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Nandi M.,Indian Association for The Cultivation of Science | Nandi M.,Integrated Science Education and Research Center | Mondal J.,Indian Association for The Cultivation of Science | Sarkar K.,Indian Association for The Cultivation of Science | And 2 more authors.
Chemical Communications | Year: 2011

Post-synthesis modification of SBA-15 has been carried out to design highly ordered acid functionalized hybrid mesoporous organosilica, AFS-1. This material has been used as an efficient heterogeneous organocatalyst for the syntheses of xanthenes under mild conditions in the absence of any other metal co-catalyst. © 2011 The Royal Society of Chemistry. Source


Verma S.,Indian Institute of Petroleum | Nandi M.,Indian Association for The Cultivation of Science | Nandi M.,Integrated Science Education and Research Center | Modak A.,Indian Association for The Cultivation of Science | And 2 more authors.
Advanced Synthesis and Catalysis | Year: 2011

Novel organic-inorganic hybrid mesoporous materials containing diimine moieties inside the pore wall were used for the grafting of an oxo-vanadium Schiff base complex at the mesopore surface. The prepared catalyst was found to be highly active and selective for the oxidation of a variety of primary, secondary and α-hydroxy carbonyl compounds to the corresponding aldehydes, ketones and 1,2-dicarbonyl compounds using tert-butyl hydroperoxide as oxidant under mild reaction conditions. After completion of the reaction, the catalyst could easily be recovered by simple filtration and could be reused several times without significant change in the catalytic efficiency. Importantly, the catalyst did not show any leaching during the reaction, confirming that the prepared catalyst was truly heterogeneous in nature. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Mishra S.,Visva Bharati University | Bagdi A.K.,Visva Bharati University | Ghosh M.,Visva Bharati University | Sinha S.,Integrated Science Education and Research Center | Hajra A.,Visva Bharati University
RSC Advances | Year: 2014

ZnI2 was found to be an efficient catalyst for the synthesis of indolizine derivatives by a three-component coupling of pyridine-2- carboxaldehyde/quinoline-2-carboxaldehyde, secondary amines, and terminal alkynes in high yields. This protocol is compatible with a wide range of substrates and is expected to find broad applications due to its operational simplicity, shorter reaction time and low cost. A preliminary photophysical study showed that synthesized morpholinopyrrolo[1,2-a]quinolines represent a new class of fluorophore with high quantum yield. © 2014 The Royal Society of Chemistry. Source


Basu-Mallick B.,Saha Institute of Nuclear Physics | Bondyopadhaya N.,Integrated Science Education and Research Center | Banerjee P.,Saha Institute of Nuclear Physics
Nuclear Physics B | Year: 2014

We construct polarized spin reversal operator (PSRO) which yields a class of representations for the BC N type of Weyl algebra, and subsequently use this PSRO to find out novel exactly solvable variants of the BC N type of spin Calogero model. The strong coupling limit of such spin Calogero models generates the BC N type of Polychronakos spin chains with PSRO. We derive the exact spectra of the BC N type of spin Calogero models with PSRO and compute the partition functions of the related spin chains by using the freezing trick. We also find out an interesting relation between the partition functions of the BC N type and A N -1 type of Polychronakos spin chains. Finally, we study spectral properties like level density and distribution of spacing between consecutive energy levels for BC N type of Polychronakos spin chains with PSRO. © 2014 The Authors. Source


Patra A.K.,Indian Association for The Cultivation of Science | Dutta A.,Indian Association for The Cultivation of Science | Pramanik M.,Indian Association for The Cultivation of Science | Nandi M.,Integrated Science Education and Research Center | And 2 more authors.
ChemCatChem | Year: 2014

An efficient procedure for aerobic oxidation of thiols to disulfides catalyzed by new self-assembled hierarchical mesoporous Mn-MFI in the presence of air under solvent-free conditions as well as in aqueous medium is reported. The mesoporosity and Mn4+ loading, together with a highly crystalline microporous pore wall structure of the MFI framework were achieved through a newly designed hydrothermal process. This hydrothermal approach leads to hierarchical self-assembled mesoporous zeolite structures through isomorphous substitution of Si by Mn and Al. It is shown that Mn-containing mesoporous zeolites are capable to form disulfide bonds from thiols in the presence of air. The zeolitic materials were characterized by XRD, field-emission scanning electron microscopy, high-resolution TEM, X-ray photoelectron spectroscopy, 29Si NMR, 27Al NMR, and EPR spectroscopy, as well as AAS analysis and N2 sorption studies. N2 sorption analysis revealed high surface areas and narrow pore size distributions (1.2-6.0 nm) for different samples. The mesoporous Mn-ZSM-5 acted as an efficient heterogeneous catalyst with maximum catalytic activity in the benzenethiol conversion to diphenyldithiol. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

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