Subratanath Koner

Jadavpur University, Kolkata, Bengal, India

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Publications (93)178.66 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: NH2 groups of IRMOF-3 have been covalently modified by pyridine-2-aldehyde followed by incorporation of copper. Hybrid system catalyzes O-arylation reaction heterogeneously under green condition.
    Catalysis Communications 01/2015; 58:141–148. · 2.92 Impact Factor
  • Debraj Saha, Tanmoy Maity, Subratanath Koner
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    ABSTRACT: Two alkaline earth metal-based carboxylate systems, [Mg(HL)(H2O)2]n () and [Ca(H2L)2]n () (H3L = chelidamic acid) have been hydrothermally synthesized, and characterized by single-crystal X-ray diffraction, IR, elemental analysis, and thermo-gravimetric analysis. Compound has a 2D structure incorporating two water molecules. The dehydrated species, , generated from by removal of the coordinated water, has been characterized by thermo-gravimetric analysis, IR, elemental analysis and variable temperature powder X-ray diffraction. Both and its dehydrated species catalyze the Claisen-Schmidt reaction under heterogeneous conditions, but is a more effective catalyst under environmentally friendly conditions. The catalyst can readily be recovered and reused in successive cycles without detectable loss of activity. Compound has a 3D structure and is thermally stable up to 540 °C, but is inactive catalytically.
    Dalton Transactions 07/2014; · 3.81 Impact Factor
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    Tanmoy Maity, Debraj Saha, Subratanath Koner
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    ABSTRACT: A highly porous Zn-based metal–organic framework (MOF) IRMOF-3 was covalently decorated with pyridine-2-aldehyde. The free amine group of IRMOF-3 upon condensation with pyridine-2-aldehyde affords a bidentate Schiff-base moiety in the porous matrix. The Schiff base moieties are availed to anchor copper(II) ions to display the catalyst’s utility towards catalytic reactions. The catalyst was characterized by UV/Vis and IR spectroscopy, powder XRD spectrometry, SEM energy-dispersive X-ray spectrometry, and nitrogen sorption measurements. The catalyst exhibits excellent activity in catalyzing the N-arylation reaction of nitrogen-containing heterocycles with aryl bromides in DMSO medium, under mild condition (90 °C) in the presence of Cs2CO3. The porous catalyst demonstrates size selectivity towards substrate as a result of the presence of active sites inside the pores of the MOF. The anchored complex seems to be not leached or decomposed during the catalytic reactions up to five successive catalytic cycles, demonstrating practical advantages over homogeneous catalysis.
    ChemCatChem 07/2014; · 5.18 Impact Factor
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    Soma Das, Susmita Bhunia, Tanmoy Maity, Subratanath Koner
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    ABSTRACT: A highly efficient heterogeneous catalyst has been synthesized by anchoring of palladium(II) into the Schiff-base modified MCM-41. The catalyst has shown unprecedented high conversion in remarkably short time to complete Suzuki cross-coupling reactions. The reaction methodology is very simple, low cost and non-hazardous which can afford an economically and environmentally viable process. The catalyst can be recycled without any significant loss of activity.
    Journal of Molecular Catalysis A Chemical 01/2014; 394:188–197. · 3.19 Impact Factor
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    Debraj Saha, Tanmoy Maity, Soma Das, Subratanath Koner
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    ABSTRACT: Three magnesium based carboxylate framework systems were prepared through a temperature-dependent synthesis. The compounds were synthesized by a hydrothermal method and characterized by single crystal X-ray diffraction analysis. A stepwise increase in the temperature of the medium resulted a stepwise increase in the dimensionality of the network, ultimately leading to the formation of a new 2D layered alkaline earth metal-organic framework (MOF) compound, {[Mg2(HL)2(H2O)4]·H2O}n () (H3L = pyrazole-3,5-dicarboxylate). Compound selectively adsorbs hydrogen (H2) (ca. 0.56 wt% at 77 K) over nitrogen at 1 atm and demonstrates a strong blue fluorescent emission band at 480 nm (λmax) upon excitation at 270 nm. Notably, the 2D framework compound efficiently catalyzes the aldol condensation reactions of various aromatic aldehydes with ketones in a heterogeneous medium under environmentally friendly conditions. The catalyst can be recycled and reused several times without any significant loss of activity.
