A comparison between the sonochemical and thermal reaction of 5H,5Cl-Dibenz[a,d]cycloheptatriene with nitrobenzene

The reaction of 5H,5Cl-dibenzo[a,d]cycloheptatriene with nitrobenzene was investigated under both thermal (210°C) and ultrasonic (50°C, 40 kHz) activation. The reaction products of both procedures are similar, but their amounts depend on the activation source. To account for the products a common electron transfer reaction is postulated through the dibenzotropylium cation. The differences between the thermal and ultrasonic process is thought to arise from the role of nitrobenzene as oxidant. Under thermal conditions this occurs throughout the reaction mixture but under sonication it occurs only in the cavitation bubble and in its immediate vicinity.