Mobility of geminate radical ions in concentrated alkane solutions as measured using electric field dependence of delayed fluorescence

Radiation Chemistry of Organic Liquids: Saturated Hydrocarbons

“…This study supports previous observation of rapid scavenging of cyclooctane holes by aromatic solutes in the initial stage of radiolysis [35]. Both in the squalane and cyclooctane, the natural lifetime of the high mobility solvent hole is less than 20 ns [24,[27][28][29][30][31][32][33][34][35]. It is still unclear whether this lifetime is limited by the inherent instability of the solvent holes or by their reactions with impurity.…”

“…Rapid scavenging reactions were also found to account for the anomalies in the magnetic field effect observed for delayed solute fluorescence induced by VUV excitation of squalane [32,33]. In cyclooctane, high-mobility solvent holes were observed using time-dependent electric-field-modulated delayed fluorescence [27] (with this technique, the electric field is used to sort the radical ions by their drift mobilities [34]). This study supports previous observation of rapid scavenging of cyclooctane holes by aromatic solutes in the initial stage of radiolysis [35].…”

“…Recently, high-mobility solvent holes were observed in 2,6,10,15,19,23-hexamethyltetracosane (squalane) [24] and in cyclooctane [27]. In the squalane, rapid electron-transfer reactions of solvent holes with low-IP solutes were observed using transient absorbance spectroscopy and magnetic resonance [24].…”

“…Perhaps, future work will reveal more examples of such short-lived high mobility holes. There is a recent suggestion of the presence of such holes in cyclopentane and cycloheptane; their natural lifetimes must be less than 5-10 ns [27]. Fasterthan-normal scavenging of short-lived isooctane holes by diphenylsulfide and biphenyl was observed using quantum beat [36] and transient absorption spectroscopy [20].…”

Picosecond pulse radiolysis: Dynamics of solvated electrons in ionic liquid and geminate ion recombination in liquid alkanes

“…The geminate ion recombination, as a most important primary process in radiation chemistry, has been studied for a long time by many researchers (Warman, 1982;Tagawa et al, 1983Tagawa et al, , 1989Yoshida et al, 1986;Borovkov et al, 2003Borovkov et al, , 2007. In regard to the kinetics of the geminate ion recombination, the geminate decay and the formation of excited states from the geminate ion recombination have been measured by using nanosecond and picosecond pulse radiolysis, and analyzed theoretically with the Smoluchowski equation based on the diffusion theory (Hong and Noolandi, 1978;Yoshida et al, 1984;Saeki et al, 2001).…”