Non-Thermal Athermal Microwave Effects

Recently, Hajek and coworkers have reported results on microwave-assisted chemistry performed by cooling of a reaction mixture to as low as -176 °C. Reaction rates were recorded under microwave and conventional conditions. The higher reaction rates under microwave heating at sub-ambient temperatures were attributed to a superheating of the heterogeneous K10 catalyst [44], 

Another unusual phenomenon in microwave synthesis was described by Ley and coworkers. In several examples [45, 46], the authors found that pulsed microwave 

Microwave effects are still the subject of considerable current debate and controversy, and the reader should be aware that there is no agreement in the scientific community on the role that microwave effects play, not even on a definition of terms. 

401MD8 J. R. Woodward, R. J. Jackson, 

Diaz-Ortiz, E. Diez-Barra, Contemp. Org. Synth. 1997, 4, 373-386. 

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There is sfill some dispufe about how microwave irradiation accelerates reactions. Besides the generally accepted thermal effects, one beheves that there are some specific (but also thermal) microwave effects, such as the formation of hot spots . There is still some controversy about the existence of non-thermal (athermal) microwave effects. At the present time, new techniques such as coohng while heating are being investigated and the problem of upscahng... 

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