Chiral Self-sorting of Giant Cubic [8+12] Salicylimine Cage Compounds

Chiral self-sorting is intricately connected to the complicated chiral processes observed in nature and no artificial systems of comparably complexity have been generated by chemists. However, only a few examples of purely organic molecules have been reported so far, where the self-sorting process could be controlled. Herein, we describe the chiral self-sorting of large cubic [8+12] salicylimine cage compounds based on a chiral TBTQ precursor. Out of 23 possible cage isomers only the enantiopure and a meso cage were observed to be formed, which have been unambiguously characterized by single crystal X-ray diffraction. Furthermore, by careful choice of solvent the formation of meso cage could be controlled. With internal diameters of d(in)=3.3-3.5 nm these cages are among the largest organic cage compounds characterized and show very high specific surface areas up to approx. 1500 m(2) g(-1) after desolvation.

Automated summary

Chiral self-sorting is intricately connected to natural chiral processes, with few purely organic molecules having controllable self-sorting processes observed. In this study, chiral self-sorting of large cubic [8+12] salicylimine cage compounds based on a chiral TBTQ precursor was successfully achieved, leading to the formation of enantiopure and meso cage isomers with controlled solvent choice. These cages are among the largest organic cage compounds characterized, exhibiting high specific surface areas up to approximately 1500 m(2) g(-1) after desolvation.