Emergent Conformational Preferences of a Self-Assembling Small Molecule:  Structure and Dynamics in a Tetrameric Capsule

Herein we report the synthesis of a molecule that self-organizes through hydrogen bonds into discrete tetrameric capsular species, encapsulating large polycyclic guest molecules. The unique folded structure of the assembled state is determined by correlation spectroscopy in conjunction with molecular modeling. Pendant methoxyl groups are essential for the assembly process and convey their influence through both electronic pathways and surface interactions. Spin polarization transfer experiments show that the capsule undergoes rapid guest-exchange processes while being itself kinetically stable at elevated temperatures.