Strategies to Obtain Enantiopure Conductors

Since these conductive materials are built from elementary bricks in the form of donors and acceptors, it is possible to introduce chirality by modifying either one or the other. In 

The substituents may be simple, for example methyl groups, or contain functionality, such as alcohols,terpenoid substituents,esters,hydroxyamides or oxazo-lidines. In these last cases, the substituents can be expected to be involved in the supramolecular architecture of the conductor, due to the polar nature of the functions involved and hence their potential interactions (tt-tt type or hydrogen bonds). The first enantiopure organosulfur donor, reported by Dunitz, was (,S,5,5,5)-TMET (S, S, S, S)- 

According to the authors, this difference in the crystal disorder accounts for the observed difference in conductivity between the racemic and enantiopure materials. 

Some examples of enantiopure modified ET organosulphur donors. 

Temperature dependence of the resistivity for (R)-(TTF-oxa)2AsF6 (R)-(6.13), (S)-(TTF-oxa)2AsF6 (S)-(6.13) and (rac)-(TTF-oxa)2AsF6 (rac)-(6.13) (reproduced with permission from reference copyright 2005, American Chemical Society). 

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