The rates of the hydrogen abstraction rections of fluorine atoms with five halomethanes and two alkanes in the gas phase were studied using competitive methods. The main competitors were arranged in the following series in which adjacent pairs were fluorinated competitively :

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.

The reactions of the molecular ion have been studied as a function of the ion kinetic energy for methyl fluoride and methyl chloride. The following reactions are observed

The reactions of ·H, ·OH and e-aq with four viologens in aqueous solution were studied by spectrophotometry. With 1,1'-dimethyl-4,4'-bipyridinium dichloride, the main transient species caused by H reaction is the viologen radical cation formed by an electron-transfer reaction. Smaller amounts of a hydrogen-deficient radical are also formed by an abstraction reaction at one of the methyl groups together with a radical formed by addition of ·H to one of the rings. There is no evidence that a protonated radical cation species was formed. A similar pattern of reactivity is seen with 1,1',2,2'-tetra-methyl-4,4'-bipyridinium diperchlorate. However, the electron-transfer reaction is either absent in the case of 1,1',3,3'-tetramethyl-4,4'-bipyridinium diperchlorate or less important in 1,1',2,2',6,6'- hexamethyl-4,4'-bipyridinium dichloride, and the main initial transient is assigned to a hydrogen-deficient radical formed by an abstraction reaction at one of the ring methyl groups. The possible role of the hydrogen-deficient radical in reducing the loss of viologen observed in the photochemical splitting of water is discussed.

The ion-molecule reactions of eight highly halogenated derivatives of methane were studied in the gas phase using a mass spectrometer operated at high pressures. The compounds studied were CHCl3, CHCl2F, CHClF2, CHF3, CCl4, CCl2F2, CClF3, and CF4. These ionic systems were found to be less reactive than those of methane or the methyl and methylene halides. The main reactions observed were described as being halide ion transfer processes. The energy dependence of the cross sections and the rate coefficients of the reactant ions were determined.� Many rate coefficients for reactions between ions and polar molecules were found to be independent of the ion energy. Brief studies of the negative spectra at high pressures were also made.