Zeolite encapsulated Ni(<scp>ii</scp>) Schiff-base complexes: improved catalysis and site isolation

Kumari, Susheela; Ray, Saumi

doi:10.1039/d0nj01590c

Cited by 17 publications

(16 citation statements)

References 40 publications

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“…The presence of Ni 2+ was confirmed by the Ni2p3/2 and Ni2p1/2 peaks appearing at binding energies of 855.7 and 873.5 eV, respectively, for Catalyst 1 (Figure 5 (b)), along with two satellite broad peaks at the binding energies of 861.6 and 879.7 eV, respectively. This indicates that the environment around the metal center is disturbed [10] . The N1s peaks were observed at 399.4 eV for Catalyst 1 was ascribed to imine or amide groups (C=N).…”

Section: Resultsmentioning

confidence: 97%

“…This indicates that the environment around the metal center is disturbed. [10] The N1s peaks were observed at 399.4 eV for Catalyst 1 was ascribed to imine or amide groups (C=N). In the case of Catalyst 1, the lower steric hindrance of the bidentate ligand may afford the proximity between the Ni metal centers, resulting in the formation of a dimeric species.…”

Section: Chemistryselectmentioning

confidence: 97%

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Syntheses and Catalytic Behavior of Dendritic Macrocyclic Schiff‐Base Nickel (II) Complexes in Ethylene Oligomerization

et al. 2023

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The functionalized dendrimers play an important role in catalytic application. A dendritic Schiff base macrocyclic compound was designed and synthesized with the 1.0 generation dendrimer polyamidoamine (1.0G PAMAM) and terephthalaldehyde for ethylene oligomerization. The role of solvent in the synthesized process of dendritic macrocyclic Schiff base ligand was studied. Surprisingly, intermolecular or intramolecular cyclization occurred and formed bicyclic Schiff base ligand (Ligand 1) and polycyclic Schiff base ligand (Ligand 2). And their corresponding nickel complexes (Catalyst 1 and Catalyst 2) were also synthesized with NiCl2(DME) as material to be used for ethylene oligomerization. The effects of the reaction parameters and the chemical structure of the ligand on the catalytic behavior were investigated with methyl‐aluminoxane (MAO) as cocatalyst, and Catalyst 1 and Catalyst 2 displayed the high catalytic activity and the high selectivity for low‐carbon olefin in ethylene oligomerization. Catalyst 2 based on Ligand 2 had a higher catalytic activity of 9.12×104 g (mol Ni h)−1 in ethylene oligomerization because of large dendritic ring in the ligand for ethylene diffusion and mass transfer. Moreover, two synthesized nickel complexes based on dendritic macrocyclic Schiff base ligand had a higher catalytic activity compared with the corresponding dendritic salicylaldehydeimine nickel (II) catalyst.

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Section: Resultsmentioning

confidence: 97%

Section: Chemistryselectmentioning

confidence: 97%

Syntheses and Catalytic Behavior of Dendritic Macrocyclic Schiff‐Base Nickel (II) Complexes in Ethylene Oligomerization

et al. 2023

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“…It was found that there was a certain degree of metal coordination structure in the coating. The binding energies of the 2p3/2 and 2p1/2 Ni (II) peaks in Nickel(II) acetate tetrahydrate were 856.2 and 873.9 eV, respectively [ 35 , 36 ]. After coordination with the polymer, the binding energy decreased to 854.7 and 872.1 eV, respectively.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Characterization of Schiff Base Polymers via Metal Coordination and Its Application in Infrared Stealth Coating

Zong

et al. 2022

Polymers

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In order to reduce the infrared emissivity to meet the requirements of modern warfare for infrared stealth materials, we prepared the polymers containing Schiff base moieties using polyetheramine and 2,6-pyridinedicarboxaldehyde by solution polycondensation and coordinated with Ni2+, Cu2+, and Sm3+ ions to prepare organic coatings. The structure and the thermal and mechanical properties of the coatings were studied in detail. Meanwhile, the effect of the conductivity change of coordination polymers on infrared emissivity was studied systematically. The results showed the polymer coordinated with Sm3+ ions had the lowest energy band gap, which was 2.99 eV, and the best electrical conductivity of 3.54 × 10−4 S/cm compared with Ni2+ and Cu2+ coordination polymers. The infrared emissivity was the lowest in the 2–22 μm infrared waveband range, which reached 0.58, suggesting the polymers containing Schiff base moieties and their coordination polymers may have a great potential to be applied as infrared stealth materials in military applications.

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“…The 48 . Compared with the isolated nickel metal, which exhibited a Ni 0 (2p 3/2 ) binding energy (BE) of 853 eV, the ITQ-2supported nickel showed higher BEs (∼856 eV) for Ni 0 (2p 3/2 ) due to the electronic influence of the zeolite support 49 . It has been reported that interactions of metal clusters with oxygens in the zeolite framework gave rise to positive charges on the metal surface and higher BEs for the metal nanoclusters 50,51 .…”

Section: Physicochemical Properties Of the Ni/zeolite Materialsmentioning

confidence: 99%

Toward the production of renewable diesel over robust Ni nanoclusters highly dispersed on a two-dimensional zeolite

Pang

Yang

et al. 2023

NPG Asia Mater

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Deoxygenation of bioderived lipids into renewable transportation fuels is a promising route to decreasing the dependence on fossil sources. Ni-based catalysts are high performing and cost-effective in deoxygenation reactions but suffer from severe sintering and aggregation. Herein, a ligand-chelating impregnation method was used to prepare highly dispersed Ni nanoclusters on a two-dimensional (2D) ITQ-2 zeolite. Comprehensive characterization was utilized to monitor the changes in the organometallic precursors during activation and to investigate their impact on the dispersion of the Ni nanoclusters on the ITQ-2 zeolite. The high external surface area and abundant surface defects of the 2D support enhanced the dispersion and immobilization of the Ni nanoclusters and outperformed conventional zeolites. The protection of the Ni2+ cations by the organic ligand suppressed the aggregation of Ni species during the activation processes, thereby leading to the formation of uniformly distributed Ni nanoclusters on the ITQ-2 zeolite. Due to the highly dispersed Ni nanoclusters and immobilization on the 2D zeolite, the Ni/ITQ-2-co material prepared by the ligand-chelating impregnation approach showed outstanding activity and stability for conversions of stearic acid or palm oil to diesel range alkanes. This work provides a rational design and precise modulation of metal-based catalysts for the production of renewable diesel.

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Zeolite encapsulated Ni(ii) Schiff-base complexes: improved catalysis and site isolation

Abstract: Two series of zeolite encapsulated Ni(II) Schiff-base complexes e.g., {Ni(II) sal-1,2-phen and Ni(II) sal-1,3-phen series} have been synthesized in neat and encapsulated states and characterized by different characterization techniques...

Cited by 17 publications

References 40 publications

Syntheses and Catalytic Behavior of Dendritic Macrocyclic Schiff‐Base Nickel (II) Complexes in Ethylene Oligomerization

Syntheses and Catalytic Behavior of Dendritic Macrocyclic Schiff‐Base Nickel (II) Complexes in Ethylene Oligomerization

Synthesis and Characterization of Schiff Base Polymers via Metal Coordination and Its Application in Infrared Stealth Coating

Toward the production of renewable diesel over robust Ni nanoclusters highly dispersed on a two-dimensional zeolite

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