The Experts below are selected from a list of 13872 Experts worldwide ranked by ideXlab platform
T. P. Radhakrishnan - One of the best experts on this subject based on the ideXlab platform.
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Palladium Nanoparticle-Embedded Polymer Thin Film “Dip Catalyst” for Suzuki–Miyaura Reaction
ACS Catalysis, 2012Co-Authors: E. Hariprasad, T. P. RadhakrishnanAbstract:Hallmarks of a successful catalyst include simplicity of design and low cost of fabrication, high efficiency, facile recovery and extensive reusability, amenability to monitoring between reuses, and ease of scale up. Even though the number of Palladium Nanoparticle based catalysts reported for the Suzuki–Miyaura reaction has grown exponentially in recent years, the aforesaid criteria are rarely met in a single system. We present a Palladium Nanoparticle-embedded polymer thin film which functions as a highly efficient and reusable “dip catalyst” for the Suzuki–Miyaura reaction. The multilayer free-standing nanocomposite thin film is fabricated using a simple in situ process through thermal annealing of a spin-coated film of poly(vinyl alcohol) (PVA) containing the Palladium precursor. Fabrication parameters of the Pd-PVA film are optimized for enhanced catalyst efficiency. The catalyst is shown to produce very high yield, turn over number and turn over frequency in the prototypical reaction of iodobenzene ...
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Palladium Nanoparticle embedded polymer thin film dip catalyst for suzuki miyaura reaction
ACS Catalysis, 2012Co-Authors: E. Hariprasad, T. P. RadhakrishnanAbstract:Hallmarks of a successful catalyst include simplicity of design and low cost of fabrication, high efficiency, facile recovery and extensive reusability, amenability to monitoring between reuses, and ease of scale up. Even though the number of Palladium Nanoparticle based catalysts reported for the Suzuki–Miyaura reaction has grown exponentially in recent years, the aforesaid criteria are rarely met in a single system. We present a Palladium Nanoparticle-embedded polymer thin film which functions as a highly efficient and reusable “dip catalyst” for the Suzuki–Miyaura reaction. The multilayer free-standing nanocomposite thin film is fabricated using a simple in situ process through thermal annealing of a spin-coated film of poly(vinyl alcohol) (PVA) containing the Palladium precursor. Fabrication parameters of the Pd-PVA film are optimized for enhanced catalyst efficiency. The catalyst is shown to produce very high yield, turn over number and turn over frequency in the prototypical reaction of iodobenzene ...
K R Gopidas - One of the best experts on this subject based on the ideXlab platform.
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synthesis characterization and catalytic applications of Palladium Nanoparticle cored dendrimers stabilized by metal carbon bonds
European Journal of Organic Chemistry, 2012Co-Authors: V Ratheesh K Kumar, Sreedevi Krishnakumar, K R GopidasAbstract:The synthesis and characterization of four generations of Palladium Nanoparticle-cored Frechet-type dendrimers (Pd-Gn) possessing direct Palladium–carbon bonds are reported. These core–shell materials have been synthesized by the simultaneous reduction of different generation diazodendrons and PdII in an organic medium. The resulting organic–inorganic hybrid materials were characterized by IR, NMR and UV/Vis spectroscopic techniques. The formation of nearly spherical particles of 2–4 nm diameter was confirmed by TEM studies. The efficiency of one member of this series, Pd-G1, in catalysing important C–C bond-forming reactions such as Suzuki, Stille and Hiyama coupling reactions was investigated. The results clearly show that Pd-G1 can efficiently catalyse the cross-coupling of arylboronic acids, aryl stannanes and organosilicon compounds with differently substituted aryl halides in addition to efficiently catalysing hydrogenation reactions. The catalyst exhibited good recovery and recyclability in Suzuki coupling reactions. The study suggests that a single catalyst capable of catalysing several reactions can be designed.
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Palladium Nanoparticle cored g1 dendrimer stabilized by carbon pd bonds synthesis characterization and use as chemoselective room temperature hydrogenation catalyst
Tetrahedron Letters, 2011Co-Authors: Venugopal Ratheesh K Kumar, K R GopidasAbstract:Abstract Palladium Nanoparticle-cored Frechet type G 1 -dendrimer ( Pd-G 1 ) stabilized by Pd–carbon bonds is synthesized and characterized by IR, NMR, UV–Vis and TEM. Pd-G 1 was found to be a highly efficient, chemoselective and reusable catalyst for the room temperature hydrogenation of carbon–carbon multiple bonds. Reducible functionalities like CHO, CO, COOR, CN, NO 2 and halogens were unaffected. Pd-G 1 is projected as an efficient catalyst for the selective hydrogenation of carbon-carbon multiple bonds in multifunctional organic molecules.
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synthesis characterization and catalytic applications of a Palladium Nanoparticle cored dendrimer
Nano Letters, 2003Co-Authors: K R Gopidas, James K Whitesell, Marye Anne FoxAbstract:A Palladium-Nanoparticle-cored G-3 dendrimer, characterized by TEM, TGA, absorption, and IR spectroscopies, has approximately 300 Pd atoms in the metallic core and an average diameter of 2.0 nm, to which are attached fourteen G-3 dendrons. Nearly 90% of the metal Nanoparticle surface is unpassivated and available for catalysis. The dendrons inhibit metal agglomeration without adversely affecting chemical reactivity. Thus, preliminary investigations have shown that Pd-G-3 can efficiently catalyze Heck and Suzuki reactions.
