Experimental and computational studies of naphtho[2,3-c]tropone: a highly polarized novel troponid system

Irradiation of 6.7-(2',3'-aphtho)bicyclo[3.2.0]hepta-3,6-dien-2-one (10) in a rigid glass at -196 degreesC leads to the formation of hitherto unknown naphtho[2,3-c]tropone (3). which exhibits a characteristic UV-vis absorptio n extending to 700 nm and undergoes rapid [pi 12+pi 14] dimerization upon t hawing the glass. NICS(1) values calculated for a series of benzo- and naph tho-fused tropones suggest that aromatic character of the tropone ring in 3 is significantly increased relative to the parent system. (C) 2001 Elsevie r Science Ltd. All rights reserved.