The Experts below are selected from a list of 22755 Experts worldwide ranked by ideXlab platform
Asim Bhaumik - One of the best experts on this subject based on the ideXlab platform.
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solvent free environmentally benign approach for the selective olefin epoxidation catalyzed by mn iii immobilized Mesoporous nanoarchitectonics
Journal of Nanoscience and Nanotechnology, 2020Co-Authors: Luna Paul, Asim Bhaumik, Biplab Banerjee, Mahammad AliAbstract:Immobilization of transition metal complexes at the surface of 2D-hexagonal functionalized SBA-15 Material is one of the promising strategies in designing an efficient catalytic system for the olefin epoxidation reaction. Here we have immobilized Mn(III) on the Schiff-base anchore 2D-hexagonally ordered functionalised Mesoporous SBA-15 Material. Powder X-ray diffraction (PXRD), N₂-sorption and high resolution transmission electron microscopic (HRTEM) studies of the resulting SBA-15-SB-Mn Material suggested 2D-hexagonally ordered porous nanostructure and X-ray photoelectron spectroscopy (XPS) analysis suggested the presence of surface bound Mn(III) species in this nanoMaterial. This Mesoporous Material showed excellent performance in the selective catalytic oxidation of various alkenes to the corresponding epoxides in the presence of tert-butyl hydroperoxide (TBHP, 70% aqueous solution) as oxidant under solvent-free mild reaction conditions together with high recycling efficiency.
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one pot thioetherification of aryl halides with thiourea and benzyl bromide in water catalyzed by cu grafted furfural imine functionalized Mesoporous sba 15
Chemical Communications, 2012Co-Authors: John Mondal, Arindam Modak, Arghya Dutta, S Basu, D Bhattacharyya, Asim BhaumikAbstract:Surface functionalization of SBA-15 followed by its reaction with Cu(OAc)2 has been carried out to develop a new Cu-grafted functionalized Mesoporous Material, which catalyzes one-pot three component coupling of different aryl halides with thiourea and benzyl bromide in aqueous medium to produce aryl thioethers in very good yields (80–88%).
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new Mesoporous magnesium aluminum mixed oxide and its catalytic activity in liquid phase baeyer villiger oxidation reaction
Chemical Engineering Science, 2012Co-Authors: Manidipa Paul, John Mondal, Manickam Sasidharan, Asim BhaumikAbstract:Abstract Baeyer–Villiger oxidation is a very important reaction in the organic synthesis for designing value added lactone/esters from the respective carbonyl compounds. Usually an active metal-containing Material in the presence of peroxides catalyzes this reaction. Here Mesoporous magnesium–aluminum mixed oxide Material has been synthesized hydrothermally using lauric acid as structure-directing or capping agent. This Mesoporous Material is thoroughly characterized by powder XRD, N 2 and CO 2 adsorption, HR TEM, FE SEM-EDS, FT IR and TG-DTA techniques. The Material showed moderately good surface area (244 m 2 g −1 ) and mesoporosity with nanoscale pore dimension (ca. 4.8 nm). Liquid phase Baeyer–Villiger oxidations of cyclic and acyclic ketones have been carried out using this Mesoporous Material as catalyst in the presence of hydrogen peroxide as oxidant and benzonitrile as promoter.
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Facile C-S coupling reaction of aryl iodide and thiophenol catalyzed by Cu-grafted furfural functionalized Mesoporous organosilica.
Dalton transactions (Cambridge England : 2003), 2011Co-Authors: John Mondal, Arindam Modak, Arghya Dutta, Asim BhaumikAbstract:A new functionalized Mesoporous organosilica has been designed via Schiff-base condensation of furfural and 3-aminopropyltriethoxy-silane (APTES) followed by its hydrothermal co-condensation with tetraethylorthosilicate (TEOS) in the presence of a cationic surfactant CTAB. Subsequent reaction of this Mesoporous organosilica with Cu(OAc)2 in absolute ethanol leads to the formation of a new Cu(II)-grafted Mesoporous organosilica catalyst 1. Powder XRD, HR TEM, FE SEM, N2 sorption and FT IR spectroscopic tools are used to characterize the Materials. This Cu-anchored Mesoporous Material acts as an efficient, reusable catalyst in the aryl-sulfur coupling reaction between aryl iodide and thiophenol for the synthesis of value added diarylsulfides.
