High Fluorescence Porous Organic Cage for Sensing Divalent Palladium Ion and Encapsulating Fine Palladium Nanoparticles

Abstract

Comprehensive Summary Porous organic cages (POCs) as an innovative type of porous molecular materials enable multifunctional applications. Herein, a fluorescence POC (denoted as 1) has been constructed by means of 5,5'‐((2,5‐dimethoxy‐1,4‐phenylene)bis(ethyne‐2,1‐diyl))diisophthalaldehyde condensing with cyclohexanediamine enantiomer with the aid of trifluoroacetic acid. 1 exhibits the permanent void and prominent fluorescence with relative quantum yield of 73% confirmed by gas sorption and emission experiments, respectively. Moreover, this organic cage is capable of sensing diavalent Pd2+ according to the fluorescence response to the addition of various metal ions. The dispersion of 1 in methanol containing palladium acetate was stirred at 25 oC and then 80 oC to reduce Pd2+ ions into nanoparticles (NPs), leading to the composite (Pd@1) composed of fine Pd NPs with the size of ca. 1.8 nm. The catalytic nature of Pd@1 over NaBH4 promoted the degeneration of nitrobenzene and congo red. This work introduces one new case of POCs with versatile properties and functions, including ion fluorescence recognition, fine Pd NPs stabilizer, and gas adsorption, enriching the family of POC‐based materials.

Recent advances in the applications of porous organic cages

“…86 Compared with zeolites and MOFs, the metal nanoparticles within the POC hosts could easily form with uniform ultrafine sizes whereas the whole catalyst system exhibits good redispersibility in solvents. The most commonly reported MNPs that are encapsulated within POCs are Au, [87][88][89] Pd, 78,[90][91][92][93][94][95] and Ru. 96 In 2015, Sun et al 97 were the first to report immobilizing Rh nanoparticles (NPs) into an organic molecular cage, CC3-R (Fig.…”

“…86 Compared with zeolites and MOFs, the metal nanoparticles within the POC hosts could easily form with uniform ultrafine sizes whereas the whole catalyst system exhibits good redispersibility in solvents. The most commonly reported MNPs that are encapsulated within POCs are Au, 87–89 Pd, 78,90–95 and Ru. 96…”

Streamlining the automated discovery of porous organic cages

“…4 These advantageous features have gained POCs traction in the literature for their competitive porosities and guest selectivities, along with attractive applications in catalysis, chemical sensing, in thin-lm membranes for gas and molecular separations, and as porous liquids. [5][6][7][8] Despite this growing interest in POCs, the targeted design and realisation of new species has been a key challenge in the eld, exacerbated by the: (i) complexity of the species types that can form (i.e., thermodynamic vs. kinetic products, polymeric vs. discrete molecules, different cage topologies, Fig. 1); (ii) differing structural and thermodynamic stability of the resulting species (for example, subsequent cage catenation can occur aer cage formation); (iii) packing and potential polymorphism of the individual species; and (iv) the sensitivity of the properties to all of the above.…”

“…4 These advantageous features have gained POCs traction in the literature for their competitive porosities and guest selectivities, along with attractive applications in catalysis, chemical sensing, in thin-film membranes for gas and molecular separations, and as porous liquids. 5–8 Despite this growing interest in POCs, the targeted design and realisation of new species has been a key challenge in the field, exacerbated by the: (i) complexity of the species types that can form ( i.e. , thermodynamic vs. kinetic products, polymeric vs. discrete molecules, different cage topologies, Fig.…”

Streamlining the Automated Discovery of Porous Organic Cages

“…4 These advantageous features have gained POCs traction in the literature for their competitive porosities and guest selectivities, along with attractive applications in catalysis, chemical sensing, in thin-film membranes for gas and molecular separations, and as porous liquids. [5][6][7][8] Despite this growing interest in POCs, the targeted design and realisation of new species has been a key challenge in the field, exacerbated by the: (i) complexity of the species types that can form (i.e., thermodynamic vs kinetic products, polymeric vs discrete molecules, different cage topologies, Figure 1); (ii) differing structural and thermodynamic stability of the resulting species (for example, subsequent cage catenation can occur after cage formation); (iii) packing and potential polymorphism of the individual species; and (iv) the sensitivity of the properties to all of the above.…”