Pulse Radiolysis of Liquid Methylamine, Ethylamine, and Ammonia: The Yield of Solvated Electrons

1974 ◽  
Vol 52 (18) ◽  
pp. 3269-3273 ◽  
Author(s):  
William Arthur Seddon ◽  
John Wallace Fletcher ◽  
Fred Charles Sopchyshyn ◽  
John Jevcak
Keyword(s):  
Pulse Radiolysis ◽  
Basic Solution ◽  
Solvated Electrons

Yields of solvated electrons, [Formula: see text], have been measured in both the pure and basic solvents using biphenyl and pyrene as electron scavengers. In pure methylamine and ethylamine [Formula: see text]and 1.84 ± 0.1, respectively. However in basic solution these yields more than double giving [Formula: see text]. In liquid NH3 and ND3 at −15 °C, [Formula: see text] and 3.6 ± 0.2, respectively. The latter yields seem independent of base and temperature from −15 to −50 °C. Comparisons with previous work are discussed.

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

1977 ◽  
Vol 55 (11) ◽  
pp. 2030-2043 ◽  
Author(s):  
David W. Johnson ◽  
G. Arthur Salmon
Keyword(s):  
Pulse Radiolysis ◽  
Optical Pulse ◽  
Basic Solution ◽  
Solvated Electron ◽  
Solvated Electrons ◽  
Extinction Coefficients ◽  
Hydroxymethyl Radical ◽  
Direct Measurements ◽  
Wide Range ◽  
Basic Solutions

The radical anion [Formula: see text] NB−, which has a strong absorption spectrum from 250–500 nm, is formed by reaction of nitrobenzene with solvated electrons, es−, and hydroxymethyl radical anions, •CO2O−, with k1 = (1.92 ± 0.35) × 1010 M−1 s−1 and k2 = (1.03 ± 0.02) × 1010 M−1 s−1.[Formula: see text]Gελ is constant for NB− over a wide range of nitrobenzene concentrations in basic solution. By assuming that the yields of scavengeable radicals are the same in neutral and basic solutions we obtain ε(NB−)300 nm = (1.66 ± 0.02) × 104 M−1 cm−1. This value is used to evaluate the yield of es− scavengeable by dilute solutions of solutes as G(es−)esc = 1.20 ± 0.03. Extinction coefficients of es−, hydroxymethyl radicals, •CH2OH, and •CO2O− and the oscillator strength of the es− absorption are calculated.The yields of es− determined by previous workers are discussed in terms of dry, damp, geminate, free, spur, and escaped electrons. A model is constructed in terms of damp, spur, and escaped electrons which compares favourably with experimental scavenging results and direct measurements by optical pulse radiolysis.

Yield and properties of solvated electrons created by the γ radiolysis of hexamethylphosphorotriamide

1977 ◽  
Vol 55 (11) ◽  
pp. 1832-1835 ◽  
Author(s):  
M. C. Lebas ◽  
J. Sutton ◽  
A. M. Koulkes-Pujo
Keyword(s):  
Pulse Radiolysis ◽  
Total Yield ◽  
Solvated Electron ◽  
Solvated Electrons ◽  
Γ Rays

According to various authors, the value of the yield of the solvated electron in the pulse radiolysis of hexamethylphosphorotriamide (HMPT) varies from 1.2 to 2.4 and increases to 4.2 or 3.1 in the presence of NaBr. We exposed this compound to γ rays after purification and saturation with N2O. N2 was formed with a yield G(N2) = 4.4 ± 0.4. After elimination of a certain number of processes which might also lead to N2 formation, it was concluded that this G(N2) corresponds to the total yield of electrons. This value was confirmed by measuring G(Br−) obtained by radiolysis of HMPT with p-bromophenol as a scavenger. The yield of N2 remains constant whenever solutes generally known as good electron scavengers are added (H+, CH3COCH3, NO3−). An interpretation of the results leads to the suggestion of the formation of a dielectron in this medium.

Pulse radiolysis observations of solvated electrons in liquid hydrocarbons

1971 ◽  
Vol 12 (2) ◽  
pp. 347-348 ◽  
Author(s):  
J.H. Baxendale ◽  
C. Bell ◽  
P. Wardman
Keyword(s):  
Pulse Radiolysis ◽  
Liquid Hydrocarbons ◽  
Solvated Electrons

A pulse radiolysis study of solvated electrons in tert-butanol/water solutions

1986 ◽  
Vol 64 (8) ◽  
pp. 1548-1552
Author(s):  
Joanna Cygler ◽  
Norman V. Klassen ◽  
Carl K. Ross
Keyword(s):  
Experimental Data ◽  
Pulse Radiolysis ◽  
Oh Radicals ◽  
Solvated Electrons ◽  
Secondary Electrons ◽  
Water Solutions ◽  
Tert Butanol

