Selective oxidation of ethylbenzene to acetophenone over Cr(III) Schiff base complex intercalated into layered double hydroxide

Kirar, Jagat Singh; Khare, Savita

doi:10.1002/aoc.4408

Cited by 18 publications

(15 citation statements)

References 44 publications

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“…One of the most often used anionexchange families is the layered double hydroxides (LDHs) in which the positive charges of the double (M 2+ and M 3+ ) metal hydroxide layers were compensated by interlamellar solvated anions. 20,21 These interlayer anions can be further exchanged with more or less difficulties by different type of anions such as amino carboxylates, 22,23 polyoxometallates, 24 Schiff-base complexes, 25 polymeric anions, 26 DNA, 27 etc. In parallel to this process, surface adsorption of the guest molecules could also occur.…”

Section: Introductionmentioning

confidence: 99%

Distinguishing Anionic Species That Are Intercalated in Layered Double Hydroxides from Those Bound to Their Surface: A Comparative IR Study

et al. 2022

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Guest molecules in layered double hydroxides (LDHs) may be located both on the surface and in the interlayer gallery. In this work, a comparative study of various IR spectroscopic methods coupled with X-ray diffraction (XRD) is presented, which makes it possible to distinguish between the two possibilities. During the experimental work, first, CaAl-LDHs intercalated with nitrate/carbonate ions were transformed to d-gluconate- and benzoate-containing solids. Depending on the initial interlayer ion, the organic molecules may end up between the layers and/or on the surface of the LDH. The IR spectra of the specimens were recorded by using four different techniques, which are different in their penetration depth (photoacoustic spectroscopy (PAS), attenuated total reflectance (ATR), diffuse reflectance IR spectroscopy (DRIFTS), and wide angle diffuse reflectance (WA-DRIFTS)). By comparing the spectra obtained, the anionic species that are surface adsorbed to LDHs were proven to be distinguishable from those intercalated in the interlayer gallery. PAS spectra are shown to provide information about interlamellar and bulk compounds. The screening of the surface species could be performed using the WA-DRIFTS technique, while ATR and DRIFTS are capable of detecting both the surface and the bulk anions residing in the top few layers.

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Section: Introductionmentioning

confidence: 99%

Distinguishing Anionic Species That Are Intercalated in Layered Double Hydroxides from Those Bound to Their Surface: A Comparative IR Study

et al. 2022

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“…immobilized metalloporphyrins and their catalysis systems [31][32][33][34][35] adapting to the cleaner production process. However, the resulting yields (acetophenone and phenylethanol (ONE + OL), less than 25%) were lower than those obtained from the catalytic systems above [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] . In addition, RSM was also seldom used in the catalytic field of metalloporphyrins [14][15][16][17]19,20,[31][32][33][34][35] .…”

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confidence: 74%

Full use of factors promoting catalytic performance of chitosan supported manganese porphyrin

Huang

Wang

et al. 2020

Sci Rep

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in order to make full use of the impact of internal and external factors on the performance of title catalyst for ethyl benzene oxidation, the key internal influencing factors on the catalytic performance were modulated by coordinating and grafting manganese porphyrin to mesoporous and macroporous chitosan, and the important external factors (i.e. oxidation reaction conditions) were optimized using Response Surface Methodology. Under the Response Surface Methodology optimized oxidation reaction conditions (176.56 °C, 0.59 MPa, and 0.25 mg amount of manganese porphyrin), the catalyst could be used at least five times. The ethyl benzene conversion, catalyst turnover numbers, and yields reached up to 51.2%, 4.37 × 10 6 and 36.4% in average, respectively. Compared with the other optimized oxidation reaction conditions, the corresponding values increased 17%, 26% and 53%. Relative to the manganese porphyrin, the catalytic performance and efficiency of the immobilized catalyst had notably increased. High-efficiency and high-selectivity oxidation of ethyl benzene (EB) has been still paid a great attention 1-6. There were so many advanced catalysts and catalytic ethyl benzene oxidation technologies 1-25 , some of which could even offer high yields of products 1-6. However, up to date the oxidation techniques used are not very satisfactory yet: There were mainly lack of cleaner production techniques, for examples, O 2 was not used as oxidant, toxic solvents were used, some energy saving and emission reduction had not been done, and so on. Therefore, the catalyst preparation 21-25 , the catalytic oxidation system and the oxidation conditions 7-20 , which are satisfactorily meeting to the cleaner production process should be comprehensively considered. Based on the above considerations, the internal influencing factors on the catalytic performance of catalyst should be further reasonably tuned, and the external influencing factors should be optimized via Response Surface Methodology (RSM). Because RSM has been successfully used in other catalysis fields: It has been used for optimization of the various reaction conditions and prediction of interactions between the influencing reaction condition parameters based on constructing a suitable model, evaluating the effects of key factors and searching the optimum reaction conditions. The better catalysis responses have achieved 26-29. These considerations and the various optimizations above will probably bring the advanced catalysis techniques 7-25 forwards better catalytic results and excellent various applications in practical chemistry industry. Due to a great deal of attention to the environmental issues, for modern companies which are manufacturing the products of acetophenone and phenylethanol via ethyl benzene oxidation, a set of strict modern technique of cleaner production has to be requested. Under the preconditions, the immobilized metalloporphyrins and their catalysis systems, which are usually not added any additives, co-reductants, and solvents, but oxygen molecules...