    Dalton Transactions 08/2013; · 3.81 Impact Factor
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    Debraj Saha, Tanmoy Maity, Rajesh Bera, Subratanath Koner
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    ABSTRACT: a b s t r a c t A new Co(III) Schiff-base complex, [Co(HL) 2 ]NO 3 ÁH 2 O (1) (H 2 L = 1-(N-3-methoxy-salicylideneimino)-eth-ane-2-ol), has been synthesized and characterized by several physicochemical methods. X-ray crystal structure analysis revealed that complex 1 features a distorted octahedral coordination geometry and the metal center is surrounded by two tridented N,O,O-donor Schiff base ligands (HL À). [Co(HL) 2 ]NO 3 ÁH 2 O (1) is capable of activating dioxygen in air to catalyze the epoxidation of various alkenes using isobutr-aldehyde as a co-reductant under homogeneous conditions. It was observed that the yield of the epoxides and their selectivity is highest in acetonitrile medium.
    Polyhedron 04/2013; 56:230-236. · 2.05 Impact Factor
  • Debraj Saha, Rupam Sen, Tanmoy Maity, Subratanath Koner
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    ABSTRACT: An ecofriendly solid catalyst has been synthesized by anchoring palladium(II) into post synthetically modified metal organic framework IRMOF-3. Pore of IRMOF-3 was first modified with pyridine-2-aldehyde. The amine group of IRMOF-3 upon condensation with pyridine-2-aldehyde afforded a bidentate Schiff base moiety in the porous matrix. The Schiff base moieties were used to anchor palladium(II) ions. The prepared catalyst has been characterized by UV-vis, IR spectroscopy, X-ray powder diffraction and nitrogen sorption measurements. Framework structure of the catalyst is not being destroyed in the multistep synthesis procedure as evidenced in X-ray powder diffraction studies. The catalyst has shown high activity towards Suzuki and Stille cross-coupling reaction in 20% H2O/EtOH and EtOH medium, respectively, at 80 °C. The immobilized complex did not leach or decompose during the catalytic reactions, showing practical advantages over the homogeneous catalysis.
    Langmuir 02/2013; · 4.38 Impact Factor
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    ABSTRACT: Reaction of ethanolic solution of hydrated metal salts Mn(NO3)2/Fe(BF4)2 with sodium dicyanamide (dca) and 18-crown-6 ether (18C6) in water results in the isolation of 1:1 associates [Mn(dca)2(H2O)4]·18C6 (1) and [Fe(dca)2(H2O)4]·18C6 (2). Single crystal X-ray structure analysis revealed a high degree of isostructurality between the two 18C6 templated metal complexes (1) and (2) exhibiting second sphere coordination via intermolecular O (water)H⋯O (crown) hydrogen bonds. The octahedral Mn(II)/Fe(II) complexes are sandwiched between adjacent 18C6 molecules into one-dimensional polymeric chains along the [1 0 0] directions, which are further linked through intermolecular O (water)H⋯N (dca) hydrogen bonds, thus forming a two-dimensional supramolecular framework. The electronic structures of the complexes calculated at the DFT level showed a HOMO–LUMO energy separation of 2.45 eV in (1) and 0.83 eV in (2), which implied a higher kinetic stability of complex (1) than that of (2).
    Journal of Molecular Structure 02/2013; 1033:137–144. · 1.40 Impact Factor
  • Satyajit Haldar, Subratanath Koner
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    ABSTRACT: The addition of phenols to aryl-substituted alkynes to form 1,1-diarylalkenes was carried out by using the Fe-Al-MCM-41 catalyst. The catalyst showed remarkable improvement in time and yield in comparison to other solid catalysts. The heterogeneous catalyst can be reused at least three times without a significant loss in activity.
    Beilstein Journal of Organic Chemistry 01/2013; 9:49-55. · 2.80 Impact Factor
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    Tanmoy Maity, a] Debraj Saha, a] Soma Das, Subratanath Koner
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    ABSTRACT: A new 3D alkaline earth metal–organic framework (MOF), [Ba(Hdcp)H2O]n (1) (H3dcp = 3,5-pyrazoledicarboxylic acid), has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction analysis. A crystallographic study reveals that each metal ion in 1 is coordinated by eight O atoms and one N atom. Each 3,5-pyrazoledicarboxylato (Hdcp2–) ligand coordinates to six alkaline earth metal centers through two carboxylate groups, each of which adopts a μ3-η2:η1-bridging coordination mode to afford a 3D network. Thermogravimetric analysis reveals that 1 is thermally stable up to ca. 230 °C. An emission band at ca. 466 nm (λmax) was observed in the photoluminescence spectrum of 1 in the solid state at room temperature. Compound 1 heterogeneously catalyzes the aldol condensation reactions of various aromatic aldehydes with acetone, cyclohexanone, acetophenone, and cyclopentanone.
