Browsing by Author "Bhat, P.B."
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Item An immobilised Co(ii) and Ni(ii) Schiff base magnetic nanocatalyst via a click reaction: A greener approach for alcohol oxidation(Royal Society of Chemistry, 2015) Bhat, P.B.; Badekai Ramachandra, B.R.A Schiff base immobilised nanocatalyst was synthesized via copper catalysed alkyne azide cycloaddition (CuAAC) on a magnetic support. The nanocatalyst exhibited high accessible active sites with a surface area of 76 m2 g-1 for a cobalt complex and 57 m2 g-1 for a nickel complex. A strong interaction between the magnetic support and the Schiff base was achieved by avoiding leaching during the course of reaction. The nanocatalyst efficiently oxidised both primary and secondary alcohols to carbonyl with improved yield in a solventless system rendering a greener approach. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2015.Item An immobilised Co(ii) and Ni(ii) Schiff base magnetic nanocatalyst via a click reaction: A greener approach for alcohol oxidation(2015) Bhat, P.B.; Bhat, B.R.A Schiff base immobilised nanocatalyst was synthesized via copper catalysed alkyne azide cycloaddition (CuAAC) on a magnetic support. The nanocatalyst exhibited high accessible active sites with a surface area of 76 m2 g-1 for a cobalt complex and 57 m2 g-1 for a nickel complex. A strong interaction between the magnetic support and the Schiff base was achieved by avoiding leaching during the course of reaction. The nanocatalyst efficiently oxidised both primary and secondary alcohols to carbonyl with improved yield in a solventless system rendering a greener approach. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2015.Item Immobilized magnetic nano catalyst for oxidation of alcohol(2015) Bhat, P.B.; Rajarao, R.; Sahajwalla, V.; Bhat, B.R.Covalent attachment of Schiff base on magnetic nanoparticles yielded good selectivity for oxidation of alcohols. The ferromagnetic interaction in the complex added comprehensive advantage in enhancing the catalytic activity of the nanocatalyst. A greener approach for alcohol oxidation was achieved in solventless method with good yield (>78%). Leaching experiments confirmed a strong interaction between magnetic support and complex. The catalyst showed significant conversion even after 5 catalytic runs. 2015 Elsevier B.V. All rights reserved.Item Immobilized magnetic nano catalyst for oxidation of alcohol(Elsevier, 2015) Bhat, P.B.; Rajarao, R.; Sahajwalla, V.; Badekai Ramachandra, B.R.Covalent attachment of Schiff base on magnetic nanoparticles yielded good selectivity for oxidation of alcohols. The ferromagnetic interaction in the complex added comprehensive advantage in enhancing the catalytic activity of the nanocatalyst. A greener approach for alcohol oxidation was achieved in solventless method with good yield (>78%). Leaching experiments confirmed a strong interaction between magnetic support and complex. The catalyst showed significant conversion even after 5 catalytic runs. © 2015 Elsevier B.V. All rights reserved.Item Magnetically recoverable immobilized cobalt nanocatalyst for oxidation of alcohols(2016) Bhat, P.B.; Bhat, B.R.A magnetically recoverable symmetric teradentate Schiff base cobalt complex immobilised silica-coated Fe3O4nanoparticles exhibited efficient oxidation of the alcohols to carbonyls with mild H2O2oxidant. Reverse coprecipitation method yielded superparamagnetic Fe3O4at room temperature. The nanocatalyst exhibited good recoverability without significant loss in activity and selectivity within successive runs. 2016 American Scientific Publishers. All rights reserved.Item Magnetically recoverable immobilized cobalt nanocatalyst for oxidation of alcohols(American Scientific Publishers, 2016) Bhat, P.B.; Badekai Ramachandra, B.R.A magnetically recoverable symmetric teradentate Schiff base cobalt complex immobilised silica-coated Fe3O4nanoparticles exhibited efficient oxidation of the alcohols to carbonyls with mild H2O2oxidant. Reverse coprecipitation method yielded superparamagnetic Fe3O4at room temperature. The nanocatalyst exhibited good recoverability without significant loss in activity and selectivity within successive runs. © 2016 American Scientific Publishers. All rights reserved.Item Magnetically retrievable nickel hydroxide functionalised AFe2O4 (A = Mn, Ni) spinel nanocatalyst for alcohol oxidation(2016) Bhat, P.B.; Bhat, B.R.Ultrasmall nickel hydroxide functionalised AFe2O4 (A = Mn, Ni) nanocatalyst was synthesized by traditional co-precipitation method and was examined for oxidation of aromatic alcohols to carbonyls using hydrogen peroxide as terminal oxidant. A very high surface area of 104.55 m2 g?1 was achieved for ferromagnetic MnFe2O4 and 100.50 m2 g?1 for superparamagnetic NiFe2O4, respectively. Efficient oxidation was observed due to the synergized effect of nickel hydroxide (bronsted base) on Lewis center (Fe) of the nanocatalyst. Catalyst recycling experiments revealed that the ultrasmall nanocatalyst can be easily recovered by external magnet and applied for nearly complete oxidation of alcohols for at least five successive cycles. Furthermore, the nickel hydroxide functionalised ultrasmall