The reaction of OH radicals with acetic acid 2‐hydroxyethyl ester, (1), in aqueous solutions has been studied. A rate constant of k(OH + 1) = 8.5 · 108 M−1 s−1 was obtained. The transients a few μs after pulse consist of ∼83% formylmethyl radicals, CH2CHO, the remainder being mainly CH3C(O)OCHCH2OH radicals, (3). γ‐radiolysis of 1 in N2O saturated aqueous solutions led to G(acetic acid)=5.0 without contribution of a chain reaction. It is concluded that the OH attack on 1 leads mainly to the redical CH3C(O)OCH2CHOH, (2), which undergoes a fast fragmentation into acetic acid and the formylmethyl radical: A lower limit of the rate constant of this reaction, at 20°C, κ 5·105s−, was derived from pulse radiolysis studies and an upper limit of κ ≤ 5·106s−1 was estimated from scavenging experiments with oxygen under Co60‐γ‐irradiation. At higher concentrations of 1, and/or higher temperatures CH2CHO attacks 1, leading to a chain decomposition of 1 yielding acetic acid and acetaldehyde. Succinic aldehyde was identified as a product of the dimerization of CH2CHO.

Films (570-840 Á) of cyclohexane and n-hexane at 77°K have been subjected to low-energy electron impact and the products have been analyzed. The yield of bicyclohexyl onsets at -8.5 eV, maximizes at -13 eV, and minimizes at -30 eV. Of the Ci2 products from n-hexane only n-dodecane was resolved in the gas chromatogram. The onset is well below the threshold of optical absorption. Only the n-hexane fragment hydrocarbon products ethane, propane, n-butane, n-pentane, and their congruent olefins (in the order of decreasing yields) were measured in detail. Their yield vs. energy profiles were similar with onsets at -3.5 eV, maxima at -6.5 eV, and minima at -7.0 eV. The results for n-hexane at low energy are attributed to decompositions from vibrationally excited, low-lying triplet states by direct excitation with spin exchange.

Radical Decay Mechanism, Acetic Acid Elimination, Pulse Radiolysis, Conductivity Changes, Acetic Acid 2-Hydroxyethyl EsterFrom conductivity changes following a 1 ^s electron pulse applied to N20 saturated H2O or D2O solutions of acetic acid 2-hydroxyethyl ester the rate constants of the monomolecular decay of the radical HO-CH-CH2-OCOCH3 (1) in H20 and of DO-CH-CH2-OCOCH3 in D2O were derived, reaction (1). HO-CH-CH2-OCOCH3 -> CH2CHO + CH3COO-+ H+ (1) 1A value of k\ of 5.5 • 10 5 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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