One‐Handed Helical Tubular Ladder Polymers for Chromatographic Enantioseparation

Defect‐free one‐handed contracted helical tubular ladder polymers with a π‐electron‐rich cylindrical helical cavity were synthesized by alkyne benzannulations of the random‐coil precursor polymers containing 6,6′‐linked‐1,1′‐spirobiindane‐7,7′‐diol‐based chiral monomer units. The resulting tightly‐twisted helical tubular ladder polymers showed remarkably high enantioseparation abilities toward a variety of chiral hydrophobic aromatics with point, axial, and planar chiralities. The random‐coil precursor polymer and analogous rigid‐rod extended helical ribbon‐like ladder polymer with no internal helical cavity exhibited no resolution abilities. The molecular dynamics simulations suggested that the π‐electron‐rich cylindrical helical cavity formed in the tightly‐twisted tubular helical ladder structures is of key importance for producing the highly‐enantioseparation ability, by which chiral aromatics can be enantioselectively encapsulated by specific π‐π and/or hydrophobic interactions. Defect‐free tightly‐twisted single‐handed helical tubular ladder polymers with a highly π‐electron‐rich cylindrical helical cavity were synthesized thorough the quantitative and chemoselective helical ladderization of the rationally‐designed precursor polymers. The resulting helical tubular ladder polymers showed remarkably high enantioseparation abilities toward a variety of chiral hydrophobic aromatics with point, axial, and planar chiralities.