13C13C spin coupling constants in tetrahydronaphthylene, hexahydrobenzanthracene and benzo[a]pyrene derivatives

The 13C13C spin coupling constants have been determined in substituted [1‐13C]tetrahydronaphthylenes, [5‐13C]hexahydrobenzanthracenes and [5‐13C]benzanthracene. In addition, the 13C13C 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.