Photochemical Generation of Paramagnetic Species

Having briefly summarized most of the common methods available for ESR studies, we now turn to some illustrations of those fruitful areas where photochemical technique has made a significant contribution. 

A recent review by Symons (176) dealt with ESR studies of radiation damage in inorganic solids. It is well known that trapped electrons or F centers may be produced by photolysis of inorganic compounds. Recently Froben and Willard (177) reported the photoionization of metal atoms, such as Li, K, Na, Mg, and Cd, and observed by ESR the electrons trapped in 3-methylpentane at 77°K. 

However, I atoms have been extensively studied by steady- 

Photolysis of rare gas matrices containing small amounts 

A number of diatomic and polyatomic inorganic radicals have been produced in photochemical systems. Some of these radicals are listed in Table 2. Recently Martin and Swift (189) observed, during the photolysis of ceric perchlorate acid glass, ESR spectra similar to those of methyl radicals and intuitively assigned them to H O radicals. Given that these spectra have been correctly analyzed, it is difficult to understand how their ESR parameters could relate to the 6 radical H O. Confirmation of the assignment must await further detailed study. 17 

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