    Berichte der deutschen chemischen Gesellschaft 10/2012; 2012(30-1):4914. · 2.94 Impact Factor
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    Debraj Saha, Tanmoy Maity, Rupam Sen, Subratanath Koner
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    ABSTRACT: a b s t r a c t A new three-dimensional alkaline-earth metal–organic framework (MOF) compound, [Ba(pdc)] n (1) (H 2 pdc = pyridine-2,5-dicarboxylate), has been hydrothermally synthesized and structurally character-ized by single crystal X-ray diffraction analysis. X-ray single-crystal analysis reveals that each metal ion in compound 1 is coordinated by seven O atoms from seven different carboxylate groups. While each pyridine-2,5-dicarboxylato (pdc 2À) ligand coordinates to seven alkaline earth metal centers through two carboxylate groups adopting l 4 -g 2 :g 2 -bridging and l 3 -g 2 :g 1 -bridging coordination modes to afford a 3D network. Thermogravimetric analysis reveals that compound 1 is thermally stable up to around 560 °C. Compound 1 efficiently catalyzes aldol condensation reactions of various aromatic aldehydes with acetone and cyclohexanone under environment friendly heterogeneous condition, giving remark-able yields (up to 96%) with high selectivity (100%) within a short reaction time (6 h). The catalyst was recycled for five successive runs without significant loss of activity. There was no evidence of leaching of metal ions or no loss of structural integrity of the catalyst during the catalytic reaction.
    Polyhedron 07/2012; 43(1):63. · 2.05 Impact Factor
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    Debraj Saha, Rupam Sen, Tanmoy Maity, Subratanath Koner
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    ABSTRACT: A new three-dimensional alkaline-earth metal-organic framework (MOF) compound, [Mg(Pdc)(H(2)O)](n) (1) (H(2)Pdc = pyridine-2,5-dicarboxylic acid), has been synthesized and structurally characterized by single crystal X-ray diffraction analysis. Compound 1 features a 3D porous framework afforded by the Mg(2)-diad centers through formation of interconnected chair like structural motifs. A nitrogen adsorption study confirms the microporosity of compound 1 with a BET surface area of 211 ± 12 m(2) g(-1). Upon dehydration, the BET surface area of 1 is enhanced to a value of 463 ± 36 m(2) g(-1) due to removal of coordinated water molecule. After rehydration, the compound reverts to its original form as evidenced by powder X-ray diffraction and IR spectroscopic analysis and N(2) sorption measurement. Compound 1 retains its pore structure with a variable BET surface area in several cycles of dehydration and rehydration processes indicating robustness of the framework in [Mg(Pdc)(H(2)O)](n) (1). Compound 1 catalyzes the aldol condensation reactions of various aromatic aldehydes with acetone and cyclohexanone in heterogeneous conditions. Notably, the catalytic activity of the compound is enhanced upon dehydration. The catalyst can be recycled and reused several times without significant loss of activity.
    Dalton Transactions 05/2012; 41(24):7399-408. · 3.81 Impact Factor
  • Rupam Sen, Debraj Saha, Subratanath Koner
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    ABSTRACT: The role of pH in the formation of metal-organic frameworks (MOFs) has been studied for a series of magnesium-based carboxylate framework systems. Our investigations have revealed the formation of five different zero-dimensional (0D) to three-dimensional (3D) ordered frameworks from the same reaction mixture, merely by varying the pH of the medium. The compounds were synthesized by the hydrothermal method and characterized by single-crystal X-ray diffraction. Increase of the pH of the medium led to abstraction of the imine hydrogen from the ligand and a concomitant increase in the OH(-) ion concentration in the solution, facilitating the construction of higher dimensional framework compounds. A stepwise increase in pH resulted in a stepwise increase in the dimensionality of the network, ultimately leading to the formation of a 3D porous solid. A gas adsorption study of the 3D framework compound confirmed its microporosity with a BET surface area of approximately 450 m(2)  g(-1). Notably, the 3D framework compound catalyzes aldol condensation reactions of various aromatic aldehydes with acetone under heterogeneous conditions.
