger, Dennis L. |
title |
A study of the kinetic and thermodynamic properties of carbon acids in methanol |
title_short |
A study of the kinetic and thermodynamic properties of carbon acids in methanol |
title_full |
A study of the kinetic and thermodynamic properties of carbon acids in methanol |
title_fullStr |
A study of the kinetic and thermodynamic properties of carbon acids in methanol |
title_full_unstemmed |
A study of the kinetic and thermodynamic properties of carbon acids in methanol |
title_sort |
study of the kinetic and thermodynamic properties of carbon acids in methanol |
publisher |
Scholars' Mine |
publishDate |
1974 |
url |
https://scholarsmine.mst.edu/doctoral_dissertations/297 https://scholarsmine.mst.edu/context/doctoral_dissertations/article/1299/viewcontent/Filger_Dennis_1974.pdf |
genre |
Carbonic acid |
genre_facet |
Carbonic acid |
op_source |
Doctoral Dissertations |
op_relation |
https://scholarsmine.mst.edu/doctoral_dissertations/297 https://scholarsmine.mst.edu/context/doctoral_dissertations/article/1299/viewcontent/Filger_Dennis_1974.pdf |
op_rights |
© 1974 Dennis Lee Filger, All rights reserved. |
_version_ |
1810438788795596800 |