6287-86-1Relevant academic research and scientific papers
Photocatalytic degradation of anthracene in aqueous dispersion of metal oxides nanoparticles: Effect of different parameters
Sliem, Mahmoud A.,Salim, Ahmed Youssef,Mohamed, Gehad Genidy
, p. 327 - 335 (2019)
Contamination with anthracene, as one of polycyclic aromatic hydrocarbons (PAHs), was considered as an important health issue due to its carcinogenic and mutagenic activity. In this paper, we focused on the photocatalytic degradation of anthracene in different media and in presence of various photocatalysts. Zinc oxide nanoparticles (ZnO NPs) and nickel oxide nanoparticles (NiO NPs) were prepared and utilized as efficient photocatalysts to convert anthracene into safer compounds. The as-prepared photocatalysts were characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM) and UV-VIS spectroscopy. The factors affecting the efficiency of photocatalytic degradation, including irradiation time, loading catalyst doses, pH value and H2O2 as an oxidizing agent, were investigated. The optimum photocatalytic degradation of 23 mg/L anthracene in different media was carried out at pH 7.2 with loading catalyst dose of 55.6 mg/L. In case of anthracene emulsion solution, a faster photochemical kinetic was observed in presence of ZnO NPs and more than 90% of photocatalytic degradation percentage was reached in 230 min. However, in case of anthracene aqueous solution and in presence of ZnO NPs/H2O2, a degradation efficiency of 84% was obtained within 50 min. The byproducts of 4- formyl-benzoic acid ethyl ester (98.23%) and 1,2-Benzenedicarboxylic acid, isopropyl methyl ester (0.85%)) were detected by gas chromatography-mass spectrometry (GC–MS). The kinetic studies were achieved and revealed that the photocatalytic degradation process obeyed a Langmuir–Hinshelwood model and followed a pseudo-first order rate expression.
Modular Synthesis of trans-A2B2-Porphyrins with Terminal Esters: Systematically Extending the Scope of Linear Linkers for Porphyrin-Based MOFs
Marschner, Stefan M.,Haldar, Ritesh,Fuhr, Olaf,W?ll, Christof,Br?se, Stefan
, p. 1390 - 1401 (2020/12/14)
Differently functionalized porphyrin linkers represent the key compounds for the syntheses of new porphyrin-based metal–organic frameworks (MOFs), which have gathered great interest within the last two decades. Herein we report the synthesis of a large range of 5,15-bis(4-ethoxycarbonylphenyl)porphyrin derivatives, through Suzuki and Sonogashira cross-coupling reactions of an easily accessible corresponding meso-dibrominated trans-A2B2-porphyrin with commercially available boronic acids or terminal alkynes. The resulting porphyrins were fully characterized through NMR, MS, and IR spectroscopy and systematically investigated through UV/Vis absorption. Finally, selected structures were saponified to the corresponding carboxylic acids and subsequently proven to be suitable for the synthesis of surface-anchored MOF thin films.
A Synthetic Strategy for Cofacial Porphyrin-Based Homo- and Heterobimetallic Complexes
Schissler, Christoph,Schneider, Erik K.,Felker, Benjamin,Weis, Patrick,Nieger, Martin,Kappes, Manfred M.,Br?se, Stefan
supporting information, p. 3047 - 3054 (2021/01/20)
We present a straightforward and generally applicable synthesis route for cofacially linked homo- and heterobimetallic porphyrin complexes. The protocol allows the synthesis of unsymmetrical aryl-based meso-meso as well as β-meso-linked porphyrins. Our method significantly increases the overall yield for the published compound known as o-phenylene-bisporphyrin (OBBP) by a factor of 6.8. Besides the synthesis of 16 novel homobimetallic complexes containing MnIII, FeIII, NiII, CuII, ZnII, and PdII, we achieved the first single-crystal X-ray structure of an unsymmetrical cofacial benzene-linked porphyrin dimer containing both planar-chiral enantiomers of a NiII2 complex. Additionally, this new methodology allows access to heterobimetallic complexes such as the FeIII-NiII containing carbon monoxide dehydrogenase active site analogue. The isolated species were investigated by various techniques, including ion mobility spectrometry, DFT calculations, and UV/Vis spectroscopy. This allowed us to probe the influence of interplane distance on Soret band splitting.