    Chemistry 03/2012; 18(19):5979-86. · 5.93 Impact Factor
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    Debraj Saha, Tanmoy Maity, Tirthankar Dey, Subratanath Koner
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    ABSTRACT: a b s t r a c t Two new copper(II) complexes, [Cu(HL 1)(NO 3)] (1) (H 2 L 1 = 1-(N-ortho-hydroxyacetophenimine)-ethane-2-ol) and {[Mg(H 2 O) 6 ][Cu(pydca) 2 ]Á2H 2 O} n (2) (H 2 pydca = 2,5-pyridine dicarboxylic acid) have been syn-thesized and characterized. X-ray crystal structure analysis reveals that the geometry of complex 1 is square planar, where copper(II) centers are linked through a weak coordination by the nitrate O atoms occupying two axial positions, resulting a helical chain structure. Complex 1 crystallizes in the chiral space group P2 1 . There is no chiral center in the Schiff-base ligand of 1, its helical structure develops due to the formation of a NO 3 À bridged chain through an asymmetric arrangement. Complex 2 is a 1D chain in which the copper(II) ions are connected by bridging carboxylato ligands. The [Mg(H 2 O) 6 ] 2+ moi-ety occupies the inter-chain space. Epoxidation reactions of styrene and substituted styrenes are homo-geneously catalyzed by complexes 1 and 2 with H 2 O 2 as the oxidant.
    Polyhedron 02/2012; 35(1):55. · 2.05 Impact Factor
  • Susmita Bhunia, Debraj Saha, Subratanath Koner
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    ABSTRACT: An ecofriendly solid catalyst has been synthesized by anchoring vanadium(IV) into organically modified MCM-41. First, the surface of Si-MCM-41 was modified with 3-aminopropyl-triethoxysilane (3-APTES), the amine group of which upon condensation with ortho-hydroxy-acetophenone affords a N(2)O(2)-type Schiff base moiety in the mesoporous matrix. The Schiff base moieties were used to anchor oxo-vanadium(IV) ions. The prepared catalyst has been characterized by UV-vis, IR spectroscopy, small-angle X-ray diffraction (SAX), nitrogen sorption, and transmission electron microscopy (TEM) studies. It is observed that the mesostructure has not been destroyed in the multistep synthesis procedure, as evidenced by SAX and TEM measurements. The catalyst has shown unprecedented high conversion as well as para selectivity toward the bromination of hydroxy aromatic compounds using aqueous 30% H(2)O(2)/KBr in water. The reaction proceeds according to the stoichiometric ratio, and the monobrominated product was obtained as the major product using a stoichiometric amount of the bromine source. The immobilized complex does not leach or decompose during the catalytic reactions, showing practical advantages over the free metal complex.
    Langmuir 12/2011; 27(24):15322-9. · 4.38 Impact Factor
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    Rupam Sen, Debraj Saha, Subratanath Koner
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    ABSTRACT: Two lanthanide-based three dimensional metal–organic frameworks (MOF) viz. [Nd(HCOO) 3 ] n (1) and [Pr(HCOO) 3 ] n (2) have been synthesized and charac-terized. Both the compounds have similar structure. In this study we have demonstrated that the compounds are highly efficient in catalyzing epoxidation of various cyclic and linear olefinic substrates. MOF compounds are stable and recyclable under the reaction conditions. Notably, MOF systems are remarkably more active and selective than the corresponding lanthanide oxide in epoxidation reaction of olefins.
    Catalysis Letters 11/2011; 142(DOI 10.1007/s10562-011-0731-y):124. · 2.24 Impact Factor
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    ABSTRACT: [Ru(bpy)(3)](2+) (bpy = 2,2'-bipyridine) ions were entrapped into the cavities of two-dimensional anionic sheet-like coordination polymeric networks of [M(dca)(3)](-) (dca = dicyanamide; M = Mn(II) and Fe(II)). The prepared compounds, {[Ru(bpy)(3)][Mn(dca)(3)](2)}(n) (1) and {[Ru(bpy)(3)][Fe(dca)(3)](2)}(n) (2), were structurally characterized by X-ray single crystal analysis. The spectroscopic properties of the [Ru(bpy)(3)](2+) ion dramatically changed on its entrapment in [M(dca)(3)](-). The [Ru(bpy)(3)](2+) moiety present in 1 and 2 exhibits novel dual photo-emission at room temperature.
