Supercritical fluids in the critical region as reaction media

2 Supercritical fluids in the critical region as reaction media 

Large variations in rate coefficients can occur in the region close to the critical point typically within a few degrees above the critical temperature and close 

1 Variation and enhancement of reaction rates. The unimolecular decomposition of a-chlorobenzyl methyl ether in 1,1-difluoroethane (Tc = 113.4°C) was studied by Johnston and coworkers [54], monitored in situ spectroscopically from the formation of benzaldehyde  

The mechanism is thought to be El [55], proceeding via a polar transition state complex  

The recombinations of chlorine atoms in molecular chlorine [57] and of iodine atoms in the system atomic iodine-molecular iodine-carbon dioxide [58] have been investigated under critical conditions. The concentration of the atomic species is not measured directly, but assumed to be directly proportional to the depression in the critical temperature of the reacting mixture, as ascertained from the disappearance of the liquid-vapour meniscus. 

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