Overview on magnetically recyclable ferrite nanoparticles: synthesis and their applications in coupling and multicomponent reactions

SiO2@Benzothiazole-Cl@Fc as an Efficient Heterogeneous Catalyst for the Synthesis of 1,3,5-Trisubstituted Pyrazoles by A3 Coupling

This research introduces the preparation and analysis of a newly heterogeneous catalyst developed silica nanospheres supporting a ferrocene-containing ionic liquid (IL) (SiO2@Benzothiazole-Cl@Fc) for the A3 coupling reaction. The catalyst facilitates the efficient synthesis of 1,3,5-trisubstituted pyrazoles from aromatic hydrazides, aldehydes, and aromatic alkynes. Incorporating ferrocene enhances the catalytic activity. Comprehensive characterization techniques, including NMR, Fourier transform infrared, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and scanning electron microscopy, confirm the successful functionalization of silica nanospheres. The catalytic performance was evaluated under various reaction conditions, demonstrating high yields and selectivity for the desired pyrazole products. This work highlights the potential of ferrocene-based ILs in green chemistry applications, providing a sustainable approach to synthesizing valuable heterocyclic compounds.

High-performance Fe3O4@SiO2@M-D and Fe3O4@SiO2@M-D-Cu with amine branches and decorated with copper metal for one-pot synthesis of chromene and xanthene derivatives

In this project, we introduced new heterogeneous nanocatalysts featuring amine branches and decorated with inexpensive copper metal (Fe3O4@SiO2@M-D-Cu and Fe3O4@SiO2@M-D). These nanocatalysts were characterized using several analytical techniques, including SEM, FT-IR, EDX, XRD, TGA, and ICP-OES. We investigated their catalytic activity in traditional pot reactions, focusing on the three-component synthesis of xanthene and chromene compounds. The properties and future potential of these nanocatalysts include high yield, recyclability, ease of operation, and the use of environmentally friendly solvents. Additionally, the catalysts can be easily removed from the reaction solution using an external magnet and reused up to eight times without a decrease in catalytic activity.

Bentonite/Ti(IV) as a natural based nano-catalyst for synthesis of pyrimido[2,1-b]benzothiazole under grinding condition

A new natural-based catalyst named Bentonite/Ti(IV) was prepared and characterized by FT-IR, FESEM, TEM, TGA, EDS-MAP, XRD, BET, XRF, XPS and ICP- MS. An efficient and simple one-pot three-component synthesis of pyrimido[2,1-b]benzothiazole derivatives was carried out by the reaction of aldehyde, 2-aminobenzothiazole, and ethyl acetoacetate. In this research, Bentonite/Ti(IV) was used for the synthesis of PBT derivatives in 80 °C under solvent-free conditions by electrical mortar-heater. Solvent-free conditions, simplicity of operation, easy work-up and use of an eco-friendly catalyst are some of advantages of this protocol.

Amine functionalized magnetic resorcinol formaldehyde as a green and reusable nanocatalyst for the Knoevenagel condensation

Herein, a novel amine-functionalized magnetic resorcinol-formaldehyde with a core-shell structure (Fe3O4@RF/Pr-NH2) is prepared through the chemical immobilization of (3-aminopropyl)trimethoxysilane over Fe3O4@RF composite. Characterization through FT-IR, EDX, PXRD, and TGA confirmed successful surface modification while preserving the crystalline structure of Fe3O4. The VSM analysis demonstrated excellent superparamagnetic properties, and SEM and TEM images revealed spherical particles for the designed nanocatalyst. The Fe3O4@RF/Pr-NH2 nanocomposite was employed as a robust nanocatalyst to promote the Knoevenagel condensation of benzaldehydes with ethyl cyanoacetate and malononitrile, resulting in the formation of substituted olefins. Various aromatic aldehydes were used as substrates in the presence of 0.01 g of Fe3O4@RF/Pr-NH2, achieving high to excellent yields (87-97%) within short reaction times (10-50 min) in EtOH at 60 °C. The high performance of Fe3O4@RF/Pr-NH2 is attributed to the hydrophobic nature of RF shell, which facilitates the accumulation of organic precursors around the catalytic active sites and enhances product yields. The designed magnetic catalyst could retain its high efficiency for at least ten runs. The metal-free, low-cost, and environmentally friendly attributes of the Fe3O4@RF/Pr-NH2 catalyst make it a promising alternative to traditional metal-based catalysts.

