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For oxamide 70, formation of charge-separated species, Eq. (52), after photoexcitation was postulated as the activity mechanism (2). A similar mechanism was proposed for the 2-cyanoacrylate 71. Aryl benzoate 72 rearranges under UV radiation into a derivative of 2-hydroxybenzophenone (10,37), acting by the mechanism envisaged for 64 [see Eq. (49)].