Author:
Garnett JL,Rains A,Wong PK
Abstract
The effect of
preirradiation with γ-rays from cobalt-60 and ultraviolet light from a
low-pressure source on the exchange between benzene and heavy water in the
presence of self-activated platinum oxide has been studied. Both rates of
multiple and stepwise exchange processes are accelerated under these
conditions. Of 14 oxides examined, including the Group VIII transition metals,
platinum is the only one to catalyse exchange up to 130�. Preliminary
experiments indicate that radiation-induced oxygen desorption from the surface
of the oxide is responsible for the accelerative effect. Internal radiation
sources such as tritium oxide also increase initial exchange rates.
Cholesterol, naphthalene, dibenzyl, diphenyl, benzoic acid, and diphenyl ether
have been studied with tritium oxide. The results can be rationalized in terms
of π- complex mechanisms for exchange. A catalytic model for the mechanism
of the radiation-induced effect is proposed.