Premium
The kinetics and mechanisms of the gas‐phase pyrolysis of ethyl 4‐bromobutyrate. The ion‐pair mechanism revisited
Author(s) -
Chuchani Gabriel,
Dominguez Rosa M.
Publication year - 1983
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/kin.550150808
Subject(s) - chemistry , arrhenius equation , pyrolysis , substituent , kinetics , torr , reaction rate constant , atmospheric temperature range , gas phase , ion , rate equation , elimination reaction , reaction mechanism , computational chemistry , thermodynamics , medicinal chemistry , organic chemistry , activation energy , catalysis , physics , quantum mechanics
The gas‐phase pyrolysis of ethyl 4‐bromobutyrate has been investigated in a static system over the temperature range of 354.6–374.7°C and the pressure range of 51–126 torr. The elimination reaction in seasoned vessels and in the presence of at least twofold of a chain radical inhibitor is homogeneous, unimolecular, and obeys a first‐order rate law. The rate coefficients are given by the Arrhenius equation log k 1 (s −1 ) = (13.31 ± 0.82) – (205.1 ± 8.6)kJ/mol/2.303 RT . The partial rates for the parallel eliminations to normal dehydrobromination, lactone formation, and bromobutyric acid product have been estimated and reported. The carboethoxy substituent of the bromoester has been found to assist anchimerically the elimination process, where dihydrobromination and lactone formation arise from an intimate ion‐pair mechanism.