Synthesis and characterization of butylamine-functionalized Cr(III)–MOF–SO3H: Synergistic effect of the hydrophobic moiety on Cr(III)–MOF–SO3H in esterification reactions

Phthalic anhydride (PA): a valuable substrate in organic transformations

This review has been centralized on applications of phthalic anhydride (PA) as a valuable and significant heterocyclic substrate in two- and multicomponent organic reactions. The article has been subdivided into the following parts: (i) PA introduction by focusing on its characterization, synthesizing procedure, and multiple-aspect applications. In addition, the previous review articles based on PA have also been indicated; (ii) the applications of PA as a substrate have been subdivided into parts with a glance on the reaction components numbers; (iii) the applications of PA in esterification reactions; and (iv) some examples of PA in multistep synthesis. The review covers the corresponding literature up to the end of 2022. According to the abovementioned classifications, PA is a potent substrate to design a wide range of heterocyclic compounds that possess various kinds of properties and applications in chemistry, industry, and pharmaceuticals.

Synthesis of Highly Efficient and Recyclable Bimetallic Cox-Fe1-x-MOF for the Synthesis of Xanthan and Removal of Toxic Pb2+ and Cd2+ Ions

Mono-(Fe) and bimetallic Co_x-Fe_1-x-MOF with different Co and Fe contents was successfully synthesized by the solvothermal method. The structural properties of the prepared samples were characterized by X-ray diffraction, transmission electron microscopy (TEM), Brunauer-Emmett-Teller specific surface area, and Fourier transform infrared spectroscopy. The results revealed the successful formation of mono and mixed Co_x-Fe_1-x-MOF. Also, the results of TEM displayed that the particle structure of Co_x-Fe_1-x-MOF changed to octahedral after the addition of cobalt. The surface acidity results illustrated that the samples showed both Lewis and Brønsted acid sites, and Co_x-Fe_1-x-MOF possessed more surface acidity than Fe-MOF. The catalytic performance of the prepared samples was tested by synthesis of 14-phenyl-14H-dibenzo [a, j] xanthene (xanthene), and bimetallic Co_x-Fe_1-x-MOF showed higher activity compared to monometallic Fe-MOF. The sample with Co_0.50-Fe_0.50-MOF gave the highest yield of xanthene with 90.2%. In addition, the prepared samples were used for removal of Pb²⁺ and Cd²⁺ ions from the aqueous solution. The sample with Co_0.50-Fe_0.50-MOF showed the highest removal efficiency compared with mono- and other bimetallic samples. The results illustrated that the addition of Co to Fe enhanced the structural properties, acidity, and catalytic performance of the prepared samples due to the synergistic effect between Fe and Co ions. According to the obtained results, the prepared samples showed great potentials for the synthesis of pharmacologically active compounds and environmental protection.

High-Performance Heterogeneous Thermocatalysis Caused by Catalyst Wettability Regulation

Catalyst wettability regulation has emerged as an attractive approach for high catalytic performance for the past few years. By introducing appropriate wettability, the molecule diffusion of reactants and products can be enhanced, leading to high activity. Besides this, undesired molecules are isolated for high selectivity of target products and long-term stability of catalyst. Herein, we summarize wettability-induced high-performance heterogeneous thermocatalysis in recent years, including hydrophilicity, hydrophobicity, hybrid hydrophilicity-hydrophobicity, amphiphilicity, and superaerophilicity. Relevant reactions are further classified and described according to the reason for the performance improvement. It should be pointed out that studies of utilizing superaerophilicity to improve heterogeneous thermocatalytic performance have been included for the first time, so this is a comparatively comprehensive review in this field as yet.

Preparation of monosodium 2-sulfoterephthalate to make a MIL-101(Cr)–SO3H catalyst

MIL-101(Cr)-SO3H has excellent thermal and chemical stabilities, making it an ideal porous acid catalyst for many organic reactions and petrochemical industries. It's starting ligand can be lab-prepared.

Mass spectrometry for multi-dimensional characterization of natural and synthetic materials at the nanoscale

Characterization of materials at the nanoscale plays a crucial role in in-depth understanding the nature and processes of the substances. Mass spectrometry (MS) has characterization capabilities for nanomaterials (NMs) and nanostructures by offering reliable multi-dimensional information consisting of accurate mass, isotopic, and molecular structural information. In the last decade, MS has emerged as a powerful nano-characterization technique. This review comprehensively summarizes the capabilities of MS in various aspects of nano-characterization that greatly enrich the toolbox of nano research. Compared with other characterization techniques, MS has unique capabilities for real-time monitoring and tracking reaction intermediates and by-products. Moreover, MS has shown application potential in some novel aspects, such as MS imaging of the biodistribution and fate of NMs in animals and humans, stable isotopic tracing of NMs, and risk assessment of NMs, which deserve update and integration into the current knowledge framework of nano-characterization.

The applications and prospects of hydrophobic metal-organic frameworks in catalysis

In recent years, large numbers of hydrophobic/superhydrophobic metal-organic frameworks (MOFs) have been developed. These hydrophobic MOFs not only retain rich structural variety, highly crystalline frameworks, and uniform micropores, but they also have lower affinity towards water and boosted hydrolytic stability. Until now, there were two main strategies to prepare hydrophobic MOFs, including a one-step method and post-synthesis modification (PSM). PSM was an often-used strategy for preparing hydrophobic MOFs. Hydrophobic MOFs showed unique advantages when used as catalysts for various categories of reactions. Herein, recent research advances relating to hydrophobic MOFs in the catalytic field are presented. The catalytic activities of hydrophobic MOFs and corresponding hydrophilic ones are also compared, and the superiority of hydrophobic MOFs or MOF materials as catalysts in 10 reactions is discussed. Finally, the advantages of hydrophobic MOFs as catalysts or auxiliary materials are summarized and promising future developments of hydrophobic MOFs are highlighted.