Abstract: Irradiation (A> 300 nm or A= 480 f 6 nm) of 2-naphthyldiazomethane (4), matrix- isolated in argon at 10 K, gives a mixture of 2-naphthylcarbene (1) and 2, 3-benzobicycl0 [4.1. O] hepta-2, 4, 6-triene (2). 2-Naphthylcarbene (1) is characterized by infrared, UV/visible, and ESR spectroscopy and by chemical trapping with CO. 2, 3-Benzobicyclo [4.1. O] hepta-2, 4, 6-triene (2) is characterized by infrared and UV/visible spectroscopy. A ...