Deliberate synthesis of the preselected enantiomer of an enantiorigid molecule with pure rotational symmetry T

Abstract

A carceplex with T symmetry of the type A₄B₆ has been synthesized enantiospecifically by employing the trianion of benzene-1,3,5-tricarboxylic (trimesic) acid as A and the R-cis-Rh₂(C₆H₄PPh₂)₂²⁺ cation as B. The chiral (C₂) B units abolish the symmetry planes required for T_d symmetry, thus leaving only the eight C₃ and three C₂ rotations of the group T. Racemization is impossible under any chemically interesting conditions. This would appear to be only the third case where both preselection of the desired enantiomer and enantiostability based on covalent bonding are achieved.