Abstract:
Photographs and spectra of single-bubble sonoluminescence of a bubble moving in pure water and aqueous solutions of Ru(bpy)$_{3}^{2+}$ are obtained. It is shown for ruthenium complex solutions that there are luminescence regions outside the main trajectory of motion of the luminous bubble, which are absent in pure water. The observed spatial localization of these regions confirms that (as we have shown previously) they are caused by sonochemiluminescence of the ruthenium complex in the solution bulk that is secondary relative to the primary sonoluminescence of the bubble.