N.M.R. Studies of Bond Order in Sterically Distorted Phenanthrenes

Abstract

The 4J(H-C-C-Me) coupling constant, previously established1-3 as a probe of bond order, was used to examine the bond orders in 2,4,5,7-tetramethylphenanthrene. There was no evidence indicating disturbance of π-electron distribution in the C1/C2 and C2/C3 bonds, despite large deviations from planarity in the carbon skeleton of the molecule.