Conductimetric study of the kinetics of electrons in pulse irradiated n-hexane and cyclohexane at room temperature

Abstract

Measurements of the ion current following an electron pulse have given values of k r / p (where k, is the ion recombination rate constant and p the electron mobility) and G p (extrapolated to zero field) of 1 .OO( & 0.08) x cm2 V-' respectively for n-hexane, and 0.91( k 0.07) x loe6 V cm and 5.0( k 0.3) x lo-* cm2 V-' for cyclohexane. For n-hexane these and results obtained optically are consistent with kr = 6( +_ 1) x loz3 dm3 mol-I s-l, G = 0.13 and p = 0.09 cm2 V-' s-'. Using p = 0.35 cm2 V-' for cyclohexane, kr = 1.93(+0.14) x 1014 dm3 mol-I S-l.

Electron Trapping by Polar Molecules in Alkane Liquids: Cluster Chemistry in Dilute Solution

“…44 Consequently, the yield of free solvated electrons is low (ca. 0.13 per 100 eV), and since their molar absorptivity ( ε 1000 ≈ 8,300 M -1 cm -1 ) 24,45 concentration of (free!) electrons at the end of the electron pulse was ca.…”

“…Hereafter, electron "trapping" or "attachment" refers to the formation of a e S n solv Mozumder's paper 18 outlining this scenario stimulated a brief flurry of experimental activity. [19][20][21][22][23][24][25][26][27] It was expected that small electron clusters, as opposed to solvated electrons in neat liquids, would be simple to study and to model. (Similar expectations were later nurtured for gas phase cluster anions).…”

“…(Similar expectations were later nurtured for gas phase cluster anions). Electron localization in dilute solutions of water and alcohols in liquid [19][20][21][22][23][24][25][26] and vitreous e.g., 27 alkanes was studied using pulse radiolysis -transient absorbance (TA) spectroscopy, 19,20,23,24,27 time-resolved conductivity, [21][22][23][24][25] and optically detected magnetic resonance (ODMR). 26 The results obtained in these studies hinted at a complex picture of electron dynamics and the interest in mixed solvents quickly waned.…”

“…19 In fact, this reaction has not been observed even on a longer time scale. [20][21][22][23][24][25] The only observation of a cluster-growth reaction similar to reaction (5) is by Ahmad et al 22 who observed, albeit indirectly, slow (ca. 7x10 9 M -1 s -1 ) complexation of methanol with the tentative water tetramer in isooctane.…”

Excess electron kinetics by dispersive conductivity: A proposition

“…Here the majority of electrons are known to be localized (Schiller, 1972;Davis and Brown, 1975;Holroyd, 1987;Nyikos and Schiller, 1988;Schmidt, 1997). Electron mobility is about m ffi 10 À5 m 2 =Vs hence with s % 4 Â 10 À10 m (this being the radius of a bubble around the localized electron) one finds t D % 10 À13 s. The second order scavenging rate coefficient, k 0 s is in the order of k 0 s % 10 12 M À1 s À1 for scavengers like N 2 O, pyrene, SF 6 or CCl 4 (Baxendale et al, 1973;Allen and Holroyd, 1974;Allen et al, 1975, see also Schiller and Nyikos, 1977). Thus with a scavenger concentration of about 1 M one finds Z % 0:9 by Eq.…”