Heterogeneous radical sonochemistry

Serpone, N. Colarusso, P. Sonochemistry I. Effects of ultrasounds on heterogeneous chemical reactions. A useful tool to generate radicals and to examine reaction mechanisms. Res. Chem. Intermed. 1994, 20, 635. 

From the empirical systematization of sonochemistry, it is sufficient to remember that, when the possibility exists, radical pathways are privileged at the expense of polar pathways, and sonochemical switching can result in a number of cases. In heterogeneous systems, reactions which follow ionic mechanisms are still sensitive to the mechanical effects of sonication. This "false sonochemistry" can, in principle, also be observed when efficient mixing techniques are applied, but the so-called simple mechanical effects are strongly dependent on geometrical factors and prove to be much more complicated than expected. 

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