A STUDY ON PRIMARY ION CAPTURE BY A SCAVENGER UPON PULSE-RADIOLYSIS OF KETONES

Micro- and nanosecond pulse radiolysis of acetone, methyl ethyl ketone , and cyclopentanone in the presence of 10(-4) -0.02 mol/l anthracene was studied. It was shown that radiolytic transformations involving an thracene result in anthracenide ions S-. The main precursors of S- are the molecular anions of ketones. These anions react with anthracene a t rate constants of 7.3 x 10(9), 1.1 x 10(10), and 4.5 x 10(9) l mol(- 1)s(-1) in acetone, methyl ethyl ketone, and cyclopentanone, respectiv ely. The apparent yields of S- ions formed via reactions in the bulk a nd in the tracks of irradiated ketones were measured. The yields due t o reactions in the bulk are 1.47, 1.54, and 1.24 ion/100 eV and those for track reactions are 3.43, 3.26, and 3.77 ion/100 eV, respectively. The total yield of ionization of the ketones was estimated as approxi mately 4.8 - 5.0 ion/100 eV. About 70 - 80% of the anionic species pro duced disappear in inhomogeneous intratrack reactions and 20 - 30% tak e part in homogeneous reactions in the bulk of solution.