Substituent effects on 13C13C coupling constants and chemical shifts in 13C labelled polycyclic aromatic hydroxy compounds

Abstract The effects of an hydroxy substituent on 13 C 13 C coupling constants and 13 C chemical shifts have been measured in 1‐hydroxynaphthalene‐2‐ 13 C and 1‐hydroxypyrene‐1‐ 13 C. The changes observed in the 13 C 13 C couplings show the effect of a substituent attached directly to the labelled carbon or to a carbon ortho to this. In both situations the effect is a decrease in the numerical magnitude of most of the long range 13 C 13 C coupling constants.