Reaction mechanisms residence time factors

Jarvis et used a hyperthermal nozzle with short residence times and low substrate concentrations, over a temperature range of 573—1623 K, to better explore the initial reaction steps of PPE decomposition, along with the corresponding steps in phenyl ethyl ether, in which homolysis of the C—O bond was less likely. They also completed CBS-QB3 calculations of the reaction pathways, ultimately concluding that the concerted reactions are likely at low temperatures and C—O bond-breaking pathways become a factor above 1273 K. Huang et al. completed a DFT study on 10 possible PPE decomposition pathways, two of which were concerted mechanisms and eight of which were free-radical mechanisms they saw that the concerted mechanisms were the preferred reaction channels and that these mechanisms overlapped with the retro-ene and MaccoU pathways explored previously. 

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