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

The effects of an hydroxy substituent on ¹³C¹³C coupling constants and ¹³C chemical shifts have been measured in 1‐hydroxynaphthalene‐2‐¹³C and 1‐hydroxypyrene‐1‐¹³C. The changes observed in the ¹³C¹³C 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 ¹³C¹³C coupling constants.