(3)
The sign (±) of the chirality Cσ, bond twist
Tσ and bond-axiality Aσ determines the
dominance of Sσ (Cσ> 0) and Rσ (Cσ< 0) character. A high degree of bond-axiality
Aσ corresponds to a large difference in the value of the{e3σ.dr}max for the
CCW and CW torsion directions.
The stereoisomeric excess Xσ is defined as the ratio of
the magnitude of the Cσ values of the Saand Ra stereoisomers of the torsional C1-N7 BCPand represents the Next generation QTAIM interpretation of the
enantiomeric excess.