Triptycene Walled Glycoluril Trimer: Synthesis and Recognition Properties.

We report the synthesis of a new acyclic CB[n]-type host (1) that features a central glycoluril trimer capped by triptycene sidewalls. Host 1 has good solubility in water (≈ 3 mM) and does not undergo strong self-association (Ks = 480 M-1). We probed the geometry of the complexes by analyzing the complexation induced changes in the 1H NMR spectra and measured the complexation thermodynamics by isothermal titration calorimetry. The conformation of 1 and its packing in the solid state was revealed by single crystal x-ray diffraction measurements.