2004 年 14 巻 1 号 p. 12-19
In this article, recent advances in the measurement of the translational diffusion of the reaction intermediate radicals are reviewed. It was described how the diffusion of the reaction intermediates of short lifetimes were measured by the transient grating spectroscopy in supercritical fluids (SCFs). Transient ketyl radicals produced by the hydrogen abstraction reaction shows a relatively slower diffusion than that of the stable molecules of similar size in SCF. The relation of the slowness of the diffusion to the local density enhancement is discussed.