Abstract: Photochemical nitrogen elimination from l-(diazomethyl)-8-methylnaphthalene (2) yields acenaphthene (3) via the reactive intermediates (8-methyl-I-naphthy1) carbene (a) and 1, 8-naphthoquinodimethane (b). The triplet biradical b was observed by absorption spectroscopy at 77 K and by laser flash photolysis at room temperature. The cyclization of triplet b to triplet 3 is forbidden by state symmetry. Two pathways for the reaction b-3 have ...
