70851-51-3Relevant academic research and scientific papers
Synthesis and characterization of MgO nanoparticles supported on ionic liquid-based periodic mesoporous organosilica (MgO@PMO-IL) as a highly efficient and reusable nanocatalyst for the synthesis of novel spirooxindole-furan derivatives
Baharfar, Robabeh,Zareyee, Daryoush,Allahgholipour, Seyedeh Leila
, (2019)
The synthesis and catalytic application of a novel MgO containing periodic mesoporous organosilica with ionic liquid framework (MgO@PMO-IL) is described. The prepared MgO@PMO-IL was characterized by Fourier transform-infrared spectroscopy, N2 adsorption/desorption, transmission electron microscopy, field emission-scanning electron microscopy, thermogravimetric and inductively coupled plasma analyses. This nanocatalyst was successfully applied as a highly efficient and recoverable catalyst for the synthesis of novel spirooxindole-furan derivatives via the three-component reaction of 1,3-dicarbonyl compounds, N-phenacyl pyridinium salts and isatin derivatives. The products were achieved in high to excellent yields with a simple work-up procedure and short reaction times, and the catalyst could be recovered through a simple filtration process and successfully reused seven times without any significant decrease in its efficiency.
Versatile methods for the synthesis of Si(OR)3-functionalised imidazolium salts, potential precursors for heterogeneous NHC catalysts and composite materials
Cazin, Catherine S. J.,Veith, Michael,Braunstein, Pierre,Bedford, Robin B.
, p. 622 - 626 (2005)
Versatile methodologies for the synthesis of N-alkyl and N-aryl, and alkoxysilyl-functionalised mono- and bis-imidazolium salts are discussed. Such salts could find applications for heterogeneous N-heterocyclic catalysts and sol-gel materials.
Catalytic C-C coupling of furanic platform chemicals to high carbon fuel precursors over supported ionic liquids
Gebresillase, Mahlet N.,Seo, Jeong Gil
, (2021/11/11)
Imidazolium-based ionic liquid (IL) catalysts with different anions (Cl-, HSO4-, and CF3SO3-) were covalently anchored to the surface of fibrous silica (FS) by using alkyl chains as a linker. The prepared catalysts were applied for the C-C coupling reactions of 2-methylfuran (2-MF) with levulinic acid (LA), angelica lactone (AL), and ethyl levulinate (EL) to synthesize high carbon fuel precursors. The hydrophilic nature of FS supported IL catalyst having bisulfate anion was suitable for the self C-C coupling reaction of 2-MF and the reaction of 2-MF with LA. FS supported IL catalyst having triflate anion (FS-ILCF3SO3) exhibited high conversion and selectivity for the target fuel precursors from the C-C coupling reaction of 2-MF with AL and EL. The increased solubility, tunable acidity, and hydrophilicity/hydrophobicity of FS-ILHSO4 and FS-ILCF3SO3 promise a sustainable catalyst system. Supported ILs make the transformation processes greener and more efficient for large-scale production of biomass-derived fuel precursors.
Aerobic oxidation of alcohols catalyzed by in situ generated gold nanoparticles inside the channels of periodic mesoporous organosilica with ionic liquid framework
Bigdeli, Akram,Karimi, Babak,Khodadadi Karimvand, Somaiyeh,Khorasani, Mojtaba,Safari, Ali Asghar,Vali, Hojatollah
supporting information, p. 70 - 79 (2020/06/08)
In situ generated gold nanoparticles inside the nanospaces of periodic mesoporous organosilica with an imidazolium framework (Au?PMO-IL) were found to be highly active, selective, and reusable catalysts for the aerobic oxidation of activated and nonactivated alcohols under mild reaction conditions. The catalyst was characterized by nitrogen adsorption-desorption measurement, thermogravimetric analysis (TGA), transmission electron microscopy (TEM), elemental analysis (EA), diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma atomic emission spectroscopy (ICP-AES). The catalyst exhibited excellent catalytic activity in the presence of either Cs2CO3 (35 °C) or K2CO3 (60 °C) as reaction bases in toluene as a reaction solvent. Under both reaction conditions, various types of alcohols (up to 35 examples) including activated benzylic, primary and secondary aliphatic, heterocyclic, and challenging cyclic aliphatic alcohols converted to the expected carbonyl compounds in good to excellent yields and selectivity. The catalyst was also recovered and reused for at least seven reaction cycles. Data from three independent leaching tests indicated that amounts of leached gold particles were negligible (0.2 ppm). It is believed that the combination of bridged imidazolium groups and confined nanospaces of PMO-IL might be a major reason explaining the remarkable stabilization and homogeneous distribution of in situ generated gold nanoparticles, thus resulting in the highly active and recyclable catalyst system.
