Hyper-Crosslinked Porous Organic Nanomaterials: Structure-Oriented Design and Catalytic Applications

Hyper-crosslinked porous organic nanomaterials, especially the hyper-crosslinked polymers (HCPs), are a unique class of materials that combine the benefits of high surface area, porous structure, and good chemical and thermal stability all rolled into one. A wide range of synthetic methods offer an enormous variety of HCPs with different pore structures and morphologies, which has allowed HCPs to be developed for gas adsorption and separations, chemical adsorption and encapsulation, and heterogeneous catalysis. Here, we present a systematic review of recent approaches to pore size modulation and morphological tailoring of HCPs and their applications to catalysis. We mainly compare the effects of pore size modulation and morphological tailoring on catalytic applications, aiming to pave the way for researchers to develop HCPs with an optimal performance for modern applications.

Synthesis of Sulfonated Porous Organic Polymers with a Hydrophobic Core for Efficient Acidic Catalysis in Organic Transformations

Synthesis of sulfonated porous polymers with improved hydrophobicity and stability is of extreme importance in both academic research and industrial applications. However, there is often a trade-off between acidity and surface hydrophobicity of sulfonated polymers. In this study, we report a strategy for the synthesis of sulfonated porous organic polymers (S-PT) with improved hydrophobicity via free radical polymerization method by using a rigid and large multidentate monomer, 1,3,5-tri(4-vinylphenyl)-benzene, having a hydrophobic core. The results of vapor adsorption measurement show that S-PT has more hydrophobic properties than sulfonated poly(divinylbenzene) (S-PD), attributed to the hydrophobic core of its multidentate monomer. Furthermore, the optimization of sulfonation time established a balance between surface acidity and hydrophobicity. Under optimized conditions, S-PT afforded up to 113 mmol g^-1  h^-1 TOF in the esterification of oleic acid with methanol, more active than commercial Amberlyst-15 with TOF of 15 mmol g^-1  h^-1 and Nafion NR50 with TOF of 7 mmol g^-1  h^-1 . We believe that the findings of this study will provide useful insights to advance the design and synthesis of solid acid catalysts for organic transformations.

Fe3O4@Void@Microporous Organic Polymer-Based Multifunctional Drug Delivery Systems: Targeting, Imaging, and Magneto-Thermal Behaviors

Multifunctional drug delivery systems were designed and engineered by template synthesis of a microporous organic polymer (MOP) and by postsynthetic modification. Hollow MOP spheres bearing Fe₃O₄ yolks (Fe₃O₄@Void@MOP) were prepared by the synthesis of MOP on Fe₃O₄@SiO₂ nanoparticles and by successive silica etching. In addition to the magneto-thermal function of Fe₃O₄ yolks, an aggregation-induced emission (AIE) feature was incorporated into the Fe₃O₄@Void@MOP through a homocoupling of tetra(4-ethynylphenyl)ethylene to form Fe₃O₄@Void@MOP-TE. Folate groups were further introduced into Fe₃O₄@Void@MOP-TE through the postsynthetic modification based on the thiol-yne click reaction. The resultant Fe₃O₄@Void@MOP-TE-FA showed multifunctionality in antitumoral therapy via folate receptor targeting, doxorubicin delivery, AIE-based imaging, and the magneto-thermal feature.