Nitrile Synthesis by Aerobic Oxidation of Primary Amines and in situ Generated Imines from Aldehydes and Ammonium Salt with Grubbs Catalyst
Utsumi, Tatsuki,Noda, Kenta,Kawauchi, Daichi,Ueda, Hirofumi,Tokuyama, Hidetoshi
, p. 3583 - 3588 (2020/08/05)
Herein, a Grubbs-catalyzed route for the synthesis of nitriles via the aerobic oxidation of primary amines is reported. This reaction accommodates a variety of substrates, including simple primary amines, sterically hindered β,β-disubstituted amines, allylamine, benzylamines, and α-amino esters. Reaction compatibility with various functionalities is also noted, particularly with alkenes, alkynes, halogens, esters, silyl ethers, and free hydroxyl groups. The nitriles were also synthesized via the oxidation of imines generated from aldehydes and NH4OAc in situ. (Figure presented.).
Method for reducing carboxylic acid compound into aldehyde
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Paragraph 0044-0047, (2020/02/27)
The invention discloses a method for reducing a carboxylic acid compound into aldehyde. In a nitrogen atmosphere, in an organic solvent, a ligand/Cu catalyst, the carboxylic acid compound, an anhydride compound and hydrosilane are added by a one-pot method, a reaction is performed under the condition of the temperature of 20-120 DEG C for 2-20 h, after the reaction is completed, quenching and column chromatography separation are performed to obtain the product. The carboxylic acid compound can be successfully converted into aldehyde through one-pot reaction, especially unsaturated carboxylic acid can be reduced, and the reaction yield is generally relatively high. Compared with the prior art, the method has the outstanding advantages that the cheap copper salt is used as a catalyst, so that the experiment cost is greatly reduced. Meanwhile, the used method enlarges the application range of the reaction substrate, improves the compatibility of functional groups, and provides a new synthesis way for reducing the carboxylic acid compound into aldehyde.
Construction of Esters through Sulfuryl Fluoride (SO 2 F 2) Mediated Dehydrative Coupling of Carboxylic Acids with Alcohols at Room Temperature
Qin, Hua-Li,S Alharbi, Njud,Wang, Shi-Meng
, p. 3901 - 3907 (2019/10/11)
A facile method for the construction of esters through dehydrative coupling of carboxylic acids with alcohols is developed. The reactions are mediated by sulfuryl fluoride (SO 2 F 2) at room temperature and proceed with high efficiency. The method has several advantages including broad substrate scope, mild conditions, excellent functional group compatibility and affords high yields, even on gram scale.
Method for synthesizing aromatic aldehyde through iron catalyzed oxidation allyl aromatic compound
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Paragraph 0111-0113; 0151, (2019/06/27)
The invention discloses a method for synthesizing aromatic aldehyde through an iron catalyzed oxidation allyl aromatic compound. According to the specific method, under the promotion effect of hydrogen silane, with air or oxygen as the oxidant, the aromatic aldehyde compound is synthesized through the iron catalyzed oxidation allyl aromatic compound, the reaction temperature is 20-150 DEG C, and the time is 0.25-60 h. The method has the advantages that a catalyst source is wide, the price is low and the environment is protected; an oxidant source is wide, the price is low and no waste is generated; the reaction conditions are mild, selectivity is high and the yield is high; a substrate source is wide and stable; a substrate functional group is high in compatibility and a substrate is widein application range; complicated small molecules are compatible and can be well converted into aldehyde. The target product separation yield can reach up to 96% under the optimized reaction conditions.
