SELECTING ETHANOL AS A MODEL ORGANIC SOLVENT IN RADIATION CHEMISTRY—Ⅱ. γ AND PULSE RADIOLYSIS OF THE ACETOPHENONE-ETHANOL SYSTEM

摘要

Both γ and pulse radiolysis of acetophenone in ethanol solutions have been studied. The dependence of G values of hydrogen, 2,3-butanediol and acetaldehyde on acetophenone concentration was examined. Four new γ radiolytic products of acetophenone (P1, P2, P3 and P4) were detected. The material balance between e_s~- and the ensuing products was achieved. The ratio of rate constants k(e_s~- + C_6H_5COCH_3)/k(e_s~- + CH_3CHO) was simulated by computer to be 5. Upon pulse radiolysis of acetophenone in Ar-saturated ethanol solutions, a C_6H_5CO~-CH_3 radical anion was formed with absorption peaks at 315 and 440 nm, which were assigned to the electron transition of π-π~* and n-π~* respectively, and the ratio of ε_(315)/ε_(440) was calculated to be 7.2. The molar extinction coefficient of acetophenone radical anion at 440 nm was determined to be 3847 mol~(-1) dm~3/cm and the absolute rate constant for the decay of acetophenone radical anion about 8 x 10~(10) mol~(-1) dm~3/s was obtained.