Pulse radiolysis of aqueous solutions of N-Vinylpyrrolidin-2-one and Poly(N-vinylpyrrolidin-2-one)

1981 ◽  
Vol 34 (7) ◽  
pp. 1423 ◽  
Author(s):  
JE Davis ◽  
DF Sangster ◽  
E Senogles
Keyword(s):  
Aqueous Solutions ◽  
Hydroxyl Radical ◽  
Absorption Spectra ◽  
Rate Constant ◽  
Rate Constants ◽  
Pulse Radiolysis ◽  
Kinetic Method ◽  
Transient Species ◽  
Radical Scavengers ◽  
Dilute Aqueous Solutions

The absorption spectra of transient species produced when dilute aqueous solutions of N-vinylpyrrolidin-2-one (vp) and poly(N- vinylpyrrolidin-2-one) (pvp) are subjected to pulse radiolysis in the presence and absence of radical scavengers have been obtained and compared with those obtained from analogous compounds. The precise structure of the transients has not been established. Rate constants for the reaction of the hydroxyl radical with vp and pvp have been evaluated both by a competition kinetic method and by direct observation of the build-up of transient species: k(vp+·OH) = (6.4-8.1) × 109 dm3 mol-1 s-1 and k(pvp+·OH) = (1.5-2.3) × 108 dm3 mol-1 s-1 at 25°C. The rate constant for the reaction of the hydrated electron with vp has been determined as(1.6�0.3) × 109 dm3 mol-1 s-1 at 25°C. Rate constants for decay of the transient species have also been evaluated at 25°C: 2k(vp- OH·) = (8.1�1.0)× 108 dm3 mol-1 s-1; 2k(vp-e-) = (1.7�0.2) × 109 dm3 mol-1 s-1 and 2k(pvp-OH·) = (1.5�0.2) × 108 dm3 mol-1 s-1.

The pulse radiolysis of aqueous solutions of some inorganic compounds

1965 ◽  
Vol 286 (1406) ◽  
pp. 320-336 ◽  
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Absorption Spectra ◽  
Rate Constants ◽  
Pulse Radiolysis ◽  
Inorganic Compounds ◽  
Absolute Rate ◽  
Transient Species ◽  
Temperature Coefficients ◽  
Complex Metal

The reactions of the hydrated electron, e — aq. with a variety of inorganic metal ions, complex metal ions and anions have been investigated with pulses of 4 MeV electrons. Absolute rate constants have been measured in each case and some temperature coefficients have also been determined. Absorption spectra of transient species produced by the pulse have been obtained. Some of these species are unstable valency states produced by reduction withe — aq. , e.g. Ni + , Cr v ; others are the result of oxidation by OH, e.g. Cu 3+ . We have obtained rate constants for the reactions OH+Cu 2+ and H+MnO - 4 . The significance of the rate constants and spectra is discussed.

Conductometric Pulse Radiolysis Study on the Reaction of the Solvated Electron with 5-Bromouracil in Aqueous Solutions at Different pH Values

1974 ◽  
Vol 29 (1-2) ◽  
pp. 86-88b ◽  
Author(s):  
Burkhard O. Wagner ◽  
Herbert Klever ◽  
Dietrich Schulte-Frohlinde
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Atom ◽  
Aqueous Solutions ◽  
Hydroxyl Radical ◽  
Rate Constant ◽  
Pulse Radiolysis ◽  
Solvated Electron ◽  
Ph Values

To study the reaction of the solvated electron with 5-bromouracil an aqueous solution has been examined by conductometric pulse radiolysis at pH values between 4.68 and 8.74. Alcohol was added to scavenge the hydrogen atom and the hydroxyl radical. G(Br—) = (2.64 ± 0.08)/100 eV was found to be independent of the pH. The mobility of the bromouracil mono-anion was measured to be (2.7 ± 0.2) 10-4 cm2 V-1 s-1 at 20°C, and the rate constant of reaction (3b) was determined to be k(H+ BrUr-) = (2.3 ± 0.2) 1010 I mole-1 s-1*.