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“…It was found that the conversion of toluene in the presence of solvents was decreased due to the blocking of active sites by solvent molecules or that there could be a diffusion rivalry between solvent and substrate molecules for active sites. [33]…”

Section: Effect Of Various Solventsmentioning

confidence: 99%

“…[30] We have previously studied heterogeneous oxidation catalysts for aromatic hydrocarbons assisted by transition metal. [31][32][33][34] Mn(III) and Fe(III) Schiff base complexes supported on layered double hydroxide have been recently tested for the oxidation of toluene. [35] The present study will focus on the catalytic oxidation of toluene over LDH-supported heterogeneous catalysts, LDH-[NAPABA-M] {where M = Cu(II), and Co(II)} with tert-butyl hydroperoxide as an oxidant under solvent-free conditions.…”

Section: Introductionmentioning

confidence: 99%

Cu(II) and Co(II) Schiff‐Base Complexes Immobilized on Layered Double Hydroxide: Synthesis, Characterizations, DFT Calculations and Catalytic Activity

Kirar¹,

Khare

Tiwari

2021

ChemistrySelect

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In this study, we are reporting the synthesis, characterization, theoretical studies, and catalytic activity of Cu(II), and Co(II) Schiff base complexes immobilized on layered double hydroxide abbreviated as LDH‐[NAPABA‐M] {where M=Cu(II), and Co(II)}. The Schiff base ligand (E)‐4‐((2‐hydroxynaphthalen‐1‐yl)methyleneamino)benzoic acid have been synthesized from the condensation of 2‐hydroxy‐1‐naphthaldehyde and 4‐amino benzoic acid. The complexes were characterized using Inductively coupled plasma‐Atomic emission spectrometry (ICP‐ AES), X‐Ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive X‐Ray (EDX), Fourier transform infrared (FTIR), Electron paramagnetic resonance (EPR) spectroscopy, Thermogravimetric analysis (TGA) etc. and the geometry of the ligand has been calculated using Density Functional Theory (DFT) calculations at the B3LYP/6‐31G level of theory. The catalytic activity of synthesized catalysts was tested for toluene oxidation with tert‐butyl hydroperoxide under solvent‐free conditions. The LDH‐[NAPABA‐Cu(II)] catalyst was recycled up to seven cycles. Hot filtration experiments demonstrate that the catalyst was heterogeneous in nature and stable.

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Selective oxidation of ethylbenzene to acetophenone over Cr(III) Schiff base complex intercalated into layered double hydroxide

Cited by 18 publications

References 44 publications

Distinguishing Anionic Species That Are Intercalated in Layered Double Hydroxides from Those Bound to Their Surface: A Comparative IR Study

Distinguishing Anionic Species That Are Intercalated in Layered Double Hydroxides from Those Bound to Their Surface: A Comparative IR Study

Full use of factors promoting catalytic performance of chitosan supported manganese porphyrin

Cu(II) and Co(II) Schiff‐Base Complexes Immobilized on Layered Double Hydroxide: Synthesis, Characterizations, DFT Calculations and Catalytic Activity

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