CHEMILUMINESCENCE OF LANTANIDE IONS Ln<sup>(n – 1)+</sup> AT REDUCTIONOF Ln<sup>n+</sup> BY A SOLVATED ELECTRON
Using europium and cerium as an example, the ability of lanthanide ions to luminescence due to the chemical generation of electronically excited states of Ln<sup>(n</sup> <sup>‒ 1)+</sup> during the Ln<sup>n+</sup> reduction by a solvated electron was shown. The solvated electron was formed via electrons injection from a nonequilibrium plasma periodically generated in the moving bubble at ultrasonic vibrations. A key reaction of the detected single-bubble sonochemiluminescence (SCL) is the Eu<sup>3+</sup> and Ce<sup>4+</sup> reduction to a divalent and trivalent state, respectively, by a solvated (in water and ethylene glycol) electron. It was established that the SCL emitters are excited ions *Eu<sup>2+</sup> и *Ce<sup>3+</sup>, which, along with luminescence, have high reducing properties (redox potential from –2.9 V). The latter factor determines the possibility of using ultrasonic generation of *Eu<sup>2+</sup> и *Ce<sup>3+</sup> in numerous reactions of organic synthesis and metal complex catalysis.