Fluorescence enhancement via structural rigidification inside a self-assembled Pd4 molecular vessel

Restriction of intramolecular motion (RIM) is fundamental for the high emission of aggregation-induced emission (AIE)-active molecules in aggregates or the solid-state. However, they are weakly emissive in dilute solution, which limits their application in dilute solutions. A Pd-4 molecular vessel (MP1) was constructed by assembling [cis-(en)Pd(NO3)(2)] (M) with a tetradentate donor (L) in a 2:1 molar ratio. The active intramolecular motions of an AIE active molecule SG are restricted in the narrow cavity of MP1 upon encapsulation. As a result, SG displayed significant enhancement in its emission in dilute solution upon addition of MP1. This strategy of achieving high emission of AIE active compounds in dilute solution by confinement driven RIM might have potential in designing materials for high emission in the aggregated state as well as in dilute solution.

Automated summary

This study investigates the enhancement of emission of aggregation-induced emission (AIE)-active molecules in dilute solution by restricting intramolecular motion (RIM). A Pd-4 molecular vessel (MP1) was assembled to restrict the active intramolecular motions of AIE active molecule SG. SG showed significant enhancement in emission in dilute solution upon addition of MP1. This strategy has the potential to design materials for high emission in the aggregated state as well as in dilute solution.