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

Self Cite

. Can. J. Chem. 62, 1265Chem. 62, (1984.Reaction of solvated electrons with nitrobenzene, N, is nearly diffusion controlled in both pure solvents; kN -10"'dm3/mol s. The value of kN is approximately proportional to the inverse viscosity -r-' in the pure solvents, and in the mixed solvents at different temperatures. However, on going from zero to 74 mol% water at the same temperature kN is independent of the 40% increase of -q. Electron diffusion in the mixed solvents is not a simple function of fluidity.Reaction with the inefficient scavengers tryptophane (ks -10" dm3/mol s) and phenol (ks -lo7-10' dm3/mol s) correlates inversely with the electron optical absorption energy. The latter is related to the trap depth in the solvent; electrons in deeper traps have less tendency to react with molecules of low electron affinity.Addition of 3 mol% 2-PrOH to water at 296 K increases the value of GE,,,.,, by 16%. although the value in pure 2-PrOH is three-fold smaller than that in pure water. The increase is attributed to an increase in the free ion yield, caused by an increase in the product of the electron thermalization range and the microscopic dielectric constant of the fluid between the ion and electron, averaged over the time that they exist as a correlated pair. Addition of a small amount of alcohol to water increases the orderliness of the water structure.JOANNA CYCLER et GORDON R. FREEMAN. Can. J . Chem. 62, 1265 (1984). La reaction des Clectrons solvatCs avec le nitrobenzkne, N, est une rCaction qui est a toutes fins pratiques contr61Ce par la diffusion dans les deux solvants a I'Ctat pur; kN -10"' dm2/mol s. La valeur de kN est approximativement proportionnelle I'inverse de la viscositC -r-' dans les solvants purs et dans les solvants mixtes a diffkrentes tempkratures. Cependant, si on opkre a une temptrature constante et que I'on fait varier la quantitC d'eau de zCro jusqu'i 74 mol% d'eau, la valeur de kN ne varie pas malgrC une augmentation de 40% de la valeur de T. La diffusion des Clectrons dans les solvants mixtes n'est pas une fonction simple de la fluiditC.

Section: A Yields O F Solvated Electrorzssupporting

confidence: 93%

Section: A Yields O F Solvated Electrorzssupporting

confidence: 87%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of solvent structure on electron reactivity and radiolysis yields: 2-propanol/water mixed solvents

Cygler¹,

Freeman²

1984

Self Cite

“…Methanol and water are at opposite ends of the curve, which indicates that the reaction e; + NO;, in methanol has a different mechanism from that in water. The latter is a nearly diffusion-controlled reaction and the former is entropy-controlled (30). Throughout the series the variations of p, and E2 -EAo are similar.…”

Section: Trap-depth Model and Modificationmentioning

confidence: 76%

Solvent effects on the reactivity of solvated electrons with in C₁ to C₄ alcohols

Zhao¹,

Freeman²

1995

Self Cite

The rate constants [Formula: see text] in pure C1 to C4 alcohol solvents at 298 K increase with increasing viscosity and decreasing permittivity. Thus the reactivity increases with decreasing diffusivity and increasing coulombic repulsion, so the Debye–Smoluchowski model does not apply. The effective reaction radius κRr increases with decrease of effective trap depth Er/τ of the electrons in the solvent: κRr = CτRr(Er/τ)pτ. Values of κRr and Er/τ change with temperature, and values of Pτ fall in four categories: ∼0.0 for water and methanol; ∼1.3 for primary alcohols; 0.6 for secondary alcohols; 1.8 for tert-butanol. The C—H groups participate in the [Formula: see text] reaction. Keywords: alcohol solvents, solvated electron, nitrate ion, reactivity, solvent effects.

“…It is interesting to compare the rate constant for reaction of the hydrated electron with 1-hexyn-3-01, C H q -C H O H -(CH2),-CH, (8.6 x lo8 dm3 mol-I s-') to that of the electron reactlon with acetylene, CH-H (2.0 x lo7 dm3 mol-' s-') (6), and with propargyl alcohol, C H q -C H 2 0 H , of 2.1 x lo8 dm3 mol-' s-' (10). Substitution of the acetylene group greatly affects the rate of reaction towards the hydrated electron.…”

Section: Radiolysis Studies Of 1-hexyn-3-01mentioning

confidence: 99%

Radiolysis studies on the corrosion inhibitors 1 -hexyn-3-ol, cinnamonitrile, and 1,3-diethyl-2-thiourea

Elliot¹,

Chenier²,

Ouellette³

1995

Abstract:In this publication we report: (i) the rate constants for reaction of the hydrated electron with l-hexyn-3-01 ((8.6 ? 0.3) x lo8 dm3 mol-' s-' at lS°C), cinnamonitrile ((2.3 ? 0.2) x dm3 mol-I s-' at 2OoC), and 1,3-diethyl-2-thiourea ((3.5 ? 0.3) x lo8 dm3 mol-I s-I at 22'C). For cinnamonitrile and diethylthiourea, the temperature dependence up to 200°C and 150°C, respectively, is also reported; (ii) the rate constants for the reaction of the hydroxyl radical with 1-hexyn-3-ol((5.5 ? 0.5) x lo9 dm3 mol-I s-I at 20°C), cinnamonitrile ((9.2 ? 0.3) x lo9 dm3 mol-I s-I at 21°C), and diethylthiourea ((8.0 ? 0.8) x lo8 dm3 mol-I s-I at 22OC). For cinnamonitrile, the temperature dependence up to 200°C is also reported; (iii) the rate constant for the hydrogen atom reacting with 1-hexyn-3-01 ((4.3 ? 0.4) x lo9 dm3 mol-I s-' at 20°C).