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Tannic acid, as a humic‐like substance with phenolic hydroxyl and carbonyl functional groups, can modify surface of Fe3O4 NPs. Moreover, it can improve surface properties and capacity of Fe3O4 for adsorption and reduction of palladium ions through complexing with them, in aqueous solutions. Therefore, Fe3O4@TA NPs have potentials of reducing, stabilizing and immobilizing palladium nano particles to generate novel magnetic palladium nanocatalysts. Inductively coupled plasma (ICP), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS), energy‐dispersive X‐ray spectrum (EDS), vibrating sample magnetometer (VSM) and Fourier transform infrared (FTIR) methods unraveled the catalyst properties. Investigation of Fe3O4@TA/Pd NPs performance illustrated its recycle nature and high catalytic activity towards Suzuki‐Miyaura cross‐coupling reactions and reduction of 4‐nitrophenol (4‐NP), at room temperature.

In recent days, nanohybrid metal organic frameworks (MOF) have been considered as next generation catalysts due to their unique features like large surface to volume ratio, tailorable geometry, uniform pore sizes and homogeneous distribution of active sites. In this report, we address the biguanidine modified 3D Zr-centred MOF UiO-66-NH2 following a post synthetic modification approach. Utilizing the excellent chelating ability of biguanidine, Pd ions are immobilized over the host matrix MOF. The as-synthesized material was physicochemically characterized using a broad range of analytical techniques like FT-IR, electron microscopy, EDS, elemental mapping, XRD and ICP-OES. Subsequently the material has been catalytically employed in the classical Suzuki–Miyaura coupling towards the synthesis of diverse biphenyl derivatives at sustainable conditions. There are very few reports on the covalently modified MOFs towards the organic coupling reactions. The catalyst has been isolated by centrifugation and recycled in 9 consecutive runs with almost insignificant leaching and minute decrease in reactivity.

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A Pd supported on 3,4-dihydroxypyridine (Py)-functionalized Fe3O4 (Fe3O4/Py/Pd) hybrid material has been synthesized for the first time.

We have designed a functionalized metal–organic framework (MOF) of UiO topology as a support, with an extremely high surface area, adjustable pore sizes and stable crystalline coordination polymeric structure and implanted copper (Cu) nanoparticles thereon.

A simple and practical strategy for the synthesis of a novel nano‐Fe3O4‐supported organocatalyst system based on 3,4‐dihydroxypyridine (Fe3O4/Py) has been developed. The prepared catalyst was characterized using Fourier transform infrared spectroscopy, transmission and scanning electron microscopies, X‐ray diffraction, vibrating sample magnetometry and energy‐dispersive X‐ray analysis. Accordingly, the Fe3O4/Py nanoparticles show a superparamagnetic property with a saturation magnetization of 61 emu g−1, indicating potential application in magnetic separation technology. Our experimental results reveal that the pyridine‐functionalized Fe3O4 nanoparticles are an efficient base catalyst for the domino condensation of various aromatic aldehydes, Meldrum's acid and 5‐methylpyrazol‐3‐amine under very mild reaction condition and in the presence of ethanol solvent. Moreover, the synthesized catalyst was used for one‐pot, three‐component condensation of aromatic aldehydes with barbituric acid and malononitrile to produce 7‐amino‐2,4‐dioxo‐5‐phenyl‐2,3,4,5‐tetrahydro‐1H‐pyrano[2,3‐d]pyrimidine‐6‐carbonitriles. All reactions are completed in short times and all products are obtained in good to excellent yields. Also, notably, the catalyst was reused five times without significant degradation in catalytic activity and performance. Copyright © 2016 John Wiley & Sons, Ltd.