Effects Depending on Reaction Mechanisms

The effects of MW result from material-wave interactions and, because of the dipolar polarization phenomenon, the greater the polarity of a molecule (for example the solvent) the more pronounced the MW effect when temperature is increased 

Specific microwave effects can be expected fior polar mechanisms, when the polarity is increased during the reaction from the ground state to the transition state (as more or less implied by Abramovich in the conclusion of his review in 1991 [66]). The outcome essentially depends on the medium and the reaction mechanism. If stabilization of the transition state (TS) is more effective than stabilization of the ground state (GS), the result is enhancement of reactivity by reduction of the activation energy (Fig. 4.3), because of dipole-dipole type electrostatic interactions of polar molecules with the electric field. 

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Effects Depending on Reaction Mechanisms 147 Tab. 4.S. Results from the phenacylation of 1,2,4-triazole. 

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