nanocatalyst exhibited higher efficiency for benzyl alcohol oxidation compared to Ni(OH)2, bare MnFe2O4 and NiFe2O4. Higher conversion rate was observed for nickel hydroxide functionalised NiFe2O4 compared to MnFe2O4. Ultrasmall magnetic nickel hydroxide functionalised nanocatalyst showed environmental friendly, greener route for the oxidation of alcohols without significant loss in activity and selectivity within successive runs. 2015, The Author(s).Item Magnetically retrievable nickel hydroxide functionalised AFe2O4 (A = Mn, Ni) spinel nanocatalyst for alcohol oxidation(Springer Nature, 2016) Bhat, P.B.; Badekai Ramachandra, B.R.Ultrasmall nickel hydroxide functionalised AFe2O4 (A = Mn, Ni) nanocatalyst was synthesized by traditional co-precipitation method and was examined for oxidation of aromatic alcohols to carbonyls using hydrogen peroxide as terminal oxidant. A very high surface area of 104.55 m2 g?1 was achieved for ferromagnetic MnFe2O4 and 100.50 m2 g?1 for superparamagnetic NiFe2O4, respectively. Efficient oxidation was observed due to the synergized effect of nickel hydroxide (bronsted base) on Lewis center (Fe) of the nanocatalyst. Catalyst recycling experiments revealed that the ultrasmall nanocatalyst can be easily recovered by external magnet and applied for nearly complete oxidation of alcohols for at least five successive cycles. Furthermore, the nickel hydroxide functionalised ultrasmall nanocatalyst exhibited higher efficiency for benzyl alcohol oxidation compared to Ni(OH)2, bare MnFe2O4 and NiFe2O4. Higher conversion rate was observed for nickel hydroxide functionalised NiFe2O4 compared to MnFe2O4. Ultrasmall magnetic nickel hydroxide functionalised nanocatalyst showed environmental friendly, greener route for the oxidation of alcohols without significant loss in activity and selectivity within successive runs. © 2015, The Author(s).Item Nano Fe3O4@APTES@Ni(OH)2 as a catalyst for alcohol oxidation(2015) Bhat, P.B.; Bhat, B.R.A nanorod shaped nickel hydroxide coated ferrite nanocatalyst was synthesized by a traditional co-precipitation method. The particle size of the nanoferrite was tuned using a variable surfactant ratio to achieve a high surface area. A very high BET surface area (334.55 m2 g-1) was achieved for particles with sizes of 40-130 nm. The superparamagnetic reusable catalyst was found to be active for the selective liquid phase oxidation of alcohols with hydrogen peroxide as a mild oxidant. Nickel hydroxide acted as a Bronsted base working in synergy with the nanoferrite catalyst for alcohol oxidation. The catalytic system was found to catalyse primary and secondary alcohols efficiently (86%) to their corresponding carbonyls in good yields. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2015.Item Nano Fe3O4@APTES@Ni(OH)2 as a catalyst for alcohol oxidation(Royal Society of Chemistry, 2015) Bhat, P.B.; Badekai Ramachandra, B.R.A nanorod shaped nickel hydroxide coated ferrite nanocatalyst was synthesized by a traditional co-precipitation method. The particle size of the nanoferrite was tuned using a variable surfactant ratio to achieve a high surface area. A very high BET surface area (334.55 m2 g-1) was achieved for particles with sizes of 40-130 nm. The superparamagnetic reusable catalyst was found to be active for the selective liquid phase oxidation of alcohols with hydrogen peroxide as a mild oxidant. Nickel hydroxide acted as a Bronsted base working in synergy with the nanoferrite catalyst for alcohol oxidation. The catalytic system was found to catalyse primary and secondary alcohols efficiently (86%) to their corresponding carbonyls in good yields. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2015.Item Nickel hydroxide/cobalt-ferrite magnetic nanocatalyst for alcohol oxidation(2014) Bhat, P.B.; Inam, F.; Bhat, B.R.A magnetically separable, active nickel hydroxide (Br nsted base) coated nanocobalt ferrite catalyst has been developed for oxidation of alcohols. High surface area was achieved by tuning the particle size with surfactant. The surface area of 120.94 m2 g-1 has been achieved for the coated nanocobalt ferrite. Improved catalytic activity and selectivity were obtained by synergistic effect of transition metal hydroxide (basic hydroxide) on nanocobalt ferrite. The nanocatalyst oxidizes primary and secondary alcohols efficiently (87%) to corresponding carbonyls in good yields. 2014 American Chemical Society.Item Nickel hydroxide/cobalt-ferrite magnetic nanocatalyst for alcohol oxidation(American Chemical Society service@acs.org, 2014) Bhat, P.B.; Inam, F.; Badekai Ramachandra, B.R.A magnetically separable, active nickel hydroxide (Brønsted base) coated nanocobalt ferrite catalyst has been developed for oxidation of alcohols. High surface area was achieved by tuning the particle size with surfactant. The surface area of 120.94 m2 g-1 has been achieved for the coated nanocobalt ferrite. Improved catalytic activity and selectivity were obtained by synergistic effect of transition metal hydroxide (basic hydroxide) on nanocobalt ferrite. The nanocatalyst oxidizes primary and secondary alcohols efficiently (87%) to corresponding carbonyls in good yields. © 2014 American Chemical Society.