Authors: P. Jiang, Y. Katsumura, M. Domae, K. Ishikawa, R. Nagaishi, K. Ishigure In the pulse radiolysis of concentrated phosphoric acid solutions, the direct action of radiation on phosphoric acid gives rise to the phosphate radical. The yields of the phosphate radical and the hydroxyl radical are proportional, respectively, to the electron fractions of phosphoric acid and water, and can…
Authors: M. Nakashima, E. Hayon The flash photolysis of air-free aqueous acetone solutions was shown to produce CH2COCH3 and (CHg^COH radicals. The acetonyl CH2COCH3 radical has an absorption maximum at 295 nm and an extinction coef- ficient 6295 = 800 ± 150 M-1 cm-1. No intermediates could be observed in the flash photolysis of air-free aqueous amide solutions. In presence…
Authors: G. V. Buxton, R. M. Sellers Pulse radiolysis of aqueous solutions of formic acid and formate ion in the pH range 0-13 shows (i) that the absorption spectrum of the carboxyl radical is constant between pH 2.5 and 13, but decreases in intensity between pH 2.5 and 0 ; (ii)that the effect of ionic strength on the rate of…
Authors: W. Wang, M. N. Schuchmann, Vinzens Bachler, H. Schuchmann, C. Sonntag Hydroxymethyl radical•CH2OH and its radical anion •CH2O- (pKa 10.7) were generated pulse-radiolytically in N2O-saturated aqueous solutions of methanol. The overall decay is by second-order kinetics. At pH ≤ 8 (•CH2OH, 2k = 1.7 × 109 dm3 mol-1 s-1), one observes ethylene glycol and formaldehyde plus methanol in a…
Authors: P. S. Rao, M. Simic, E. Hayon The reaction rate constants of e-/sub aq/ and OH radicals with imidazole (ImH), N-methylimidazole (MeIm), histidine, and N-methylhistidine were determined. The k(e-/sub aq/ + S) values were strongly dependent on the state of protonation of the ”pyridine” nitrogen in these molecules, with rates of approximately 5 x 109 M-1 sec-1 at pH…
Authors: M. Simic, P. Neta, E. Hayon A detailed pulse radiolysis study of aqueous solutions of methanol, ethanol, isopropyl alcohol, n-, iso-, and t-butyl alcohols, neopentanol, and eyelohexanol has been carried out. Optical absorption spectra of some of the transients have been measured down to 210 nm. Similar spectra were obtained in liquid methanol, ethanol, and isopropyl alcohol. Absorption maxima…
Authors: Lj. Josimović , I. Draganić The radiation chemical yields of stable products were measured in deaerated and oxygenated solutions at low absorbed doses(~<10 krad), different pH values(1-3 and 7.8) and various acetic acid concentrations(0’1-17mol dm-a). For a dilute solution(0″1mol dm-a) the results obtained support a simple reactions cheme.At larger acetic acid concentrations yields of stable products change proportionally to…