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soft templating approach for the synthesis of high surface area and superparamagnetic Mesoporous iron oxide Materials
Microporous and Mesoporous Materials, 2010Co-Authors: C Vazquezvazquez, Atanu Mitra, Arturo M Lopezquintela, Bidyut K Paul, Asim BhaumikAbstract:Abstract Designing pores of nanoscale dimension into a magnetic Material can engineer the surface nanostructure, resulting in a Mesoporous Material with unique physicochemical properties. Here we report a simple soft-templating approach for the synthesis of new Mesoporous iron oxide Materials having semi-crystalline pore wall by using an anionic surfactant sodiumdodecylsulfate as the structure-directing agent (SDA) or template at low temperature. On removal of the SDA molecules through solvent extraction the mesostructure is preserved and the Material shows considerably high BET surface area and type IV isotherms corresponding to the mesopores. This Mesoporous Fe2O3 Material showed superparamagnetic behavior and hence this template-assisted synthesis of Mesoporous Fe2O3 can find its potential utility in designing magnetic nanostructured Materials.
Liming Yuan - One of the best experts on this subject based on the ideXlab platform.
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a highly ordered chiral inorganic Mesoporous Material used as stationary phase for high resolution gas chromatographic separations
Journal of Chromatography A, 2018Co-Authors: Junhui Zhang, Shengming Xie, Liming YuanAbstract:Abstract A highly ordered chiral Mesoporous silica-coated capillary column has been used for high-resolution gas chromatographic separations. The column has excellent selectivity, not only for the separation of isomers, polycyclic aromatic hydrocarbons, linear alkanes, long chain alkanes, Grob’s test mixture and aromatic hydrocarbons, but also for the resolution of different classes of chiral compounds. Additionally, the column exhibits high column efficiency, excellent temperature resistance, and analysis times are short. This is the first report of a highly ordered chiral inorganic Mesoporous silica used in separation science.
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novel inorganic Mesoporous Material with chiral nematic structure derived from nanocrystalline cellulose for high resolution gas chromatographic separations
Analytical Chemistry, 2014Co-Authors: Junhui Zhang, Shengming Xie, Mei Zhang, Liming YuanAbstract:Chiral nematic Mesoporous silica (CNMS) has attracted widespread attention due to some unique features, such as its nematic structure, chirality, large pore size, high temperature resistance, low cost, and ease of preparation. We first reported the use of CNMS as a stationary phase for capillary gas chromatography (GC). The CNMS-coated capillary column not only gives good selectivity for the separation of linear alkanes, aromatic hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), and isomers but also offers excellent enantioselectivity for chiral compounds. Compared with enantioseparations on commercial β-DEX 120 and Chirasil-l-Val columns, a CNMS-coated capillary column offers excellent enantioselectivity, chiral recognition complementarity, and the separation of analytes within short elution times. It can also be potentially applied in high-temperature GC at more than 350 °C. This work indicates that CNMS could soon become very attractive for separations.
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Novel Inorganic Mesoporous Material with Chiral Nematic Structure Derived from Nanocrystalline Cellulose for High-Resolution Gas Chromatographic Separations
2014Co-Authors: Junhui Zhang, Shengming Xie, Mei Zhang, Liming YuanAbstract:Chiral nematic Mesoporous silica (CNMS) has attracted widespread attention due to some unique features, such as its nematic structure, chirality, large pore size, high temperature resistance, low cost, and ease of preparation. We first reported the use of CNMS as a stationary phase for capillary gas chromatography (GC). The CNMS-coated capillary column not only gives good selectivity for the separation of linear alkanes, aromatic hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), and isomers but also offers excellent enantioselectivity for chiral compounds. Compared with enantioseparations on commercial β-DEX 120 and Chirasil-l-Val columns, a CNMS-coated capillary column offers excellent enantioselectivity, chiral recognition complementarity, and the separation of analytes within short elution times. It can also be potentially applied in high-temperature GC at more than 350 °C. This work indicates that CNMS could soon become very attractive for separations
Anand Ramanathan - One of the best experts on this subject based on the ideXlab platform.
