13C13C spin coupling constants in tetrahydronaphthylene, hexahydrobenzanthracene and benzo[a]pyrene derivatives

The 13C13C spin coupling constants have been determined in substituted [1-13C]tetrahydronaphthylenes, [5-13C]hexahydrobenzanthracenes and [5-13C]benzanthracene. In addition, the 13C13C spin coupling constants for 7-hydroxy[7-13C]benzopyrene, trans-7,8-dihydro[7-13C]benzopyrene-7,8-diol and trans-7,8-dihydro[10-13C]benzopyrene-7,8-diol are reported, together with the one-bond carbon-carbon coupling constants between C-4 and C-5 in selected 4,5-disubstituted benzopyrenes. Values for the directly bonded coupling constants and long-range coupling constants are similar to those reported previously for other aromatic and aliphatic systems. Substituent effects on carbon-carbon coupling are compared for similarly substituted cyclic and acyclic systems.