Distinct pathway of multiferroic silver-decorated zinc ferrite nanocatalyst performance for Acinate insecticide oxidation

The current study investigating the preparation and application of a Multiferroic nano-scale silver zinc ferrite substance (Ag0.5Zn0.5Fe2O4 nanocatalyst) has been established. Multiferroic silver zinc ferrite substance is prepared by co-precipitation technique as hybridized composite. This synethsized nanoparticles was characterized via X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) as well as Scanning Electron Miscospopy (SEM). Such nanoparticles are used as a sustainable recyclable photo-Fenton's reagent precursor for treating insecticide in wastewater. The results revealed a high Acinate oxidation rate reached to 97% removal within 40 min of irradiance time. To increase the performance, the operating variables are optimized. pH 3.0 and 40 and 400 mg/L for Ag0.5Zn0.5Fe2O4 and hydrogen peroxide, respectively are identified as the optimum values. Also, kinetics and thermodynamic are evaluated and the reaction is subsequent the first-order kinetics model and exothermic and non-spontaneous in nature with a low energy barrier of 35.02 kJ/mol. The advantage of Ag0.5Zn0.5Fe2O4 catalyst is its sustainability since it recovered for multiple reuse with a high activity reached to 80% removal rate after six cyclic use compared to 97% of fresh catalyst use.

Based on magnetically recoverable catalysts: a green strategy to sulfonamides

The synthesis of sulfonamides, a class of compounds with significant pharmaceutical and medicinal applications, has seen remarkable advancements with the advent of magnetic nanocatalysts. Magnetic nanocomposites are one of the most efficient and widely used catalysts, and they are in complete harmony with the principles of modern green chemistry from the point of view of catalysis. These catalysts, typically composed of metal complexes supported on magnetic nanoparticles, offer unique advantages such as ease of recovery and reusability, which are crucial for sustainable and eco-friendly chemical processes. This review comprehensively examines recent developments in applying magnetic nanocatalysts to prepare sulfonamides. Key focus areas include the design and synthesis of various magnetic nanocatalysts (MNC), their catalytic performance in different reaction conditions, and mechanistic insights into their catalytic activity. By summarizing the latest research and technological advancements, this article aims to provide a valuable resource for researchers and practitioners in catalysis and pharmaceutical chemistry.

Ionic Liquids Immobilized Synthesis of New Xanthenes Derivatives and their Antiproliferative, Molecular Docking, and Morphological Studies

BACKGROUND

Xanthenes and benzoxanthenesare are highly valuable compounds in organic chemistry and medicinal chemistry. Xanthene derivatives were found to have many applications in medicinal chemistry.

OBJECTIVE

This work aims to explore the synthesis of xanthene derivatives with various substituents and find the possibility of their uses as anticancer agents.

METHODS

The basic starting compound through this work was the 2,3-dihydro-1H-xanthen-1-one (3), which was synthesized from the reaction of cyclohexan-1,3-dione and 2-hydroxybenzaldehyde. Compound 3 was used to synthesize new thiophene, pyrimidine, isoxazole, and thiazole derivatives based on the xanthenes nucleus. Fused xanthene derivatives were obtained through further heterocyclization reactions. Multicomponent reactions expressed in this work were carried out in the presence of solvent catalyzed by Et3N and in solvent-free ionic liquid immobilized catalyst.

RESULTS

Cytotoxicity for the newly synthesized compounds toward cancer cell lines was measured, and the results revealed that many compounds exhibited high inhibitions.

CONCLUSION

The antiproliferative activity of the synthesized compounds was studied on six selected cancer cell lines. The nature of the heterocyclic ring and the variations of substituted groups showed a high effect through the inhibitions of the tested compound.