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sntud 1 a solid acid catalyst for three component coupling reactions at room temperature
Green Chemistry, 2013Co-Authors: Muthusamy Poomalai Pachamuthu, K Shanthi, Rafael Luque, Anand RamanathanAbstract:A novel wormhole structured Mesoporous Material containing tin, SnTUD-1, was prepared by a direct hydrothermal synthesis method using triethanolamine (TEA) as an organic inexpensive Mesoporous structure directing agent. XRD and N2 sorption studies of SnTUD-1 confirmed the amorphous Mesoporous nature of SnTUD-1, which possessed a large surface area of 555 m2 g−1 and a pore diameter of 7.4 nm. HR-TEM further ascertained the disordered pores in their morphology and the presence of nano-domains of SnO2 species. The nature of the Sn4+ ion co-ordination with the silica matrix was evaluated by using different techniques including diffuse reflectance UV-Vis, FTIR, 29Si MAS NMR and XPS. SnTUD-1 had an interesting Lewis acidity as measured by FTIR of pyridine adsorption which provided excellent activities in one-pot three-component Mannich-type reactions of ketones with aldehydes and amines at room temperature.
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sntud 1 a solid acid catalyst for three component coupling reactions at room temperature
Green Chemistry, 2013Co-Authors: Muthusamy Poomalai Pachamuthu, K Shanthi, Rafael Luque, Anand RamanathanAbstract:A novel wormhole structured Mesoporous Material containing tin, SnTUD-1, was prepared by a direct hydrothermal synthesis method using triethanolamine (TEA) as an organic inexpensive Mesoporous structure directing agent. XRD and N2 sorption studies of SnTUD-1 confirmed the amorphous Mesoporous nature of SnTUD-1, which possessed a large surface area of 555 m2 g−1 and a pore diameter of 7.4 nm. HR-TEM further ascertained the disordered pores in their morphology and the presence of nano-domains of SnO2 species. The nature of the Sn4+ ion co-ordination with the silica matrix was evaluated by using different techniques including diffuse reflectance UV-Vis, FTIR, 29Si MAS NMR and XPS. SnTUD-1 had an interesting Lewis acidity as measured by FTIR of pyridine adsorption which provided excellent activities in one-pot three-component Mannich-type reactions of ketones with aldehydes and amines at room temperature.
Junhui Zhang - One of the best experts on this subject based on the ideXlab platform.
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a highly ordered chiral inorganic Mesoporous Material used as stationary phase for high resolution gas chromatographic separations
Journal of Chromatography A, 2018Co-Authors: Junhui Zhang, Shengming Xie, Liming YuanAbstract:Abstract A highly ordered chiral Mesoporous silica-coated capillary column has been used for high-resolution gas chromatographic separations. The column has excellent selectivity, not only for the separation of isomers, polycyclic aromatic hydrocarbons, linear alkanes, long chain alkanes, Grob’s test mixture and aromatic hydrocarbons, but also for the resolution of different classes of chiral compounds. Additionally, the column exhibits high column efficiency, excellent temperature resistance, and analysis times are short. This is the first report of a highly ordered chiral inorganic Mesoporous silica used in separation science.
