Dipole moments,Kerr constants,and structure of oxides of substituted norbornenes

The molar Kerr constants and dipole moments at infinite dilution in CCl₄ have been measured for these compounds and also for dicyclopentadiene dioxide and the oxides of ethylene, propylene, and tetramethylethylene. The dipole moment indicates an exo-oxide structure for endo-cyanonorbornene, and this fact is used with the Kerr constants for endo-cyanonorbornene and ethylene oxide to calculate the axes of the polarizability ellipsoid for the oxide ring: b₁ (along the symmetry axis), b₂ (in plane of ring), and b₃ (perpendicular to plane of ring). The Kerr constants for propylene and tetramethylethylene oxides have been used to determine the anisotropy in the polarizability of the C-C bond adjoining the oxide ring. The results demonstrate an exo mode of oxidation of all substituted norbornenes and an exo-exo structure for dicyclopentadiene dioxide.