Magnetite-supported montmorillonite (K10) (nanocat-Fe-Si-K10): an efficient green catalyst for multicomponent synthesis of amidoalkyl naphthol

Montmorillonite (K₁₀) loaded on magnetite silica-coated nanoparticles was made using simple co-precipitation methods. The prepared nanocat-Fe-Si-K₁₀ was analyzed using some techniques including field emission-scanning electron microscopy (FE-SEM), inductive coupling plasma-optical emission spectroscopy (ICP-OES), X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), Fourier transmission-infrared spectra (FT-IR), energy dispersive X-ray spectroscopy (EDS), and wavelength-dispersive spectroscopy (WDX). The catalytic activity of the synthesized nanocat-Fe-Si-K₁₀ has been examined in one-pot multicomponent transformations for the synthesis of 1-amidoalkyl 2-naphthol derivatives under solvent-free conditions. Nanocat-Fe-Si-K₁₀ was determined to be very active, having the ability to be reused 15 times without significant loss of catalytic activity. The suggested technique has several advantages, including excellent yield, minimum reaction time, a straightforward workup, and catalyst recycling, all of which are essential green synthetic aspects.

Heterogeneous Sono-Fenton like catalytic degradation of metronidazole by Fe3O4@HZSM-5 magnetite nanocomposite

In this research, Fe₃O₄@HZSM-5 magnetic nanocomposite was synthesized via a coprecipitation method for metronidazole (MNZ) degradation from aqueous solutions under ultrasonic irradiation which showed superb sonocatalytic activity. The synthesized magnetite nanocomposite was characterized by using field-emission scanning electron microscope-energy dispersive X-ray Spectroscopy, (FESEM-EDS), Line Scan, Dot Mapping, X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and Brunauer-Emmett-Teller (BET). To investigate the sonocatalytic activity of the Fe₃O₄@HZSM-5 magnetite nanocomposite, the sonocatalytic removal conditions were optimized by evaluating the influences of operating parameters like the dosage of catalyst, reaction time, pH, the concentration of H₂O₂, MNZ concentration, and pH on the MNZ removal. The MNZ maximum removal efficiency and TOC at reaction time 40 min, catalyst dose 0.4 g/L, H₂O₂ concentration 1 mM, MNZ initial concentration 25 mg/L, and pH 7 were achieved at 98% and 81%, respectively. Additionally, the MNZ removal efficiency in the real wastewater sample under optimal conditions was obtained at 83%. The achieved results showed that using Langmuir-Hinshelwood kinetic model K_L-H = 0.40 L mg^-1, K_C = 1.38 mg/L min) can describe the kinetic removal of the process. The radical scavenger tests indicated that the major reactive oxygen species were formed by hydroxyl radicals in the Sono-Fenton-like process. Evaluation of the nanocomposite reusability showed an 85% reduction in the MNZ removal efficiency after seven cycles. Based on the results, it can be concluded that Fe₃O₄@HZSM-5 were synthesized as magnetic heterogeneous nano-catalysts to effectively degrade MNZ, and the observed stability and recyclability demonstrated that Fe₃O₄@HZSM-5 was promising for the treatment of wastewater contaminated with antibiotics.

Investigation of Fe3O4@boehmite NPs as efficient and magnetically recoverable nanocatalyst in the homoselective synthesis of tetrazoles