    Dalton Transactions 07/2011; 40(26):6952-60. · 3.81 Impact Factor
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    ABSTRACT: A new Gd26 cluster based 3D framework, {[Gd26(μ6-CO3)9(NIC)32(μ3-OH)26](NO3)2·3(H2O)}n (1) (NIC = nicotinato anion) has been prepared through hydrothermal synthesis and characterised by single-crystal X-ray diffraction. The Gd26 clusters are formed by the combination of five distorted cubane cores attached to each other through six Gd3+ ions. The Gd26 clusters are then connected to each other by organic linkers forming a 3D framework. The dimensions of the spherical cluster shell including the organic ligands is around 2.32(4) nm. The compound catalyses the heterogeneous epoxidation of olefinic substrates including α, β-unsaturated ketones.
    Berichte der deutschen chemischen Gesellschaft 06/2011; 2011(18). · 2.94 Impact Factor
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    ABSTRACT: [Cu(diamine)(NO3)2] complexes have been anchored by substituting easily replaceable nitrate ligand with the amine groups of the organic-modified MCM-41. The amine group containing organic moiety (3-aminopropyl)triethoxysilane has been first anchored on the surface of MCM-41 via silicon alkoxide route. Then the [Cu(diamine)(NO3)2] [where diamine = N,N′-dimethyl-1,2-ethanediamine (NN′dmen) N,N-dimethyl-1,2-ethanediamine (NNdmen), and N,N-diethyl-1,2-ethanediamine (NNdeten)] complex was allowed to react with the modified MCM-41 for tethering the complexes onto mesoporous silica matrix. Copper complexes containing different substituted diamine ligands viz. N,N′-dimethyl-1,2-ethanediamine, N,N-dimethyl-1,2-ethanediamine, and N,N-diethyl-1,2-ethanediamine have also been prepared to compare the catalytic efficiency. The prepared catalysts have been characterized by infrared (FT–IR) and UV–vis spectroscopic, electron paramagnetic resonance (EPR), small-angle X-ray diffraction and N2 sorption study. The catalytic efficacy in the epoxidation reaction depends on the bulkiness of the substituted group in diamine. Notably, styrene shows an impressive conversion (94%) with tert-butylhydroperoxide (tert-BuOOH) over the Cu(NNdmen)-MCM-41 catalyst. Whereas, conversion in styrene to styrene-oxide reaction were only 78% and 48% with Cu(NNdeten)-MCM-41 and Cu(NN′dmen)-MCM-41 catalysts, respectively.
    Applied Catalysis A: General. 01/2011; 392(s 1–2):225–232.
  • Susmita Bhunia, Subratanath Koner
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    ABSTRACT: A new hybrid catalyst has been prepared by tethering a nickel(II) Schiff-base complex via post-synthesis modification of mesoporous silica, MCM-41. The Schiff-base has been derived from salicylaldehyde and 3-aminopropyltriethoxysilane (3-APTES) which is chemically anchored on MCM-41 via silicon alkoxide route. The anchored Schiff-bases imposed a stable planar coordination geometry around the central nickel ions. The catalyst has been characterized by elemental analysis, FT-IR, UV–Vis, small angle X-ray diffraction (SAX) and transmission electron microscopy (TEM) studies. The SAX and TEM measurement showed the mesoporosity of the catalyst. The activity of the catalyst has been assessed in the epoxidation of olefins using tert-butyl-hydroperoxide (tert-BuOOH) as oxidant in heterogeneous condition. Immobilized nickel catalyst was found to be catalytically more active and selective compared to the similar type of nickel(II) complex as well as Ni(NO3)2·6H2O in homogeneous media. The catalyst can be recycled and reused several times without significant loss of activity.
    Polyhedron 01/2011; 30(11):1857-1864. · 2.05 Impact Factor

Publication Stats

168 Citations
178.66 Total Impact Points

Institutions

  • 1993–2014
    • Jadavpur University
      • • Department of Chemistry
      • • Department of Physics
      Kolkata, Bengal, India
  • 1993–2010
    • University of Tsukuba
      Tsukuba, Ibaraki, Japan
  • 2001
    • Krishnath College
      Дургапур, Bengal, India
  • 1988–1996
    • Indian Association for the Cultivation of Science
      • Department of Inorganic Chemistry
      Calcutta, Bengal, India