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When a-(p-dimethylaminophenyl)-N -(m-nitrophenyl) nitrone (II) is irradiated in benzene to complete disappearance of the nitrone spectrum, it will reform nitrone to the extent of 60% after 24 hr. in the dark at room temperature. A hydrolytic reaction leading to 4-dimethylaminobenzaldehyde accounts for the remainder.as chemical energy. Further details and discussion will appear in a forthcoming publication.

The en:>l-keto tauta'cerism in radical cations has been ronsiderErl to involve a synmetry-forbidden l,3-hydrogen shift. An alternative process. involves t\\O ronsecuti ve 1,2-hydrogen shifts. The tili f ' s of the intennediate ions fomed by a l,2-hydrCX]en shift in the radical cations of phenol and the enol form of acetic acid have been calculatErl to be 220 and 191 kcal/nol, respectively., These tilii sindicate barriers to the keto-enol ~utanerj sm via t\\O Consecutive 1,2-hydrCX]en shifts of 50 and 47 kcal/nol, respectively, in go6d agreercent with previouslydetenninErl experimental values of 55 and 51 ,2:10 kcal/nol, respectively. Estimations of transition state energies for the tautanerism via tv.o ronsecuti ve 1,2-hydrCX]en shifts in the closErl shell systems , vinyl alrohol~acetaldehyde, H 2 c£H 3 ~ H3~2' and Cl1 3 Cl1==CcHfCl1 3 Cl1 2 0=cH 2 , indicate that the ass1..lITption of a synmetry-forbidden 1, 3-hydrCX]en shift is not requirErl.