Many solutes, added to water in amounts of a few mol%, cause an increase in the yield of solvated electrons (es−) measured by pulse radiolysis. A pulse radiolysis study of tert-butanol (tBuOH) in D2O has been carried out to investigate this phenomenon. Detailed measurements of the yield, measured as Gεmax(es−), and the deeay of solvated electrons were made at 6, 25, and 46 °C over the range 0–5mol% tBuOH. The maximum Gεmax(es−) occurs at about 1 mol% tBuOH, but the exact concentration depends on the temperature of the sample and the time after the pulse at which the measurement is made. Three factors are examined as contributing to the increased Gεmax(es−) in the presence of tBuOH and certain other solutes. They are (i) the change in viscosity produced by the added solute, (ii) the scavenging of OH radicals by the solute, thereby reducing the reaction of OH with es− and (iii) the possibility that the addition of the solute leads to an increase in the thermalization distance of the secondary electrons. It is concluded that effects (i) and (ii) are sufficient to explain the existing experimental data.

The Pulse Radiolysis of Dimethylsulfoxide and Binary Mixtures with Water

1973 ◽  
Vol 51 (13) ◽  
pp. 2195-2206 ◽  
Author(s):  
T. K. Cooper ◽  
D. C. Walker ◽  
H. A. Gillis ◽  
N. V. Klassen
Keyword(s):  
Dielectric Constant ◽  
Optical Properties ◽  
Absorption Band ◽  
Linear Relationship ◽  
Half Life ◽  
Pulse Radiolysis ◽  
Water Molecules ◽  
Solvated Electrons ◽  
Free Ion ◽  
Pure Dmso

The simultaneous interaction of solvated electrons with strongly solvating water molecules and weakly solvating dimethylsulfoxide (DMSO) molecules has been studied by pulse radiolysis. In all DMSO/H2O mixtures investigated the solvated electrons have a single absorption band with a maximum intermediate between that of pure DMSO (λmax > 1500 nm) and that of water (λmax = 720 nm). There is a nearly linear relationship between the photon energy of λmax and the bulk dielectric constant, indicating that the optical properties of solvated electrons in the mixtures are not dominated by the water. A minimum is observed in the variation of Gεmax with DMSO/H2O composition which may be associated with intermolecular structure. In mixtures containing > 0.2 mole fraction DMSO the solvated electrons have half-lives of 11–18 ns.The radiation produced oxidizing species in DMSO has a half-life of 1–4 µs and an absorption band centered at 600 nm. This species seems to be present in all DMSO/H2O mixtures.Pure DMSO gives a free-ion yield in the range 1.2 to 1.8, as determined separately for the oxidizing and reducing species by bromide and anthracene scavenging experiments respectively. This free-ion yield is in keeping with the dielectric constant of DMSO of 46. The yields in fully deuterated DMSO are ~30% higher than in the protonated material.

Primary mechanisms in the radiolysis of amines: pulse and γ-radiolysis of neutral and acidic ethylamine, n-propylamine and ethylenediamine

1979 ◽  
Vol 57 (15) ◽  
pp. 2013-2021 ◽  
Author(s):  
J. A. Delaire ◽  
J. R. Bazouin
Keyword(s):  
Allyl Alcohol ◽  
Molecular Hydrogen ◽  
Pulse Radiolysis ◽  
Solvated Electron ◽  
Infrared Band ◽  
Solvated Electrons ◽  
Upper Limits ◽  
Transient Spectra ◽  
Alkyl Ammonium

The transient spectra in pure ethylamine (EA), n-propylamine (nPA), and ethylenediamine (EDA) show, besides the visible and infrared band associated with the solvated electron, e−s, a small ultraviolet band attributed to oxidizing radicals. Upper limits for the recombination rate constants k of e−s with the acidic cation are 1.5 × 1012 L mol−1 and 3.5 × 1012 L mol−1s−1 in EA and nPA respectively, and k = 2 × 1010 L mol−1 s−1 in EDA. The yield of e−s at 3 ns (G(e−s)3ns = 1.5, 1.2, and 3.1 molecules/100 eV in EA, nPA, and EDA respectively) has been deduced by biphenyl scavenging. The yield of molecular hydrogen after γ-radiolysis G0(H2) = 5.7 and 3.6 in pure nPA and EDA respectively. The effect of solutes, such as biphenyl, alkyl-ammonium chloride, and allyl alcohol, on G(H2) is interpreted in terms of scavenging of e−s and/or H atoms. From the pulse-radiolysis determination of G(e−s), we deduce [Formula: see text] in nPA.Finally, the decay of solvated electrons seems to occur only via recombination with the cation in EA and nPA, but in EDA there is a competition between this reaction and reaction with oxidizing radicals.

Production of solvated electrons, ion-paris and alkali metal anions in tetrahydrofuran studied by pulse radiolysis

1974 ◽  
Vol 24 (3) ◽  
pp. 366-368 ◽  
Author(s):  
G.A. Salmon ◽  
W.A. Seddon
Keyword(s):  
Alkali Metal ◽  
Pulse Radiolysis ◽  
Solvated Electrons ◽  
Metal Anions
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