Kinetic and Thermodynamic Behaviors of Pseudorotaxane Formation with Macrocyclic BODIPY Trimers and the Remarkable Substituent Effect on Ring-Face Selectivity.

The thermodynamic and kinetic behaviors of the pseudorotaxane formation between the macrocyclic BODIPY trimers and unsymmetrical secondary ammonium guests are investigated. We find a remarkable substituent effect of the BODIPY trimer on the ring-face selectivity during the threading. The difference in the small substituents (H or CH) in the macrocyclic host molecules significantly modulated the thermodynamic and kinetic selectivity of the threading direction of the unsymmetrical ammonium ions.