Eclipsed chiral rotamer

It is interesting to note that the solvents which form complexes with rac-131 do not form complexes with optically active 131 and vice versa. For example, the powdered (+)-131 obtained by the evaporation of THF from the (+)-130-THF complex turns to guest-free crystals by recrystallization from solvents indicated in Table 8. The big difference of the role between the solvents shown in Tables 8 and 9 is interesting. X-ray crystal structural analysis of a 1 1 complex of (S)-(-)-131 and 1,2-dichloroethane showed that the latter is accommodated in the cavity of the inclusion complex as a form of nearly eclipsed chiral rotamer, but no any significant interaction between the host and guest molecules is present.59... 

Toda, F., Tanaka, K., and Kuroda, R. (1997) Isolation of a Nearly Eclipsed Chiral Rotamer of 1,2-Dichloroethane as an Inclusion Crystal with a Chiral Host Compound, Chem. Commun., 1227-1228. 

Chirality provides similar examples. For instance, consider the fact that ethane has various levels of O3 in its chiral D3 rotamers, except for the eclipsed and staggered... 

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