Copper-Based Metal–Organic Frameworks (MOFs) as an Emerging Catalytic Framework for Click Chemistry

In the extensive terrain of catalytic procedures for the synthesis of organic molecules, metal–organic frameworks (MOFs) as heterogenous catalysts have been investigated in a variety of chemical processes, including Friedel–Crafts reactions, condensation reactions, oxidations, and coupling reactions, and utilized owing to their specific properties such as high porosity, tuneability, extraordinary catalytic activity, and recyclability. The eminent copper-tailored MOF materials can be exceptionally dynamic and regioselective catalysts for click reactions (1,3-dipolar cycloaddition reaction). Considering the fact that Cu(I)-catalyzed alkyne–azide cycloaddition (CuAAC) reactions can be catalyzed by several other copper catalysts such as Cu (II)-β-cyclodextrin, Cu(OAc)2, Fe3O4@SiO2, picolinimidoamide–Cu(II) complex, and Cu(II) porphyrin graphene, the properties of sorption and reusability, as well as the high density of copper-MOFs, open an efficient and robust pathway for regimented catalysis of this reaction. This review provides a comprehensive description and analysis of the relevant literature on the utilization of Cu-MOFs as catalysts for CuAAC ‘click’ reactions published in the past decade

Schiff base functionalized Organopropylsilatranes: Synthesis and structural characterization

Synthesis of Schiff bases linked to organopropylsilatranes were performed by condensation reaction of post-functionalized silatranes such as aminopropylsilatrane (4), aminopropyl-3,7,10-trimethylsilatrane (5) and N-substituted aminopropylsilatrane (10) with two different aldehydes viz. pyrrole-2-carboxaldehyde and 2-hydroxy- 1-napthaldehyde. The resulting Schiff base substituted silatranes were well characterized by elemental analysis, spectroscopic studies [IR, (H-1, C-13) NMR, and MS]. The structures of two silatranes were confirmed by single crystal X-ray diffraction analysis

Recyclable magnetic nickel ferrite–carboxymethyl cellulose–sodium alginate bio-composite for efficient removal of nickel ion from water

In waste water treatment, magnetic bio-composites are frequently investigated as an adsorbent recently due to their great capacity for adsorption and affordability. In this current work, an attempt has been made to develop spinel nickel ferrite–carboxymethyl cellulose (NiFCMC) composite and modified its surface by alginate polymer to form NiFCMC–Alg composite. Several techniques were utilized to characterize these adsorbents including Fourier transform infrared spectroscopy, x-ray diffraction, field emission scanning electron microscopy, energy-dispersive spectra, thermogravimetric analysis, vibration sample magnetometry and pH of point zero charge. These adsorbents were explored to check their potentiality to remove Ni (II) ions in aqueous medium on various parameters such as contact time, initial metal ion concentration, pH, adsorbent dose and temperature. The optimum time for establishment of equilibrium was 180 minutes at pH 8 with adsorbent dose of 0.1 g. Results of kinetic studies revealed that the best fit for the metal ion adsorption data was the Lagergren pseudo-second-order mode indicating the chemisorption nature. Likewise, the Langmuir isotherm model also showed good agreement with adsorption equilibrium data with maximum adsorption capacities 47.84 ± 2.39 and 60.24 ± 3.01 mg/g for NiFCMC and NiFCMC–Alg respectively. The calculated adsorption thermodynamic parameters confirmed the spontaneous nature of adsorption process. The regeneration efficiency of both adsorbents was studied for five cycles and showed significant results. This study has shown that NiFCMC and NiFCMC–Alg can be a good substitute for removing Ni (II) ions in aqueous medium.</p