Abstract
Sonochemiluminescence (SCL) from aqueous lucigenin (Luc^<2+>) solution is described in this study. It is found that strong SCL was observed from oxygen saturated alkaline solution containing small amount of Luc^<2+> when tripropylamine (TPA) was added as coreactant. A possible pathway for Luc^<2+> SCL reaction is discussed. In the ultrasonic field, TPA can adsorb onto the cavitation bubble/solution interface where TPA is oxidized by OH^. to form TPA^<.+> and subsequently produce a highly reducing TPA^. from the deprotonation reaction of the TPA^<.+>. TPA^. is suggested to initiate the reduction reactions of Luc^<2+> and O_2 and lead to the generation of Luc^<.+> and O_2^<.->, respectively. The radical-radical coupling reaction between Luc^<.+> and O_2^<.-> is expected to initiate the light emission.
