Hydrogen-2 nuclear magnetic resonance spectra of cyclopentane and mesitylene trapped within channel-type inclusion compounds

²H NMR spectra of perdeuterated cyclopentane and mesitylene acting as guests in thiourea and cyclophosphazene inclusion compounds, respectively, were recorded between 140 and 297 K. The (basically) temperature-invariant line shapes imply rapid puckering of the cyclopentane ring and suggest a permanent tilt of roughly 42.5° or 70° with respect to the channel axis. The mesitylene rings orient in an upright position within the channels and rotate rapidly and uniformly about their C₂ symmetry axis. These results correlate with recent work on inclusion compounds, organic molecules absorbed by zeolites, and dopants dissolved in liquid crystalline solvents.