Chalcogen-bonding-mediated chiral recognition and enantioenrichment of organoselenocyanates

Abstract

Chalcogen bonding (ChB) is recognized as an essential intermolecular interaction in Group VIA element-containing materials. The multiple σ-holes with high directionality endow ChB with potential for chiral functions, including recognition, sensing and chiroptical materials. Herein, we employ ChB to enable chiral sensing and enantioenrichment and separation of organoselenocyanates. A library of organic selenocyanate derivatives was constructed, and their complexation with a chiral phenanthroline conjugated foldamer was driven by ChB, aided by hydrogen bonding and π-stacking forces. The deep chiral environment of the foldamer enables binding affinity bias towards enantiopure selenocyanates, yielding differential spectroscopic output and binding constants. ChB-mediated chiral recognition also impacts self-assembly, indicating that the emergence of macroscopic chirality is controlled by the enantiomeric matching effect. Finally, we realized efficient enantioenrichment of the organoselenocyanates utilizing ChB-assisted chiral recognition for the first time, which establishes a new route for the chiral separation of Se-containing pharmaceuticals by σ-hole interactions.