Notizen: Pulse Radiolysis of Selenium Containing Compounds: Selenomethionine

1974 ◽  
Vol 29 (7-8) ◽  
pp. 571-572 ◽  
Author(s):  
Maurizio Tamba ◽  
Sergio Bonora ◽  
Roberto Badiello
Keyword(s):  
Optical Absorption ◽  
Aqueous Solutions ◽  
Absorption Spectra ◽  
Pulse Radiolysis ◽  
Oh Radicals ◽  
Optical Absorption Spectra ◽  
Transient Species ◽  
Decay Kinetics ◽  
Kinetics Of

The pulse radiolysis of aqueous solutions of selenomethionine has been studied under both neutral and acid conditions and the transient optical absorption spectra have been observed. The reactivities of both eāq and OH radicals have been measured as well as the formation and the decay kinetics of the transient species.

A Pulse Radiolysis Study of the Reaction of the Sulfate Radical Ion in Aqueous Solutions of Styrene

1979 ◽  
Vol 32 (12) ◽  
pp. 2611 ◽  
Author(s):  
NA McAskill ◽  
DF Sangster
Keyword(s):  
Aqueous Solutions ◽  
Absorption Spectra ◽  
Pulse Radiolysis ◽  
Cation Radical ◽  
Ultraviolet Absorption ◽  
Sulfate Radical ◽  
Transient Species ◽  
Acetonitrile Solutions ◽  
Type Radical

The ultraviolet absorption spectra of the transient species formed during the pulse radiolysis of styrene and peroxydisulfate (S2O82)solutions showed that a benzyl-type radical was formed from styrene and the SO4- radical. The effect of adding Cl- was also studied. These results are in conflict with the claim1 that a phenylethyl radical was formed from SO4-' via the styrene cation radical. That study was made on acetonitrile solutions of styrene, S2O82-, CuCl2 and LiCl and the present results suggest that up to 70% of the SO4-' radicals may have been converted into Cl2-1 radical which then reacted with styrene.

A pulse radiolysis study of the reaction of OH with I2 and the decay of I2−

1992 ◽  
Vol 70 (6) ◽  
pp. 1658-1661 ◽  
Author(s):  
A. John Elliot
Keyword(s):  
Ionic Strength ◽  
Hydroxyl Radical ◽  
Time Dependence ◽  
Rate Constant ◽  
Rate Constants ◽  
Pulse Radiolysis

The rate constant for the reaction of the hydroxyl radical with iodine was estimated to be (9.5 ± 1.0) × 109 dm3 mol−1 s−1 at 20 °C from fitting the time dependence of the decrease in the absorption of iodine at 460 nm. A number of rate constants associated with the decay of I2− that were required for this fitting process were also determined. They were the reaction of I2− with I2− (2k = (4.6 ± 1.6) × 109 dm3 mol−1 s−1) at an ionic strength of 1.2 × 10−2 mol dm−3; I2− with I (k = (4.6 ± 1.6) × 109 dm3 mol−1 s−1); and I with I (2k = (3.0 ± 1.0) × 1010 dm3 mol−1 s−1).

The radiolysis of aqueous solutions of oxybromine compounds; the spectra and reactions of BrO and BrO 2

1968 ◽  
Vol 304 (1479) ◽  
pp. 427-439 ◽  
Keyword(s):  
Aqueous Solution ◽  
Steady State ◽  
Aqueous Solutions ◽  
Absorption Spectra ◽  
Rate Constants ◽  
Pulse Radiolysis ◽  
Kinetic Spectroscopy

