Na. Alawadi et al., GAS-PHASE KINETICS OF ELIMINATION-REACTIONS OF PENTANE-2,4-DIONE DERIVATIVES, International journal of chemical kinetics, 27(5), 1995, pp. 517-523
Gas-phase elimination reactions of pentane-2,4-dione, methyl acetoacet
ate, ethyl acetoacetate, 3-phenylhydroazopentane-2,4-dione, and ethyl
3-oxo-2-phenyl-hydrazonobutyrate have been measured in the temperature
ranges of 744-783, 662-695, 614-663, 604-664, and 503-555 K, respecti
vely, using a flow-thermolysis technique. These compounds undergo unim
olecular first-order elimination reactions, for which log A = 11.9, 11
.2, 11.7, 11.5, and 11.7 s(-1) and E(a) = 198.3, 167.1, 141.7, 165.6,
and 141.7 kJ mol(-1), respectively. The kinetic data and product analy
sis shows that the reactions are highly affected by the electronic nat
ure of the substituents at the carbonyl and methylene carbon atoms of
the substrates investigated. (C) 1995 John Wiley & Sons, Inc.