Chiral and steric effects in ethane : a next generation QTAIM interpretation

Abstract

We introduce a development of next generation quantum theory of atoms in molecules (NG-QTAIM) for an investigation of the chirality of ethane. A new isomer type Qσ is discovered in addition to Sσ and Rσ stereoisomers in the stress tensor trajectory Uσ-space. The Qσ isomer is defined to be a ‘null-isomer’ since the value of the chirality-helicity function ≈ 0. The presence of chiral contributions suggests that steric effects, rather than hyper-conjugation, explain the staggered geometry of ethane. The steric effects, within the NG-QTAIM interpretation, are reduced by a factor of two using an electric-field directed down a CH bond.