Pulse radiolysis supplemented by steady state radiolysis of aqueous solutions containing some of the following solutes: N 2 O, Br - , BrO - , BrO - 2 , BrO - 3 , CO 2- 3 , and OH - has been used to identify the absorption spectra of BrO ( λ max = 350 nm) and BrO 2 ( λ max = 475 nm) and to evaluate the following rate constants (units, M -1 s -1 ): e - aq. + BrO - → Br - + O - (2.3 ± 0.5 x 10 10 ); e - aq. + BrO - 2 → BrO + O 2- (1.8 ± 0.2 x 10 10 ); e - aq. + BrO - 3 → BrO 2 + O 2- (4.1 ± 0.2 x 10 9 ); OH + BrO - → OH - + BrO (4.5 x 10 9 ); O - + BrO - → BrO + O 2- (4.6 x 10 9 ); OH + BrO - 2 → OH - + BrO 2 (1.9 x 10 9 ); Br - 2 + BrO - → BrO + 2Br - (8.0 ± 0.7 x 10 7 ); Br - 2 + BrO - 2 → BrO + Br - + BrO - (8.0 ± 0.8 x 10 7 ); BrO + BrO - 2 → BrO - + BrO 2 (3.4 ± 0.7 x 10 8 ); 2BrO 2 ⇌ Br 2 O 4 ( k = 1.4 x 10 9 and K = 19 M -1 ); Br 2 O 4 + OH - → H + + BrO - 2 + BrO - 3 (7 x 10 8 ); 2BrO + H 2 O → BrO - + BrO - 2 + 2H + (4.9 ± 1.0 x10 9 ); CO - 3 + BrO - → CO 2- 3 + BrO (4.3 ± 0.4 x 10 7 ); CO - 3 + BrO - 2 → CO 2- 3 + BrO 2 (1.1 ± 0.1 x 10 8 ). In contrast to their chlorine analogues, little is known of the chemistry of the bromine oxides in aqueous solution. In this paper we describe the methods of formation and identification of the radicals BrO and BrO 2 , and their reactions with various oxybromine species, as elucidated by the techniques of pulse radiolysis and kinetic spectroscopy applied to aqueous solutions containing oxybromine anions.

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

1995 ◽  
Vol 73 (12) ◽  
pp. 2137-2142 ◽  
Author(s):  
A.J. Elliot ◽  
M.P. Chenier ◽  
D.C. Ouellette
Keyword(s):  
Hydrogen Atom ◽  
Hydroxyl Radical ◽  
Temperature Dependence ◽  
Rate Constant ◽  
Rate Constants ◽  
Corrosion Inhibitors ◽  
Hydrated Electron

In this publication we report: (i) the rate constants for reaction of the hydrated electron with 1-hexyn-3-ol ((8.6 ± 0.3) × 108 dm3 mol−1 s−1 at 18 °C), cinnamonitrile ((2.3 ± 0.2) × 1010 dm3 mol−1 s−1 at 20 °C), and 1,3-diethyl-2-thiourea ((3.5 ± 0.3) × 108 dm3 mol−1 s−1 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) × 109 dm3 mol−1 s−1 at 20 °C), cinnamonitrile ((9.2 ± 0.3) × 109 dm3 mol−1 s−1 at 21 °C), and diethylthiourea ((8.0 ± 0.8) × 108 dm3 mol−1 s−1 at 22 °C). 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-ol ((4.3 ± 0.4) × 109 dm3 mol−1 s−1 at 20 °C). Keywords: radiolysis, corrosion inhibitors, rate constants.

Hydroxyl radical rate constants: comparing UV/H2O2 and pulse radiolysis for environmental pollutants

2008 ◽  
Vol 57 (6) ◽  
pp. 391-401 ◽  
Author(s):  
Michael S. Elovitz ◽  
Hilla Shemer ◽  
Julie R. Peller ◽  
K. Vinodgopal ◽  
Mano Sivaganesan ◽  
...  
Keyword(s):  
Hydroxyl Radical ◽  
Rate Constants ◽  
Pulse Radiolysis ◽  
Environmental Pollutants

The Mechanism of Decay of the Radical HO—CH—CH2—OCOCH3 in Aqueous Solutions. A Conductometric Pulse Radiolysis Study

1976 ◽  
Vol 31 (7) ◽  
pp. 960-964 ◽  
Author(s):  
G. Koltzenburg ◽  
T. Matsushige ◽  
D. Schulte-Frohlinde
Keyword(s):  
Acetic Acid ◽  
Aqueous Solutions ◽  
Rate Constants ◽  
Pulse Radiolysis ◽  
Electron Pulse ◽  
Rate Determining Step ◽  
A Value

From conductivity changes following a 1 µs electron pulse applied to Ν2Ο saturated H2O or D2Ο solutions of acetic acid 2-hydroxyethyl esterthe rate constants of the monomolecular decay of the radical HO-ĊH-CH2-OCOCH3 (1) in H2O and of DO-ĊH-CH2-OCOCH3 in D2O were derived, reaction (1).A value of k1 of 5.5 · 105 s-1 ± 25%, at 22 to 24°C, independent of the above solvents and of pH (or pD) was obtained. It is concluded that the rate determining step of reaction (1) is the heterolytic fragmentation of the carbon acetate bond in 1 followed by formation of H+.

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