Mechanistic and synthetic aspects of the anodic oxidation of hydrocarbons
Mechanistic and synthetic aspects of the anodic oxidation of hydrocarbons
The mechanism of the first anodic wave oxidation of a series ofmethylbenzenes in dry acetonitrile is discussed. Several electrochemical techniques were used to differentiate between the mechanism of oxidation of mesitylene and that of durene and hexamethylbenzene. Modulated Specular Reflectance Spectroscopy identified the unstable dimer cation radical intermediate during mesitylene oxidation, in addition to the carbonium ion intermediate observed for all three methylbenzenes.. The rotating disc electrode showed one-electron behaviour for mesitylene at high rotation rate while durene and hexamethylbenzene showed two-electron behaviour at all rotation speeds. The nitrilium ion was identified asthe stable product from the oxidation of hexamethylbenzene in dry acetonitrile. An e.c.e. mechanism was proposed for the oxidation of all three methylbenzenes.In addition to the initial oxidation process, further anodic waves at higher potentials were observed for methylbenzenes: the number of irreversible oxidation waves observed in dry acetonitrile for either dureneor hexamethylbenzene equalled the number of methyl substituents. For the second wave oxidation of hexamethylbenzene in dry acetonitrile, an unstable dicarbonium or carbonium-nitrilium ion was formed which reacted with acetonitrile to form a stable dinitrilium ion: 1,3-(2,4,5,6-tetramethyl)bisacetamidomethylbenzene was formed upon quenching with water. The behaviour of durene was essentially the same. Adamantane and several other saturated hydrocarbons also showed a series of irreversible anodic waves during voltammetry in both acetonitrile and trifluoroacetic acid-trifluoroacetic anhydride(5%). Monosubstitution occurred in the first wave and disubstitution occurred in the second wave. Competitive substitution/fragmentation of substituted adamantanes is discussed, as well as the mechanistic and synthetic aspects of the adamantane disubstitution reaction: the electrochemical conversion of monofunctionalised adamantanes to difunctionalised adamantanes is also.
University of Southampton
1976
Edwards, Gary James
(1976)
Mechanistic and synthetic aspects of the anodic oxidation of hydrocarbons.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
The mechanism of the first anodic wave oxidation of a series ofmethylbenzenes in dry acetonitrile is discussed. Several electrochemical techniques were used to differentiate between the mechanism of oxidation of mesitylene and that of durene and hexamethylbenzene. Modulated Specular Reflectance Spectroscopy identified the unstable dimer cation radical intermediate during mesitylene oxidation, in addition to the carbonium ion intermediate observed for all three methylbenzenes.. The rotating disc electrode showed one-electron behaviour for mesitylene at high rotation rate while durene and hexamethylbenzene showed two-electron behaviour at all rotation speeds. The nitrilium ion was identified asthe stable product from the oxidation of hexamethylbenzene in dry acetonitrile. An e.c.e. mechanism was proposed for the oxidation of all three methylbenzenes.In addition to the initial oxidation process, further anodic waves at higher potentials were observed for methylbenzenes: the number of irreversible oxidation waves observed in dry acetonitrile for either dureneor hexamethylbenzene equalled the number of methyl substituents. For the second wave oxidation of hexamethylbenzene in dry acetonitrile, an unstable dicarbonium or carbonium-nitrilium ion was formed which reacted with acetonitrile to form a stable dinitrilium ion: 1,3-(2,4,5,6-tetramethyl)bisacetamidomethylbenzene was formed upon quenching with water. The behaviour of durene was essentially the same. Adamantane and several other saturated hydrocarbons also showed a series of irreversible anodic waves during voltammetry in both acetonitrile and trifluoroacetic acid-trifluoroacetic anhydride(5%). Monosubstitution occurred in the first wave and disubstitution occurred in the second wave. Competitive substitution/fragmentation of substituted adamantanes is discussed, as well as the mechanistic and synthetic aspects of the adamantane disubstitution reaction: the electrochemical conversion of monofunctionalised adamantanes to difunctionalised adamantanes is also.
This record has no associated files available for download.
More information
Published date: 1976
Identifiers
Local EPrints ID: 462538
URI: http://eprints.soton.ac.uk/id/eprint/462538
PURE UUID: c782007d-b279-42e6-98c9-e199c3c3bde8
Catalogue record
Date deposited: 04 Jul 2022 19:16
Last modified: 04 Jul 2022 19:16
Export record
Contributors
Author:
Gary James Edwards
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics