On the effects of electron correlation and conformational changes on the distortion of the charge distribution in alkyl chains

Several properties were calculated within the AIM framework for diverse conformations of linear 1-alkanols on HF/6-31++G∗∗//6-31G∗ and B3LYP/6-31++G∗∗//B3LYP/6-31G∗∗ electron densities. The results revealed that δ-methylene groups are indistinguishable from those placed further away from the functional group for O–Cα–Cβ–Cγ gauche units, whereas they are specific when this unit is antiperiplanar. The internal rotation around the Cα–O bond only gives rise to noticeable modifications in the α and β-methylenes. The inclusion of electron correlation does not modify these trends, but the dependence displayed by the energy of nearly transferable fragments on the molecular size changes from destabilisation (HF) to stabilisation (B3LYP).