This work reports the synthesis of pyridyltriazol-functionalized UiO-66 (UiO stands for University of Oslo), namely UiO-66-Pyta, from UiO-66-NH 2 through three post-synthetic modification (PSM) steps. The good performance of the material derives from the observation that partial formylation (~21% of -NHCHO groups) of H 2 BDC-NH 2 by DMF, as persistent impurity, takes place during synthesis of the UiO-66-NH 2 . Thus, to enhance material performance, firstly, the as-synthesized UiO-66-NH 2 was deformylated to give pure UiO-66-NH 2 . Subsequently, the pure UiO-66-NH 2 was converted to UiO-66-N 3 with nearly complete conversion (~95 %). Finally, the azide-alkyne[3+2]-cycloaddition reaction of 2-ethynylpyridine with the UiO-66-N 3 gave the UiO-66-Pyta. The porous MOF was then applied for the solidphase extraction of palladium ions from aqueous medium. Affecting parameters on extraction efficiency of Pd(II) ions were also investigated and optimized. Interestingly, UiO-66-Pyta exhibited selective and superior adsorption capacity for Pd(II) with maximum sorption capacity of 294.1 mg g -1 at acidic pH (4.5). The limit of detection (LOD) was found to be 1.9 µg L -1 . The estimated intra-day and inter-day precisions are 3.6% and 1.7%, respectively. Moreover, the adsorbent was regenerated and reused for 5 cycles without any significant change in the capacity and repeatability. The adsorption mechanism was described based on various techniques such as FT-IR, PXRD, SEM/EDS, ICP-AES, and XPS analyses as well as density functional theory (DFT) calculations. Notably, as a case study, the obtained UiO-66-Pyta after palladium adsorption, UiO-66-Pyta-Pd, was used as an efficient catalyst for Suzuki-Miyaura cross-coupling reaction.

The review summarizes the state-of-the-art of C–H active transformations over crystalline and amorphous porous materials as new emerging heterogeneous (photo)catalysts.

Organic photochemistry is intensely developed in the 1980s, in which the nature of excited electronic states and the energy and electron transfer processes are thoroughly studied and finally well‐understood. This knowledge from molecular organic photochemistry can be transferred to the design of covalent organic frameworks (COFs) as active visible‐light photocatalysts. COFs constitute a new class of crystalline porous materials with substantial application potentials. Featured with outstanding structural tunability, large porosity, high surface area, excellent stability, and unique photoelectronic properties, COFs are studied as potential candidates in various research areas (e.g., photocatalysis). This review aims to provide the state‐of‐the‐art insights into the design of COF photocatalysts (pristine, functionalized, and hybrid COFs) for organic transformations. The catalytic reaction mechanism of COF‐based photocatalysts and the influence of dimensionality and crystallinity on heterogenous photocatalysis performance are also discussed, followed by perspectives and prospects on the main challenges and opportunities in future research of COFs and COF‐based photocatalysts.

A porous multifunctional zirconium‐based metal–organic framework (MOF) was achieved by combined covalent and dative post synthetic modification (PSM) of the UiO‐66‐NH2, and characterized by a variety of techniques, including FTIR spectroscopy, powder XRD, N2 temperature‐programmed adsorption/desorption, scanning electron microscopy, thermal gravimetric analysis, inductively coupled plasma atomic emission spectroscopy, and UV/Vis diffuse reflectance spectroscopy. The MOF (Zr–MOF–FePC, PC=2‐pyridinecarboxaldehyde) is an active, efficient, and reusable catalyst for the one‐pot tandem photooxidative Passerini three‐component reaction of alcohols. This is a new type of tandem photocatalyst and cooperative catalyst and was obtained in the course of developing MOFs as versatile heterogeneous catalysts for diverse tandem oxidative multicomponent reactions. This work illustrates the potential of MOFs as multifunctional heterogeneous catalysts for sustainable chemistry.

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