Interpretation of the inductive effect of heteroatoms in substituted alkanes on the basis of both the one-electron density matrix and localized molecular orbitals

The general relation established previously between the one-electron density matrix (DM) of saturated organic molecules in the basis of bond orbitals and the relevant representation matrix of localized MOs (LMOs) was applied to investigate the inductive effect of heteroatoms in mono- and di-substituted alkanes. Local alterations in the electron density distribution after substitution peculiar to these systems were found to be accompanied by local changes in the extent of delocalization of the LMOs. This allowed the inductive effect to be interpreted in terms of either a perturbed DM or a change in shape of the LMOs compared to the corresponding situations in alkanes. Thus the well-known intuition-based account of the short-range nature of the inductive effect in alkanes being due to weak interbond delocalization was substantiated. The additive nature of the heteroatom influence is related to the additive nature of the interbond delocalization in alkanes.