Magnetic boehmite nanoparticles (Fe3O4@boehmite NPs) were synthesized from a hybrid of boehmite and Fe3O4 nanoparticles. At first, boehmite nanoparticles (aluminum oxide hydroxide) were prepared via a simple procedure in water using commercially available materials such as sodium hydroxide and aluminum nitrate. Then, these nanoparticles were magnetized using Fe3O4 NPs in a basic solution of FeCl2·4H2O and FeCl3·6H2O. Fe3O4@boehmite NPs have advantages of both boehmite nanoparticles and Fe3O4 magnetic materials. Magnetic boehmite nanoparticles have been characterized by various techniques such as TEM, SEM, EDS, WDX, ICP, FT-IR, Raman, XRD and VSM. SEM and TEM images confirmed that particles size are less than 50 nm in diameter with a cubic orthorhombic structure. Then, Fe3O4@boehmite NPs were applied as a homoselective, highly efficient, cheap, biocompatibility, heterogeneous and magnetically recoverable nanocatalyst in the synthesis of 5-substituted 1H-tetrazole derivatives. Fe3O4@boehmite NPs can be recycled for several runs in the synthesis of tetrazoles. Also, all tetrazoles were isolated in high yields, which reveals high activity of Fe3O4@boehmite NPs in the synthesis of tetrazole derivatives. Fe3O4@boehmite NPs shows a good homoselectivity in synthesis of 5-substituted 1H-tetrazole derivatives.

Recent developments in silver nanoparticles utilized for cancer treatment and diagnosis: a patent review

Nanotheranostics is a young but rapidly expanding science that incorporates elements of therapy and diagnostics in a unique and miniscule area of research. The potential to combine diagnostic and therapeutic abilities inside a complete unit opens up interesting possibilities for innovative biomedical research. Silver-based nanoparticles, for instance, are widely utilized as pharmacological and biomedical imaging molecules, and hence offer a lot of potential for the development of versatile targeted therapy compositions. These nanoparticles have been used for cancer diagnosis and cancer treatments recently. We evaluate major innovations based on silver nanotheranostics technologies in this review paper, with an emphasis on cancer treatment implications. The present review covers papers, from 2010 to 2020.

Magnetically Recoverable Silica-Decorated Ferromagnetic-Nanoceria Nanocatalysts and Their Use with O- and N-Butyloxycarbonylation Reaction via Solvent-Free Condition

Silica-decorated ferrite nanoparticles, a new kind, coated with ceric ammonium nitrate (CAN), have been prepared successfully by simple coprecipitation techniques. Powder X-ray diffraction spectroscopy (PXRD), Fourier transform-infrared spectroscopy (FT-IR), field emission-scanning electron microscope (FE-SEM), wavelength-dispersive X-ray spectroscopy (WDX), energy-dispersive spectroscopy (EDS), inductive coupled plasma-optical emission spectroscopy (ICP-OES), and thermogravimetric analysis (TGA) techniques were used to characterize these nanoparticles. The catalysts are further studied for catalytic activity in solvent-free conditions. Importantly, these nanoparticles have been collected from the reaction mixture using an external magnet and recycled up to minimum of 15 cycles with no substantial loss of catalytic characteristics.

First-principles study on structural, electronic, magnetic and thermodynamic properties of lithium ferrite LiFe5O8

Lithium ferrite, LiFe₅O₈ (LFO), has attracted great attention for various applications, and there has been extensive experimental studies on its material properties and applications. However, no systematic theoretical study has yet been reported, so understanding of its material properties at the atomic scale is still required. In this work, we present a comprehensive investigation into the structural, electronic, magnetic and thermodynamic properties of LFO using first-principles calculations. We demonstrate that the ordered α-phase with ferrimagnetic spin configuration is energetically favourable among various crystalline phases with different magnetic configurations. By applying the DFT + U approach with U = 4 eV, we reproduce the lattice constant, band gap energy, and total magnetization in good agreement with experiments, emphasizing the importance of considering strong correlation and spin-polarization effects originating from the 3d states of Fe atoms. We calculated the phonon dispersions of LFO with ferrimagnetic and non-magnetic states, and subsequently evaluated the Gibbs free energy differences between the two states, plotting the P–T diagram for thermodynamic stability of the ferrimagnetic against non-magnetic state. From the P–T diagram, the Curie temperature is found to be ∼925 K at the normal condition and gradually increase with increasing pressure. Our calculations explain the experimental observations for material properties of LFO, providing a comprehensive understanding of the underlying mechanism and useful guidance for enhancing performance of LFO-based devices.

We systematically investigate the material properties of lithium ferrite LiFe₅O₈ – structural, magnetic, electronic, lattice vibrational properties and thermodynamic stability – using density functional theory calculations.

