Electron Scavenging in γ-Irradiated Liquid Methanol and Ethanol

Abstract

Articles you may be interested inOn the solvation of the trapped electron in γirradiated deuterated ethanol glass at 4 K Electron scavenging in liquid methanol and ethanol has been examined as a function of 14CHaBr and SF& concentration in the region from 10-5 to 0.3 M. The empirical scavenging model previously proposed for hydrocarbons can be successfully extended to alcohols if a competitive first-order reaction of the s?lvated free electron is included. Solvated free-electron and geminate-electron yields have been determmed to be 1.05 and 3.1. Analysis of the data from competitive experiments leads to an estimation of ~he absolute rate constants for reaction of solvated electrons with CHaBr, CHaC!, SF&, N.D, and acetone m methanol and ethanol and to an estimation of the half-life of the solvated free electrons in both solvents. The present results in ethanol can be correlated with the observations of Thomas and Bensasson on the nanosecond decay of solvated electrons in terms of an ion-pair lifetime distribution function similar to that applicable to hydrocarbon radiolysis.

Transient and Stable Silver Clusters Induced by Radiolysis in Methanol

“…18 The solvated electron yield corresponding to the free ion yield at 10 -7 -10 -6 s is G(e -solv ) ) 2 × 10 -7 mol J -1 . 20 The other main radiolytic species with reducing properties is the • CH 2 OH radical which is arising from isomerization of CH 3 O • , 10 and possibly also from dissociation of excited methanol molecules formed in reaction 3 or from reactions of the primary cation CH 3 17 biphenyl, 18 Cd 2+ , 18 and Ag + 6 and concern the electron yield. The radiolytic products resulting from oxidized radical and electron scavenging by triethylsilane R 3 SiH methanolic solutions were carefully analyzed and a mechanism for their formation proposed.…”

“…9 Silver ions released in the corrosion cascade (reactions 14-16) are adsorbed through reaction 18 and are also included in the development. This second cascade of reactions (eqs [17][18][19] corresponds to the delayed bleaching at 600 nm of the MV + blue color after 2 ms in the pulse radiolysis study (Figures 11 and inset b). The clusters now grow mostly by successive additions of supplementary reduced atoms (alternate reactions of electron transfer (eqs 17 and 19) and adsorption of surrounding metal ions (eq 18)), making the redox potential of Ag n + more and more favorable to the electron transfer.…”

The yield and extinction coefficient of the solvated electron in methanol: pulse radiolysis of nitrobenzene and tetranitromethane solutions

“…This expression may be rearranged to [8] A graph of [C6HsNO2]/kObs against 1/ [CH3-ONa] shown in Fig. 1 gives k, = (1.03 + 0.02) x lo9 M -~ s-' and K, = 3440 + 250.…”

“…O M) for Ar and N,O saturated solutions containing 8 x M C6H,N02 at 3.5 krad/ pulse. The large variation in yield (see Fig.…”

“…high radical concentration (spurs) to become homogeneously distributed in solution, vary from 1.0-2.0 (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14). Pulse radiolysis measurements of absorption spectra yield only the product GE,, ' thus uncertainty in G(e,-) results in a correponding uncertainty in the extinction 'G&(X), is the product in units of M-I cm-' of the radiation chemical yield and the molar decadic extinction coefficient of the light absorbing species, X, at wavelength h.…”