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

Abstract

The ⁴J(H-C^-C-Me) coupling constant, previously established^1-3 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.