Recyclable magnetically retrievable nanocatalysts for C–heteroatom bond formation reactions

During recent years, magnetic separation has proven to be a highly indispensable and sustainable tool for facile separation of catalysts from the reaction medium with the aid of only an external magnetic force that precludes the requirement of energy intensive, solvent based centrifugation or filtration techniques. Extensive research in the area of catalysis has clearly divulged that while designing any catalyst, the foremost features that need to be paid due attention to include high activity, ready recoverability and good reusability. Fortunately, the magnetic nanocatalysts involving a superparamagnetic core material that could comprise of iron oxides such as magnetite, maghemite or hematite or mixed ferrites (CoFe2O4, CuFe2O4) have offered bright prospects of designing the ideal catalysts by proving their efficacy as strong support material that could be further engineered with various tools of nanotechnology and efficiently catalyze various C–heterobond formation reactions. This chapter provides succinct overview of all the approaches utilized for fabricating different types of magnetic nanoparticles and strategies adopted for imparting them durability. The prime forte however remains to exclusively showcase the applications of the various types of magnetic nanocatalysts in C–O, C–N, C–S and miscellaneous (C–Se, C–Te) bond formation reactions which are anticipated to benefit the synthetic community on a broad spectrum by helping them rationalize and analyze the key features that need to be taken into account, while developing these magical nanostructured catalytic systems for boosting the green bond formation reactions/transformations.

Cucurbit[6]uril-Supported Fe3O4 Magnetic Nanoparticles Catalyzed Green and Sustainable Synthesis of 2-Substituted Benzimidazoles via Acceptorless Dehydrogenative Coupling

A new composite, cucurbit[6]uril (CB[6])-supported magnetic nanoparticles, Fe3O4-CB[6], was synthesized via a co-precipitation method in air and fully characterized by Fourier transform infrared spectroscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, thermogravimetric analysis, inductively coupled plasma-mass spectrometry, and vibrating sample magnetometry techniques. It has been found to be a highly efficient, economic, and sustainable heterogeneous catalyst and has been employed for the first time for the synthesis of a series of biologically important 2-substituted benzimidazoles from various benzyl alcohols and 1,2-diaminobenzenes under solvent-free conditions via acceptorless dehydrogenative coupling to afford the corresponding products in good to excellent yields (68-94%). The magnetic nature of the nanocomposite facilitates the facile recovery of the catalyst from the reaction mixture by an external magnet. The catalyst can be reused up to five times with negligible loss in its catalytic activity. All the isolated products were characterized by 1H and 13C{1H} NMR spectroscopy.

A controllable one-pot hydrothermal synthesis of spherical cobalt ferrite nanoparticles: synthesis, characterization, and optical properties

We herein report the controllable synthesis of spherical cobalt ferrite nanoparticles with average crystallite size in the range of 3.6–12.9 nm using a facile, eco-friendly, hydrothermal method. The hydrothermal treatment was carried out by utilizing cobalt nitrate, ferric nitrate, and ammonium hydroxide in the presence and absence of Arabic gum as a surfactant agent. The purity and crystallinity of the products were tuned by varying reaction conditions such as reaction time (0.5–8 h), reaction temperature (120–180 °C), percentage of ethylene glycol (0–100% (v/v)), pH (8–9.6), and amount of Arabic gum (0–2 g). We characterized the prepared products using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR), high-resolution transmission electron microscopy (HR-TEM), energy-dispersive X-ray spectroscopy analysis (EDS), selected area electron diffraction (SAED) patterns, and UV-visible diffuse reflectance spectra (DRS). The optimal hydrothermal treatment was performed at 180 °C and pH 9.6 for 4 h in aqueous media. The results also revealed that the as-prepared spinel cobalt ferrite nanoparticles have an estimated optical band gap energy in the range of ca. 1.6–1.9 eV, indicating the semiconducting characteristics of the products.

A controllable synthesis of spherical cobalt ferrite nanoparticles with average crystallite size in the range of 3.6–12.9 nm using a facile, eco-friendly, hydrothermal method.