Matches in SemOpenAlex for { <https://semopenalex.org/work/W2006197856> ?p ?o ?g. }
Showing items 1 to 62 of
62
with 100 items per page.
- W2006197856 endingPage "89" @default.
- W2006197856 startingPage "89" @default.
- W2006197856 abstract "In the gas phase, diacetamide undergoes unimolecular first-order elimination to give keten and acetamide with log A 12.42 s–1 and Ea 158.23 kJ mol–1 so that the reaction proceeds via a cyclic six-membered transition state. At 600 K the reaction is 6.7-fold slower than the comparable pyrolysis of acetic anhydride, but 4.4-fold faster than pyrolysis of diacetyl sulphide. This shows that in contrast to ester pyrolysis, heterolysis of the Cα–X bond in these compounds is relatively unimportant, the major rate-determining step being nucleophilic attack of the carbonyl group upon the β-hydrogen; the nucleophilicity of this carbonyl group is probably enhanced by resonance with the lone pair of the group X. The very high reactivity of the diacetyl compounds relative to their ester equivalents suggests that they pyrolyse via the enol forms. Pyrolysis of diacetyl sulphide is accompanied by first-order decomposition of thioacetic acid (one of the primary reaction products) by a number of pathways which give rise to keten, hydrogen sulphide, carbon oxysulphide, methanethiol, and methyl thioacetate, the latter probably arising from a combination of methanethiol with unchanged thioacetic acid which also accounts for the low stoicheiometry (1.8) of the reaction. The rate of elimination of thioacetic acid is governed by the parameters log A 12.5 s–1 and Ea 175.7 kJ mol–1; slightly different values are obtained from the acid produced by decomposition of diacetyl sulphide viz. 12.5 and 173.1, respectively, probably due to the differing initial proportions of the thiono- and thiolo-forms. Decomposition is much faster than the corresponding reactions of acetic acid and diacetamide, probably because the nucleophilicity of the thiol group is not lowered by resonance to the extent that operates for the corresponding nucleophiles in acetic acid and acetamide. 2-Acetoxypyridine also undergoes thermal elimination to 2-pyridone and keten, but satisfactory kinetics could not be obtained, due possibly to surface effects and an equilibrium between the N-acetyl and O-acetyl tautomers. The bulk of the compound is much more stable than diacetamide because it exists largely in the O-acetyl form." @default.
- W2006197856 created "2016-06-24" @default.
- W2006197856 creator A5063514521 @default.
- W2006197856 date "1983-01-01" @default.
- W2006197856 modified "2023-09-26" @default.
- W2006197856 title "The mechanism of thermal elimination. Part 14. Pyrolysis of diacetamide, 2-acetoxypyridine, diacetyl sulphide, and thioacetic acid: possible involvement of enol forms in gas-phase eliminations" @default.
- W2006197856 doi "https://doi.org/10.1039/p29830000089" @default.
- W2006197856 hasPublicationYear "1983" @default.
- W2006197856 type Work @default.
- W2006197856 sameAs 2006197856 @default.
- W2006197856 citedByCount "5" @default.
- W2006197856 countsByYear W20061978562019 @default.
- W2006197856 crossrefType "journal-article" @default.
- W2006197856 hasAuthorship W2006197856A5063514521 @default.
- W2006197856 hasConcept C155647269 @default.
- W2006197856 hasConcept C160434732 @default.
- W2006197856 hasConcept C161790260 @default.
- W2006197856 hasConcept C178790620 @default.
- W2006197856 hasConcept C178907741 @default.
- W2006197856 hasConcept C185592680 @default.
- W2006197856 hasConcept C2776353806 @default.
- W2006197856 hasConcept C2776673659 @default.
- W2006197856 hasConcept C2777495281 @default.
- W2006197856 hasConcept C2778874822 @default.
- W2006197856 hasConcept C2779529559 @default.
- W2006197856 hasConcept C36759035 @default.
- W2006197856 hasConcept C518881349 @default.
- W2006197856 hasConcept C75473681 @default.
- W2006197856 hasConceptScore W2006197856C155647269 @default.
- W2006197856 hasConceptScore W2006197856C160434732 @default.
- W2006197856 hasConceptScore W2006197856C161790260 @default.
- W2006197856 hasConceptScore W2006197856C178790620 @default.
- W2006197856 hasConceptScore W2006197856C178907741 @default.
- W2006197856 hasConceptScore W2006197856C185592680 @default.
- W2006197856 hasConceptScore W2006197856C2776353806 @default.
- W2006197856 hasConceptScore W2006197856C2776673659 @default.
- W2006197856 hasConceptScore W2006197856C2777495281 @default.
- W2006197856 hasConceptScore W2006197856C2778874822 @default.
- W2006197856 hasConceptScore W2006197856C2779529559 @default.
- W2006197856 hasConceptScore W2006197856C36759035 @default.
- W2006197856 hasConceptScore W2006197856C518881349 @default.
- W2006197856 hasConceptScore W2006197856C75473681 @default.
- W2006197856 hasIssue "2" @default.
- W2006197856 hasLocation W20061978561 @default.
- W2006197856 hasOpenAccess W2006197856 @default.
- W2006197856 hasPrimaryLocation W20061978561 @default.
- W2006197856 hasRelatedWork W1971585469 @default.
- W2006197856 hasRelatedWork W1975996446 @default.
- W2006197856 hasRelatedWork W1985676835 @default.
- W2006197856 hasRelatedWork W2005384896 @default.
- W2006197856 hasRelatedWork W2051265226 @default.
- W2006197856 hasRelatedWork W2098235972 @default.
- W2006197856 hasRelatedWork W2099596618 @default.
- W2006197856 hasRelatedWork W2141444166 @default.
- W2006197856 hasRelatedWork W2951366851 @default.
- W2006197856 hasRelatedWork W2997368340 @default.
- W2006197856 isParatext "false" @default.
- W2006197856 isRetracted "false" @default.
- W2006197856 magId "2006197856" @default.
- W2006197856 workType "article" @default.