Symmetric, Asymmetric, Dissymmetric, and Nondissymmetric Molecules

Before continuing the discussion of molecular structures that exhibit enan-tiomerism, it will be useful to review some designations of molecular 

The word chirality is attributed to Lord Kelvin (reference 42). 

New Developments in Molecular Chirality Kluwer Academic Publishers  

inversion of all atoms through a center of symmetry (center of inversion, i) 

rotation about an improper axis (S , corresponding to rotation about an axis followed by reflection through a plane perpendicular to that axis) 

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