Design and synthesis of magnetic Fe3O4?NFC-ImSalophCu nanocatalyst based on cellulose nanofibers as a new and highly efficient, reusable, stable and green catalyst for the synthesis of 1,2,3-triazoles
Bagherzade, Ghodsieh,Eshghi, Hossein,Ghamari kargar, Pouya
, p. 32927 - 32937 (2020/09/21)
The Fe3O4?NFC-ImSalophCu catalyst was used as a highly stable, reusable, active, green catalyst for the synthesis of 1,2,3-triazolesviaone-pot three-component reaction of phenacyl bromides, sodium azide and alkynes. A Cu(ii)-Schiff base complex containing an imidazolium ionic phase was prepared and decorated on core shell Fe3O4?NFC magnetic nanoparticles (Fe3O4?NFC-ImSalophCu) and was used as an efficient catalyst. The heterogeneous catalyst was characterized by FT-IR spectroscopy, FE-SEM, TEM, XRD spectroscopy, EDX spectroscopy, VSM, and ICP spectroscopy. This catalyst shows the dual function of the metal sites and imidazolium moieties. The catalytic system mentioned above also showed excellent activity in the synthesis of bis 1,4-disubstituted 1,2,3-triazoles. Moreover, the catalyst could be recycled and reused for four cycles without any decrease in its catalytic activity.
Tungstate ion (WO42-) confined in hydrophilic/hydrophobic nanomaterials functionalized br?nsted acidic ionic liquid as highly active catalyst in the selective aerobic oxidation of alcohols in water
Luque, Rafael,Nafe, Mostafa,Rajabi, Fatemeh,Rezanejad Bardajee, Ghasem
, (2020/10/18)
A Br?nsted acidic Ionic Liquid containing tungstate anion functionalized polysiloxane network (PMO-IL-WO42-) was synthesized by simple self-condensation of tungstic acid and zwitterionic organosilane precursor possessing both imidazolium and sulfonate groups. Characterization by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), thermal gravimetric analysis TGA, nitrogen porosimetry, solid-state NMR spectroscopy and elemental analysis confirmed that both imidazolium cation and tungstate anion of zwitterion are successfully incorporated inside the organosilica framework. The catalytic activity of resulting hybrid PMO-IL- WO42- material was studied in the selective aerobic oxidation of primary and secondary alcohols using an atmospheric pressure of air in pure water. Due to the ionic liquid-based charged surface containing hydrophilic sulfonic acid and tungstate group, the synergistic hydrophilic/hydrophobic and redox effect of PMO-IL-WO42- as water-friendly catalyst facilitates and enhances the activity and selectivity toward the target oxidative products in water and proved to have a particularly broad substrate scope for reliable aerobic oxidation reaction. Furthermore, the catalyst showed outstanding stability and could be easily separated and reused at least ten reactions run under the same conditions as fresh catalyst without any loss of catalytic activity and product selectivity.
Synthetic process of silicon-based imidazole epoxy resin curing agent
-
Paragraph 0019; 0030; 0031; 0032, (2017/07/21)
The invention discloses a synthetic process of a silicon-based imidazole epoxy resin curing agent and belongs to the technical field of synthesis of curing agents. The synthetic process comprises the following steps: taking chloropropyl trichlorosilane and alcohol as raw materials, synthesizing chloropropyl siloxane by adopting a continuous method and then conducting reaction with an imidazole substance to obtain the silicon-based imidazole epoxy resin curing agent. The synthetic process of the silicon-based imidazole epoxy resin curing agent, disclosed by the invention, has the benefits that some raw materials used in the production process are simple and easy to obtain; in the whole production process, conditions are milder, the operation is simple, the equipment requirements are low, and high temperature, high pressure and other special processes are not required, so that the safety and the economy are good; wastewater containing COD is not generated, and byproducts are less; in the first step of esterification, no waste is generated, by-product hydrochloric acid is also a product with economic benefits, and the influence on the environment is less; chloropropyl silane is continuously produced, so that the reaction is favorably promoted, and the by-products are reduced.
