Incorporating heterogeneous lacunary Keggin anions as efficient catalysts for solvent-free cyanosilylation of aldehydes and ketones

Malmir, Masoumeh; Heravi, Majid M.; Yekke-Ghasemi, Zahra; Mirzaei, Masoud

doi:10.1038/s41598-022-15831-1

Cited by 30 publications

(10 citation statements)

References 60 publications

(58 reference statements)

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“…The cell parameters of 1 were a = b = c = 21.636 Å (α = β = γ = 90°), with a volume V = 10,633.5 Å 3 and density, D calc (D exp ) = 3.8774 (3.8658) g cm −3 , while for 4 , a = b = c = 22.191 Å (α = β = γ = 90°) was found, with a volume V = 10,928 Å 3 and density, D calc (D exp ) = 3.8774 (3.8658) g cm −3 . The increase in cell parameters for complex 4 compared to complex 1 is due to the increasing number of crystallisation water molecules in lattice 4 [ 31 , 37 , 38 , 39 ]. For complexes 1 and 4 , the first diffraction peak was very intense compared to the others because crystallites were oriented preferentially in the sample [ 27 , 40 ].…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Characterisation of Monolacunary Keggin Monovanado-deca-tungstophosphate and Its Complexes with Transition Metal Cations

et al. 2023

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Five new complexes with metal cations (Mn2+, Fe3+, Co2+, Ni2+, and Cu2+) of monolacunary Keggin monovanado-deca-tungstophosphate, K8[PVW10O39]·15H2O, have been synthesised. The molar ratio of the combination between metal cations and K8[PVW10O39]·15H2O has been established to be 1:1, and its general molecular formulas were found to be: Kn[MPVW10O39(H2O)]·xH2O (n = 5 for M = Fe3+ and n = 6 for M = Mn2+, Co2+, Ni2+, and Cu2+). Optimal conditions for complexes’ synthesis (pH, temperature, and reaction time) have been determined. The characterisation of K8[PVW10O39]·15H2O and of its compounds Kn[MPVW10O39(H2O)]·xH2O have been performed using AAS, TG-DTA-DTG, UV-VIS, IR, Raman, and powder XRD methods. In UV spectra, two maximums of absorption were obtained, at 200 and 250 nm, characteristic of Keggin polycondensate compounds. The coordination of cations Ni2+, Co2+, and Cu2+ through oxygen atoms from K8[PVW10O39]·15H2O in an octahedron system has been reflected with VIS spectroscopy. All these methods have proved the compositions and structures of K8[PVW10O39]·15H2O and Kn[MPVW10O39(H2O)]·xH2O, their similarity with other vanadotungstophosphates, and their achievements in the Keggin class. Additionally, all analysis methods have shown an increase in the degree of structural symmetry and the thermal stability of a polyoxoanion complex after attaching metal cations compared to the monolacunary, K8[PVW10O39]·15H2O.

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Section: Resultsmentioning

confidence: 99%

Synthesis and Characterisation of Monolacunary Keggin Monovanado-deca-tungstophosphate and Its Complexes with Transition Metal Cations

et al. 2023

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“…In line with the ongoing research and growing interest in the synthesis and application of heterogeneous catalysts as well as the pursuit of environmentally friendly approaches to enhance chemical reactions, [36][37][38][39][40][41][42][43][44] this study presents a novel method for synthesizing catalysts based on MOFs. The catalyst are prepared by conjucating cyanuric chloride (TCT) and imidazole (IMI) with aspartic acid, which is then decorated with Fe 3 O 4 .…”

Section: Introductionmentioning

confidence: 99%

Highly selective reduction of nitro compounds catalyzed by MOF‐derived glucose stabilized Fe₃O₄ under mild conditions

Bisafar,

Malmir,

Heravi

2023

J of Chemical Tech & Biotech

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BACKGROUNDToday, studies on the catalytic reduction of nitroarenes and dyes are of crucial because nitroarenes, especially 4‐nitrophenol (4‐NPh) and dyes, which are considered important pollutants in wastewater, can pose risks to humans. It is noteworthy that amines are known as valuable intermediates in many industries, therefore, providing an efficient method to achieve these compounds is necessary to protect the environment. In this project, a magnetic MOFs‐based catalyst (containing Cu species as an active site) was found to offer a unique and cost‐effective route for the catalytic reduction of nitroarene and organic dyes.RESULTSIn this study, a novel magnetic catalyst, Fe3O4@glu/Cu‐TAZ‐IMI, based on MOF was synthesized. The core‐shell structure of Fe3O4@glu, functionalized with aspartic acid with TAZ‐IMI and Cu(OAc)2, resulted in the formation of magnetic MOF structure. The structure of this new nanocomposite was identified by X‐ray diffraction (XRD), Fourier Transform Infrared Spectrometer (FTIR), Brunauer–Emmett–Teller (BET), Scanning electron microscopy/energy dispersive X‐ray (SEM/EDX), Thermogravimetric analysis (TGA), High‐resolution transmission electron microscopy (HRTEM), Value stream mapping (VSM), Raman spectroscopy and Inductively coupled plasma‐optical emission spectrometry (ICP‐OES). The catalytic performance of the synthesized catalyst was evaluated for the reduction of nitro compounds and organic dyes, and the results were validated by Gas chromatography‐mass (GC–MS) and ultraviolet light (UV–Vis) spectroscopy. Moreover, the rate constants for the reduction of 4‐NPh, Congo red (CR), and Methylene blue (MB) followed pseudo first‐order kinetics model, which calculated values of 0.31 min−1, 0.355 min−1 and 0.044 s−1, respectively.CONCLUSIONThe catalytic efficacy of Fe3O4@glu/Cu‐TAZ‐IMI catalyst remained intact during the reduction of nitroarenes and organic dyes in aqueous and mild conditions. The findings demonstrate that this novel heterogeneous mesoporous catalyst exhibits exceptional catalytic activity and remarkable stability towards reduction reactions. Moreover, owning to its thermal and structural stability, the catalyst could be easily magnetically separated, recovered, and reused for up to 10 consecutive cycles without experiencing significant activity decline, effectively preventing the depletion of copper species from its structure. © 2023 Society of Chemical Industry.

