Photolysis of azacyclohexadienyl radical and pyridinyl radical in an acidic glassy matrix

Azacyclohexadienyl radicals (I) trapped in an acidic glassy matrix may be photolysed by u.v. light, giving rise to the allyl radical (III); it is shown that pyridinyl radicals (II) formed in an intermediate step are photoisomerised into radical (III).