Temperature-dependent immobilization of a tungsten peroxo complex that catalyzes the hydroxymethoxylation of olefins
Chen, Jizhong,Hua, Li,Chen, Chen,Guo, Li,Zhang, Ran,Chen, Angjun,Xiu, Yuhe,Liu, Xuerui,Hou, Zhenshan
, p. 1029 - 1037 (2015/06/08)
Abstract A tungsten peroxo complex stabilized by the bidentate picolinato ligand has been synthesized and then immobilized successfully on imidazole-functionalized silica. The immobilized tungsten-based catalyst was employed as an efficient catalyst for the one-pot synthesis of β-alkoxy alcohols from olefins and methanol with H2O2. Regarding the catalyst evaluation and the results of characterization by the various methods, it was demonstrated that the immobilization of tungsten peroxo complex was highly temperature-dependent. The tungsten peroxo complex can dissociate and diffuse into the liquid phase at reaction temperature, resulting in a homogeneous reaction. Nevertheless, the catalytically active species was anchored on the imidazole-functionalized silica by hydrogen bonding as the temperature was lowered to 0°C after the reaction, which thus offered a highly effective approach for recycling the catalyst for consecutive cycles. In addition, various olefins can be converted to the corresponding β-alkoxy alcohols with good conversion and selectivity under relative mild conditions by H2O2. Running hot and cold: A tungsten peroxo complex (see picture) can dissociate and diffuse into the liquid phase at the reaction temperature, resulting in a homogeneous reaction. After reaction, the catalytically active species was anchored on the functionalized silica by hydrogen-bonding as the temperature was lowered to 0°C. This offers an effective approach for catalyst recovery and recycling.
Tailoring photoluminescence properties in ionic nanoparticle networks
Kronstein, Martin,Akbarzadeh, Johanna,Drechsel, Christina,Peterlik, Herwig,Neouze, Marie-Alexandra
, p. 10763 - 10774 (2014/12/10)
To investigate the original and promising luminescence properties of ionic nanoparticle networks (INN), various material compositions were investigated. In this work, the linker used to network the silica nanoparticles was varied; numerous substituted or non-substituted imidazolium, pyrazolium and pyridinium linkers are presented. Photoluminescence experiments on the INN hybrid materials revealed strong emission bands over a broad range in the visible region of the light spectrum. Varying the aromatic linker between the imidazolium units induced clear shifts of the emission maxima up to 100 nm, as a consequence of π-π stacking interactions. Steric hindrance and inductive effects of the substituents, introduced on the aromatic units, also strongly influenced the luminescence properties of the materials by modifying the π-π stacking between the imidazolium rings. Small and wide-angle X-ray scattering (SAXS, WAXS) experiments revealed a clear trend between the obtained structural parameters (short-range order parameter and distance of the aromatic units within the hybrid material) and the luminescence quantum yields of the INN materials. Inducing luminescence: Interesting luminescence properties were observed in ionic nanoparticle networks containing no luminophore. "Playing" with the nanoparticle linker allowed tailoring of the excitation and emission wavelength over a broad range. A clear trend between the obtained structural parameters (obtained from small-angle X-ray scattering experiments) and the luminescence quantum yields of the ionic nanoparticle network materials could be evidenced (see figure).
Dual acidic ionic liquid immobilized on α-Fe2O3-MCM-41 magnetic mesoporous materials as the hybrid acidic nanocatalyst for the synthesis of pyrimido[4,5-d]pyrimidine derivatives
Rostamizadeh, Shahnaz,Nojavan, Masoomeh,Aryan, Reza,Azad, Mohammad
, p. 1772 - 1783 (2015/02/19)
Magnetic α-Fe2O3-MCM-41 mesoporous material functionalized by dual acidic ionic liquid (DAIL) was prepared through a two-step approach as a novel powerful acidic catalyst which provides high ionic media for reactions, by means of post-surface grafting of the mesochannels of α-Fe2O3-MCM-41 materials with 3-sul-fobutyl- 1-(3-propyltrimethoxysilane)imidazolium hydrogen sulfate as DAIL. Mesoporous MCM-41 was simply packed on the surface of ferric oxide nanoparticles and DAIL was efficiently incorporated into the mesochannels of MCM-41 generating Lewis and Br?nsted acidic sites. The catalyst was characterized by FT-IR, X-ray powder diffraction, HRTEM, vibrating sample magnetometer, X-ray energy diffraction spectra, thermogravimetric and differential thermal analyses, and N2 adsorption-desorption measurements. The synthesized hybrid acidic MCM-41 showed good catalytic performance in the one-pot synthesis of pyrimido[4,5-d]pyrimidine derivatives using 6-aminouracil, aldehyde, and urea or thiourea under solvent free conditions. Moreover, it was proved that under this condition, the use of such a hybrid material as a catalyst plays the role of rendering the reactions while neither the α-Fe2O3-MCM-41 nor the 3-methyl-1-(4-sulfonic acid)butylimidazolium hydrogen sulfate were able to promote this reaction.