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novel inorganic Mesoporous Material with chiral nematic structure derived from nanocrystalline cellulose for high resolution gas chromatographic separations
Analytical Chemistry, 2014Co-Authors: Junhui Zhang, Shengming Xie, Mei Zhang, Liming YuanAbstract:Chiral nematic Mesoporous silica (CNMS) has attracted widespread attention due to some unique features, such as its nematic structure, chirality, large pore size, high temperature resistance, low cost, and ease of preparation. We first reported the use of CNMS as a stationary phase for capillary gas chromatography (GC). The CNMS-coated capillary column not only gives good selectivity for the separation of linear alkanes, aromatic hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), and isomers but also offers excellent enantioselectivity for chiral compounds. Compared with enantioseparations on commercial β-DEX 120 and Chirasil-l-Val columns, a CNMS-coated capillary column offers excellent enantioselectivity, chiral recognition complementarity, and the separation of analytes within short elution times. It can also be potentially applied in high-temperature GC at more than 350 °C. This work indicates that CNMS could soon become very attractive for separations.
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Novel Inorganic Mesoporous Material with Chiral Nematic Structure Derived from Nanocrystalline Cellulose for High-Resolution Gas Chromatographic Separations
2014Co-Authors: Junhui Zhang, Shengming Xie, Mei Zhang, Liming YuanAbstract:Chiral nematic Mesoporous silica (CNMS) has attracted widespread attention due to some unique features, such as its nematic structure, chirality, large pore size, high temperature resistance, low cost, and ease of preparation. We first reported the use of CNMS as a stationary phase for capillary gas chromatography (GC). The CNMS-coated capillary column not only gives good selectivity for the separation of linear alkanes, aromatic hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), and isomers but also offers excellent enantioselectivity for chiral compounds. Compared with enantioseparations on commercial β-DEX 120 and Chirasil-l-Val columns, a CNMS-coated capillary column offers excellent enantioselectivity, chiral recognition complementarity, and the separation of analytes within short elution times. It can also be potentially applied in high-temperature GC at more than 350 °C. This work indicates that CNMS could soon become very attractive for separations
Vinod Kumar Gupta - One of the best experts on this subject based on the ideXlab platform.
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synthesis characterization and adsorptive application of ferrocene based Mesoporous Material for hazardous dye congo red
Journal of Industrial and Engineering Chemistry, 2015Co-Authors: Sumanjit Kaur, Seema Rani, Vipin Kumar, Rakesh Kumar Mahajan, Mohammad Asif, Inderjeet Tyagi, Vinod Kumar GuptaAbstract:Abstract Mesoporous adsorbent is prepared first time using ferrocene based surfactant as a template and adsorption of azo dye Congo red is investigated. Adsorbent is characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, dynamic light scattering and N2 adsorption–desorption and deduced a lofty surface area of 342 m2/g. Effect of contact time, adsorbent dose, initial dye concentration and temperature were speculated to optimize adsorption conditions. Experimental data were contemplated for various kinetics and thermodynamic models at different temperatures and insinuated that adsorption process is film diffusion controlled and followed second order kinetics. Langmuir model imparted high value of monolayer capacity as 312.5 mg/g. The values of thermodynamic parameters like enthalpy (ΔH) and entropy (ΔS) were found to be 49.94 kJ/mol and 265.5 J/K/mol, respectively, and negative values of ΔG corroborated that the present adsorption system is feasible, spontaneous and endothermic.
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synthesis and adsorption properties of Mesoporous Material for the removal of dye safranin kinetics equilibrium and thermodynamics
Journal of Industrial and Engineering Chemistry, 2015Co-Authors: Sumanjit Kaur, Seema Rani, Rakesh Kumar Mahajan, Mohammad Asif, Vinod Kumar GuptaAbstract:Abstract A highly ordered large pore Mesoporous adsorbent MCM-41 is synthesized and characterized by XRD, BET, FTIR and SEM. Effect of contact time, initial dye concentration, adsorbent dose, pH and temperature were studied for adsorption of dye safranin on MCM-41. Experimental data were investigated for various thermodynamic models and kinetic models and corroborated that adsorption followed second order kinetic model. Langmuir model evidenced the maximum adsorption capacity as 68.8 mg g −1 at 303 K. Thermodynamic parameters surmised that adsorption of safranin on MCM-41 is spontaneous, exothermic and feasible.
