“Too Small, Too Big, and Just Right” − Optical Sensing of Molecular Conformations in Self-Assembled Capsules

Irradiation of dimethylbenzil within a cylindrical capsule gives bright green phosphorescence, while irradiation of benzil and dimethoxybenzil in the same capsule results in high energy blue fluorescence. This difference is likely due to the geometric restrictions imposed by the capsule's space on its excited guests, forcing a trans-planar conformation in some cases and cis-skewed in others.