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“…In recent decades, polynuclear coordination polymers have garnered significant attention due to their intriguing architectures and fascinating physical and chemical properties. − By integrating polyoxometalates (POMs) into this system, POM-based polynuclear coordination polymers can harness their combined benefits, which not only possess diverse structures but also display exceptional potential for various applications in the fields such as optics, catalysis, medicine, and particularly magnetism and proton conduction. − …”

Section: Introductionmentioning

confidence: 99%

N–N-Bridged Polynuclear POM-Based Coordination Polymers Based on a V-Type Ligand: Proton Conduction and Magnetism

Lun,

Zhang,

Sun

et al. 2023

Inorg. Chem.

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The construction of polyoxometalate (POM)-based coordination polymers, in the presence of a nitrogen heterocyclic ligand, is intriguing due to the potential for obtaining diverse structures. These structures exhibit extensive application possibilities in the fields of proton conductivity and magnetism. Herein, four new POM-based polynuclear coordination polymers with the formulas of {[Fe 2 (btb) 4) have been prepared using the V-type 1,3-bis(4H-1,2,4-triazole-4-yl)benzene (btb) ligand. Compounds 1 and 2 feature similar twodimensional (2D) structures, derived from the binuclear Fe 2 N 6 and Cd 2 N 4 subunits connected by tridentate btb ligands. Meanwhile, in compound 3, hexanuclear Co 6 (OH) 4 units are bound by quadridentate btb ligands forming a 2D layer with the same 4-c sql topology simplification as compounds 1 and 2. In compound 1, Keggin-type polyoxoanions are monodentate-coordinated to metal ions and suspended on the 2D structure, while, in compounds 2 and 3, they act as discrete counterions residing in the interstitial spaces between two adjacent layers, thereby extending the 2D structures into 3D structures through hydrogen bonding interactions. In compound 4, trinuclear Cu 3 (OH) subunits are further constructed into a 3D framework through cooperation with four tridentate and quadridentate btb ligands as well as Strandberg-type anions. Furthermore, the proton conduction of the four compounds has been investigated. They display high proton conductivities at 358 K and 98% RH with powdered samples, which are 1.26 × 10 −3 , 1.24 × 10 −3 , 3.24 × 10 −4 , and 2.57 × 10 −4 S cm −1 , respectively. Interestingly, by mixing with Nafion, the composite membranes of compounds 2 and 4 exhibit enhanced proton conductivities, measuring at 4.87 × 10 −2 and 1.28 × 10 −2 S cm −1 , respectively, at 358 K and 98% RH, which suggests excellent potential for applications. In addition, compounds 1, 3, and 4 display antiferromagnetic behaviors due to similar magnetic interactions. This work can provide research insights into the assembly of 2D POM-based coordination polymers with nitrogen heterocyclic ligands and Keggin-type POMs and further promote their research progress in proton conduction.

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Incorporating heterogeneous lacunary Keggin anions as efficient catalysts for solvent-free cyanosilylation of aldehydes and ketones

Cited by 30 publications

References 60 publications

Synthesis and Characterisation of Monolacunary Keggin Monovanado-deca-tungstophosphate and Its Complexes with Transition Metal Cations

Synthesis and Characterisation of Monolacunary Keggin Monovanado-deca-tungstophosphate and Its Complexes with Transition Metal Cations

Highly selective reduction of nitro compounds catalyzed by MOF‐derived glucose stabilized Fe₃O₄ under mild conditions

N–N-Bridged Polynuclear POM-Based Coordination Polymers Based on a V-Type Ligand: Proton Conduction and Magnetism

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Incorporating heterogeneous lacunary Keggin anions as efficient catalysts for solvent-free cyanosilylation of aldehydes and ketones

Cited by 30 publications

References 60 publications

Synthesis and Characterisation of Monolacunary Keggin Monovanado-deca-tungstophosphate and Its Complexes with Transition Metal Cations

Synthesis and Characterisation of Monolacunary Keggin Monovanado-deca-tungstophosphate and Its Complexes with Transition Metal Cations

Highly selective reduction of nitro compounds catalyzed by MOF‐derived glucose stabilized Fe3O4 under mild conditions

N–N-Bridged Polynuclear POM-Based Coordination Polymers Based on a V-Type Ligand: Proton Conduction and Magnetism

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Highly selective reduction of nitro compounds catalyzed by MOF‐derived glucose stabilized Fe₃O₄ under mild conditions