ORGANIC SONOELECTROCHEMISTRY - REDUCTION OF FLUORESCEIN IN THE PRESENCE OF 20 KHZ POWER ULTRASOUND - AN EC' REACTION

The electro-reduction of the dye fluorescein at mercury electrodes in basic aqueous solution is known to produce the stable semi-fluorescein radical. When the electrolysis is exposed to power ultrasound of intensity up to ca. 65 W cm-2 the radicals are shown to be re-oxidised by means of hydroxyl radicals formed through the sonochemical decomposition of the aqueous solvent. The electrode process adopts the mechanistic characteristics of a 'sono-EC′' or 'sono-catalytic' reaction and this constitutes, to the author's knowledge, the first ever mechanistic assignment of this type