Activated and activationless localization and impurity trapping of the dry electron in methanol and propanol. Rate constants for solvated electrons

1978 ◽  
Vol 82 (13) ◽  
pp. 1460-1465 ◽  
Author(s):  
Dusan Razem ◽  
William H. Hamill
Keyword(s):  
Rate Constants ◽  
Solvated Electrons

Switchover of reactions of solvated electrons with nitrate ions and ammonium ions in propanol–water solvents

1993 ◽  
Vol 71 (9) ◽  
pp. 1297-1302 ◽  
Author(s):  
Tae Bum Kang ◽  
Gordon R. Freeman
Keyword(s):  
Rate Constants ◽  
Pure Water ◽  
Reaction Rates ◽  
Binary Solvents ◽  
Ammonium Ions ◽  
Concentrated Solutions ◽  
Solvated Electrons ◽  
Reaction Rate Constants ◽  
Water Solvent ◽  
Arrhenius Temperature

The reaction rate constants of [Formula: see text] with ammonium nitrate (~ 0.1 mol m−3) in 1-propanol-water and 2-propanol–water binary solvents correspond to [Formula: see text] reaction in the water-rich solvents, and to [Formula: see text] reaction in alcohol-rich solvents. The overall rate constant is smaller in solvents with 40–99 mol% water, with a minimum at 70 mol% water. The Arrhenius temperature coefficient is 26 kJ mol−1 in each pure propanol solvent, increases to 29 kJ mol−1 at 40 mol% water, then decreases to 17 kJ mol−1 in pure water solvent. The high reaction rates in the single component solvents, alcohol or water, are limited mainly by solvent processes related to shear viscosity (diffusion) and dielectric relaxation (dipole reorientation). Rate constants reported for concentrated solutions (50–1000 mol m−3) of ammonium and nitrate salts in methanol (Duplâtre and Jonah. J. Phys. Chem. 95, 897 (1991)) have been quantitatively reinterpreted in terms of the ion atmosphere model.

The reactivity of allyl and propargyl alcohols with solvated electrons: temperature and solvent effects

1979 ◽  
Vol 57 (8) ◽  
pp. 839-845 ◽  
Author(s):  
Alexei M. Afanassiev ◽  
Kiyoshi Okazaki ◽  
Gordon R. Freeman
Keyword(s):  
Activation Energy ◽  
Ethylene Glycol ◽  
Rate Constants ◽  
Allyl Alcohol ◽  
Trap Depth ◽  
Activation Energies ◽  
Butyl Alcohol ◽  
Solvated Electrons ◽  
Tert Butyl ◽  
Tert Butyl Alcohol

The rate constants k1 for the reaction of solvated electrons with allyl alcohol in a number of hydroxylic solvents differ by up to two orders of magnitude and decrease in the order tert-butyl alcohol > 2-propanol > 1-propanol ≈ ethanol > methanol ≈ ethylene glycol > water. In methanol and ethylene glycol the rate constants (7 × 107 M−1 s−1 at 298 K) and activation energies (16 kJ/mol) are equal, in spite of a 32-fold difference in solvent viscosity (0.54 and 17.3 cP, respectively) and 3-fold difference in its activation energy (11 and 32 kJ/mol, respectively). The reaction in tert-butyl alcohol is nearly diffusion controlled and has a high activation energy that is characteristic of transport in that liquid (E1 = 31 kJ/mol, Eη = 39 kJ/mol). The activation energies in the other alcohols are all 16 kJ/mol, and it is 14 kJ/mol in water. They do not correlate with transport properties. The solvent effect is connected primarily with the entropy of activation. The rate constants correlate with the solvated electron trap depth. When the electron affinity of the scavenger is small, a favorable configuration of solvent molecules about the electron/scavenger encounter pair is required for the electron jump to take place. The behavior of the rate parameters for propargyl alcohol is similar to that for allyl alcohol, but k1, A1, and E1 are larger for the former. The ratio k(propargyl)/k(allyl) at 298 K equals 10.5 in water and decreases through the series, reaching 1.3 in tert-butyl alcohol. Rate parameters for several other scavengers are also reported.

Rate constants of reactions of photogenerated solvated electrons with monomers

1971 ◽  
Vol 10 (1-2) ◽  
pp. 129-131 ◽  
Author(s):  
P. N. Moorthy ◽  
Vijay Kumar ◽  
K. N. Rao ◽  
J. Shankar
Keyword(s):  
Rate Constants ◽  
Solvated Electrons

Mobilities of solvated electrons in polar solvents from scavenging rate constants

1980 ◽  
Vol 84 (10) ◽  
pp. 1186-1189 ◽  
Author(s):  
J. A. Delaire ◽  
M. O. Delcourt ◽  
J. Belloni
Keyword(s):  
Rate Constants ◽  
Solvated Electrons ◽  
Polar Solvents

Effect of Pressure on the Rates of Reaction of Hydrogen Atoms in the Radiolysis of Liquid Ethanol

1973 ◽  
Vol 51 (12) ◽  
pp. 2033-2040 ◽  
Author(s):  
Kamal N. Jha ◽  
Gordon R. Freeman
Keyword(s):  
Charge Transfer ◽  
Hydrogen Atom ◽  
Aromatic Ring ◽  
Rate Constants ◽  
Hydrogen Yield ◽  
Hydrogen Atoms ◽  
Solvated Electrons ◽  
Effect Of Pressure

Competition between the reactions[Formula: see text]and[Formula: see text]was measured at 296 K at 1 bar and 5.4 kbar. Values of k5/k3 at 1 bar and (ΔV5≠ − ΔV3≠) averaged between 1 bar and 5.4 kbar for several solutes S are: cyclohexene, 56, + 2.7 cm3/mol; hexene-1, 71, + 2.6 cm3/mol; phenol, 25, −3.8 cm3/mol; benzene, 12, −6.5 cm3/mol. The volume of activation of hydrogen atom addition to the aromatic ring is about 8 cm3/mol more negative than that of addition to a mono-olefin. Rate constants of reaction of solvated electrons with these solutes at 295 K, measured by the pulse-radiolysisspectroscopy technique, are (M−1 s−1): cyclohexene, <1 × 104; hexene-1, 1 × 105; benzene, 4 × 106; phenol, 5 × 107. The phenol reaction with e−solv does not reduce the hydrogen yield by a proportionate amount, so phenol "catalyses" the decomposition of e−solv to form hydrogen, perhaps via C6H5OH−solv → C6H5O−solv + H. The scavenging of hydrogen precursors by hexene-1, benzene, and aniline in n-hexane, reported in ref. 6, had [Formula: see text], −6, and −4 cm3/mol, respectively, all three of which may be attributed to hydrogen atom reactions. The yields of hydrogen from solutions of neohexane in cyclopentane at 1 bar and 5.4 kbar indicate that charge transfer occurs from cyclopentane to neohexane, and that the probability of charge transfer is independent of pressure. The methane yields from these solutions indicate that the decomposition of the neohexane ion formed by charge transfer from cyclopentane, to form methane, is inhibited by pressure.

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