E. Hariprasad - One of the best experts on this subject based on the ideXlab platform.
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Palladium Nanoparticle-Embedded Polymer Thin Film “Dip Catalyst” for Suzuki–Miyaura Reaction
ACS Catalysis, 2012Co-Authors: E. Hariprasad, T. P. RadhakrishnanAbstract:Hallmarks of a successful catalyst include simplicity of design and low cost of fabrication, high efficiency, facile recovery and extensive reusability, amenability to monitoring between reuses, and ease of scale up. Even though the number of Palladium Nanoparticle based catalysts reported for the Suzuki–Miyaura reaction has grown exponentially in recent years, the aforesaid criteria are rarely met in a single system. We present a Palladium Nanoparticle-embedded polymer thin film which functions as a highly efficient and reusable “dip catalyst” for the Suzuki–Miyaura reaction. The multilayer free-standing nanocomposite thin film is fabricated using a simple in situ process through thermal annealing of a spin-coated film of poly(vinyl alcohol) (PVA) containing the Palladium precursor. Fabrication parameters of the Pd-PVA film are optimized for enhanced catalyst efficiency. The catalyst is shown to produce very high yield, turn over number and turn over frequency in the prototypical reaction of iodobenzene ...
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Palladium Nanoparticle embedded polymer thin film dip catalyst for suzuki miyaura reaction
ACS Catalysis, 2012Co-Authors: E. Hariprasad, T. P. RadhakrishnanAbstract:Hallmarks of a successful catalyst include simplicity of design and low cost of fabrication, high efficiency, facile recovery and extensive reusability, amenability to monitoring between reuses, and ease of scale up. Even though the number of Palladium Nanoparticle based catalysts reported for the Suzuki–Miyaura reaction has grown exponentially in recent years, the aforesaid criteria are rarely met in a single system. We present a Palladium Nanoparticle-embedded polymer thin film which functions as a highly efficient and reusable “dip catalyst” for the Suzuki–Miyaura reaction. The multilayer free-standing nanocomposite thin film is fabricated using a simple in situ process through thermal annealing of a spin-coated film of poly(vinyl alcohol) (PVA) containing the Palladium precursor. Fabrication parameters of the Pd-PVA film are optimized for enhanced catalyst efficiency. The catalyst is shown to produce very high yield, turn over number and turn over frequency in the prototypical reaction of iodobenzene ...
Xiaoming Zheng - One of the best experts on this subject based on the ideXlab platform.
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Palladium catalyzed transformation of renewable oils into diesel components
Advanced Synthesis & Catalysis, 2010Co-Authors: Jinzhao Duan, Yuqi Ding, Xiaoming ZhengAbstract:A size-controlled Palladium Nanoparticle catalyst prepared by adsorption of colloidal Palladium Nanoparticles on barium sulfate is efficient and highly selective in transforming vegetable oils into diesel-like fuel. Preliminary kinetic investigations using model compounds indicated that decarboxylation of aliphatic esters on Palladium in a hydrogen-rich atmosphere showed a zero-order rate. Hydrogen temperature-programmed desorption measurements revealed that the high-temperature desorption of hydrogen species might be the rate-determining step.
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Palladium‐Catalyzed Transformation of Renewable Oils into Diesel Components
Advanced Synthesis & Catalysis, 2010Co-Authors: Junxing Han, Yuqi Ding, Jinzhao Duan, Hui Sun, Hui Lou, Xiaoming ZhengAbstract:A size-controlled Palladium Nanoparticle catalyst prepared by adsorption of colloidal Palladium Nanoparticles on barium sulfate is efficient and highly selective in transforming vegetable oils into diesel-like fuel. Preliminary kinetic investigations using model compounds indicated that decarboxylation of aliphatic esters on Palladium in a hydrogen-rich atmosphere showed a zero-order rate. Hydrogen temperature-programmed desorption measurements revealed that the high-temperature desorption of hydrogen species might be the rate-determining step.
Bhalchandra M. Bhanage - One of the best experts on this subject based on the ideXlab platform.
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transfer hydrogenation of nitroarenes into anilines by Palladium Nanoparticles via dehydrogenation of dimethylamine borane complex
RSC Advances, 2015Co-Authors: Nilesh M Patil, Manohar A Bhosale, Bhalchandra M. BhanageAbstract:This work reports a simple and highly efficient protocol for reduction of nitroarenes to corresponding amines via dehydrogenation of dimethylamine borane using Palladium Nanoparticle (Pd NPs) as a versatile heterogeneous catalyst. The facile approach for the synthesis of Pd NPs within 15 min in aqueous medium has been reported. The Pd NPs were well characterized using various analytical techniques such as XRD, FEG-SEM, TEM, EDAX and XPS. The developed catalytic system uses environmentally benign dimethylamine borane as a reducing agent which is highly stable, water soluble and nontoxic. The various amines were synthesized from nitroarenes in excellent yields within 10–60 min at room temperature. The catalyst was reused up to four successive cycles without significant loss in its catalytic activity.
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Solar energy assisted Palladium Nanoparticles synthesis in aqueous medium
Materials Letters, 2012Co-Authors: Aniruddha B. Patil, Satish R. Lanke, Krishna M. Deshmukh, Aniruddha B. Pandit, Bhalchandra M. BhanageAbstract:Abstract A new approach for the synthesis of Palladium Nanoparticles using the concept of concentrated solar energy has been developed. The use of citric acid as a greener reducing agent and polyvinyl pyrrolidone (PVP) as a capping agent with Palladium precursor assists the synthesis of multiple twinned particles in aqueous reaction medium. Solar energy was concentrated using Fresnel lens. The effect of irradiation time on crystal growth has been studied. This is the first report wherein concentrated solar energy concept was used for the Palladium Nanoparticle (PdNP) synthesis. Application of solar energy over conventional energy sources makes this protocol environmentally benign.