Chiral Organic Cages with a Triple-Stranded Helical Structure Derived from Helicene.

We report the use of helicene with an intrinsic helical molecular structure to prepare covalent organic cages via imine condensation. The organic cages revealed a [3+2]-type architecture containing a triple-stranded helical structure with three helicene units arranged in a propeller-like fashion with the framework integrally twisted. Such structural chirality was retained upon dissolution in organic solvents, as indicated by a strong diastereotopy effect in proton NMR and unique Cotton effects in circular dichroism spectra. Further study on chiral adsorption showed that the chiral organic cages possess considerable enantioselectivity toward a series of aromatic racemates.

Homochiral hexanuclear nickel(ii) metallocyclic structures with high activity for the photocatalytic degradation of organic dyes.

Enantiopure ligands, namely (R,R)- and (S,S)-2,2'-(1,4-phenylene) bis(4,5-dihydrothiazole-4-carboxylic acid) (H2LRR, and H2LSS) were synthesized, and homochiral metallocyclic rings {Ni6LRR6(H2O)12} (1RR) and {Ni6LSS6(H2O)12} (1SS) were obtained and their structures were determined. The complexes exhibit excellent activity for the photocatalytic degradation of organic dyes.