Relation of rehybridization moments and bond moment theory

Abstract

A modified bond moment theory previously described ⁵ has been generalized so that a consideration of all vibrational modes of any molecule is possible. It is shown that the inclusion of a term to take homopolar moments into account is essential. A new definition of “bond moment” is proposed.

The discrepancies previously found for bond moments calculated from band intensities for vibrations of different symmetry classes are shown to arise from the neglect of the contribution from rehybridization moments.

A self-consistent value of µ_b(C [graphic omitted] H)= 0.22 ± 0.02 D is obtained from a consideration of the bond-bending B_1u, B_2u, B_3u vibrations of ethylene.