Continuous-flow Synthesis of Aryl Aldehydes by Pd-catalyzed Formylation of Aryl Bromides Using Carbon Monoxide and Hydrogen
Hone, Christopher A.,Lopatka, Pavol,Munday, Rachel,O'Kearney-McMullan, Anne,Kappe, C. Oliver
, p. 326 - 337 (2018/11/23)
A continuous-flow protocol utilizing syngas (CO and H2) was developed for the palladium-catalyzed reductive carbonylation of (hetero)aryl bromides to their corresponding (hetero)aryl aldehydes. The optimization of temperature, pressure, catalyst and ligand loading, and residence time resulted in process-intensified flow conditions for the transformation. In addition, a key benefit of investigating the reaction in flow is the ability to precisely control the CO-to-H2 stoichiometric ratio, which was identified as having a critical influence on yield. The protocol proceeds with low catalyst and ligand loadings: palladium acetate (1 mol % or below) and cataCXium A (3 mol % or below). A variety of (hetero)aryl bromides at a 3 mmol scale were converted to their corresponding (hetero)aryl aldehydes at 12 bar pressure (CO/H2=1:3) and 120 °C reaction temperature within 45 min residence time to afford products mostly in good-to-excellent yields (17 examples). In particular, a successful scale-up was achieved over 415 min operation time for the reductive carbonylation of 2-bromo-6-methoxynaphthalene to synthesize 3.8 g of 6-methoxy-2-naphthaldehyde in 85 % isolated yield. Studies were conducted to understand catalyst decomposition within the reactor by using inductively coupled plasma–mass spectrometry (ICP–MS) analysis. The palladium could easily be recovered using an aqueous nitric acid wash post reaction. Mechanistic aspects and the scope of the transformation are discussed.
Bridging the Green Gap: Metal–Organic Framework Heteromultilayers Assembled from Porphyrinic Linkers Identified by Using Computational Screening
Haldar, Ritesh,Batra, Kamal,Marschner, Stefan Michael,Kuc, Agnieszka B.,Zahn, Stefan,Fischer, Roland A.,Br?se, Stefan,Heine, Thomas,W?ll, Christof
supporting information, p. 7847 - 7851 (2019/05/22)
In organic photovoltaics, porphyrins (PPs) are among the most promising compounds owing to their large absorption cross-section, wide spectral range, and stability. Nevertheless, a precise adjustment of absorption band positions to reach a full coverage of the so-called green gap has not been achieved yet. We demonstrate that a tuning of the PP Q- and Soret bands can be carried out by using a computational approach for which substitution patterns are optimized in silico. The most promising candidate structures were then synthesized. The experimental UV/Vis data for the solvated compounds were in excellent agreement with the theoretical predictions. By attaching further functionalities, which allow the use of PP chromophores as linkers for the assembly of metal-organic frameworks (MOFs), we were able to exploit packing effects resulting in pronounced redshifts, which allowed further optimization of the photophysical properties of PP assemblies. Finally, we use a layer-by-layer method to assemble the PP linkers into surface-mounted MOFs (SURMOFs), thus obtaining high optical quality, homogeneous and crystalline multilayer films. Experimental results are in full accord with the calculations, demonstrating the huge potential of computational screening methods in tailoring MOF and SURMOF photophysical properties.
Facile, highly efficient and environmentally friendly transesterification mediated by platinum dioxide and nickel oxide under essentially neutral conditions
Teng, Binhao,Shi, Jiangong,Yao, Chunsuo
, p. 2465 - 2471 (2018/06/11)
A practical, facile and highly efficient transesterification reaction under essentially neutral conditions was achieved using platinum dioxide (PtO2) or PtO2/nickel oxide (NiO) as the catalyst. A number of esters and alcohols that contain various functional groups were employed. Good to excellent yields were obtained for different aromatic or aliphatic starting materials. The Pt-alcohol intermediate generated in situ facilitated the exchange of low-alcohol esters to high-alcohol esters.
