Sonochemiluminescence of Ru(bpy)33+ in aqueous solutions. Evidence of the formation of hydrated electrons during the single-bubble sonolysis in a neutral aqueous medium

New sonochemiluminescence involving solvated electron in Ce(III)/Ce(IV) solutions

“…For example, in aqueous solutions of ruthenium(III)-bipyridyl complex, the excited MLCT state of the Ru(bpy) 3 2+ (*Ru(bpy) 3 2+ ) emerges directly in the elementary act of reduction upon transferring electron to the ligand-centered orbital unoccupied in the initial Ru(bpy) 3 3+ complex. This luminescent reaction confirmed the electron ejection from the plasma of the bubble and previously unknown generation of the hydrated electrons ( e aq ) during moving single-bubble sonolysis of water (1) : besides the processes involving other primary products of the sonolysis (2) [7] : …”

“…Thus, moving SBSL of Ce 3+ in the aqueous solutions of inorganic salt CeCl 3 has three mechanisms in contrast to SBSL having only the SPL mechanism. These are SCL at Ce 3+ concentrations less than 10 –4 M, SCL + SPL in the concentration range of 10 –4 –10 –2 M, and SCL + SPL + CE at [Ce 3+ ] > 10 –2 M. The multibubble sonoluminescence of cerium ions, despite its apparent similarity to moving SBSL, represents only SPL at [Ce 3+ ] = 10 –4 –10 –2 M and, apparently, SPL + CE at large concentrations due to absence of e aq among the primary products of water decomposition in this mode of sonolysis [7] , [31] , [32] and accordingly SCL.…”

“…Such SCL is known for many systems, e.g. aqueous solutions of luminol [3] , acridinium NHS ester [4] , chelated Tb 3+ , Ru(bpy) 3 2+ , Ru(bpy) 3 3+ complexes [5] , [6] , [7] and non-aqueous solutions of various organic compounds [8] , [9] , [10] . Among them, a particular attention is paid to the systems whereby chemiluminescence (CL) arises in the reactions involving the sonolytically generated solvated electron ( e s ).…”

Two-phase dual-signal-readout immunosensing platform based on multifunctional carbon nano-onions for ovarian cancer biomarker detection

“…At the same time of SL generation, the internal pressure of the bubbles can generate a local high temperature (''hot spots'') and tremendous pressure, 7 leading to the ionization of water molecules and the generation of free radicals. 8,9 Secondly, sonochemiluminescence is generated by the reaction of free radicals produced by sonochemistry with a luminophore. 10 Accordingly, the SCL signal generated via excitation of the acoustic cavitation effect offers great potential for sensor applications.…”

Computational simulation of ionization processes in single-bubble and multi-bubble sonoluminescence

“…[14] Further, the products of the chemical reaction are ejected into the solution from the bubble and may generate subsequent new products, which may affect the characteristics of the spectrum obtained from sonoluminescence (SL), [5,9] sonochemiluminescence (SCL), [15] and sonophotoluminescence (SPL). [16,17] Recently, Sharipov et al reported the possibility of hydrated electrons (e − aq ) generation upon sonolysis of water in SBSL and the absence of e − aq in MBSL after they studied the spectra of SBSL and MBSL in solutions of Ru(bpy) 2+ 3 [18] and Ce(III)/Ce(IV). [19] In addition, they confirmed the formation of e − aq during the moving SBSL (MSBSL) by the activation of Tb(III) ion sonoluminescence owing to e − aq acceptors in aqueous solution, whereas e − aq is absent in MBSL in the same solution.…”