Classified Encapsulation of an Organic Dye and Metal-Organic Complex in Different Molecular Compartments for White-Light Emission and Selective Adsorption of C2H2 over CO2.

Encapsulating a certain guest molecule in an assigned molecular compartment and then endowing the corresponding potential remains a huge challenge for metal-organic frameworks. To this end, we demonstrate a good example, for the first time, based on an actinide-based MOF. The used MOF (namely, ECUT-300) shows a unique uranyl-TPE anionic skeleton with three distinct cages, viz., mesopore A (2.8 nm), mesopore B (2.0 nm), and micropore C (0.9 nm). Through solid-liquid reaction, a RhB+ molecule can be encapsulated into ECUT-300 with the exact location in mesopore B, whereas the encapsulation of a metal-organic cation of [Fe(tpy)2]3+ was observed with the location in micropore C, suggesting unprecedented classified encapsulation. Impressively, the potential of the resulting guest@MOF composites is also highly dependent on the type of encapsulated guest molecules, for example, white-light emission for RhB+ and selective adsorption of C2H2 over CO2 for [Fe(tpy)2]3+.