Research Interests:
Complexes5–7synthesized from twoin situgenerated ligands, HL1and HL2exhibited excellent TON for epoxidation of olefins.
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Research Interests:
The kinetics of the electron-transfer reactions of the manganese(III) complex of trans-cyclohexane-1,2-diamine-N,N,N′,N′-tetraacetate (cdta4–) with two thiols thioglycolic acid and glutathione has been investigated at 30 °C in aqueous... more
The kinetics of the electron-transfer reactions of the manganese(III) complex of trans-cyclohexane-1,2-diamine-N,N,N′,N′-tetraacetate (cdta4–) with two thiols thioglycolic acid and glutathione has been investigated at 30 °C in aqueous media in the range pH 2.0–10.33 with varying reductant concentrations at constant ionic strength, I= 0.20 mol dm–3(NaClO4). The reactions are first order both in complex and reductants and follow the general rate law, –d[MnIII(cdta)–]/dt=Kobs[MnIII(cdta)–]=K[MnIII(cdta)–][reductant]. Both the reactions have been assumed to proceed via an inner-sphere mechanism with support for this coming from the observation of a rapid initial increase in absorption followed by a slower decay. This indicates the formation of an inner-sphere associated species which decomposes unimolecularly leading to the transfer of the electron from the thiol to the oxidant. Additional support for this mechanism comes from a comparison of the water-exchange rate of [Mn(cdta)(H2O)]– with the higher limit of the electron-transfer rates. The pH–rate profiles are bell-shaped curves and were successfully modelled by fitting the experimental data to a computer-fitted program thereby evaluating the reactivity of all the reacting species of the reductants.
Research Interests: Chemistry and Glutathione
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The molecular structure of the title salt, C(11)H(17)N(4)(+).H(2)PO(4)(-), has been determined from single-crystal X-ray analysis and compared with the structure calculated by density functional theory (DFT) at the BLYP level. The crystal... more
The molecular structure of the title salt, C(11)H(17)N(4)(+).H(2)PO(4)(-), has been determined from single-crystal X-ray analysis and compared with the structure calculated by density functional theory (DFT) at the BLYP level. The crystal packing in the title compound is stabilized primarily by intermolecular N-H...O, O-H...N and O-H...O hydrogen bonds and pi-pi stacking interactions, and thus a three-dimensional supramolecular honeycomb network consisting of R(4)(2)(10), R(4)(4)(14) and R(4)(4)(24) ring motifs is established. The HOMO-LUMO energy gap (1.338 eV; HOMO is the highest occupied molecular orbital and LUMO is the lowest unoccupied molecular orbital) indicates a high chemical reactivity for the title compound.
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A mononuclear square planar complex [CuII(L2f)], formed from a Schiff base H2La and Cu2+ with the concomitant oxidation of two –CH2OH groups to aldehyde, displayed catalytic oxidation of aromatic hydrocarbons.
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Research Interests:
A diformyl-p-cresol-8-aminoquinoline based probe exhibits dual colorimetric and fluorogenic properties on selective binding towards Mg2+and Zn2+. This probe could be made selective towards Mg2+over Zn2+in the presence of TPEN.
Research Interests:
Crystal engineering is a rapidly expanding global discipline practiced by scientists with diverse interests in modelling, synthesis, evaluation and utilization of crystalline solids; and research on materials with desired functions and... more
Crystal engineering is a rapidly expanding global discipline practiced by scientists with diverse interests in modelling, synthesis, evaluation and utilization of crystalline solids; and research on materials with desired functions and fascinating topological architectures has become ...
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ABSTRACT Design and synthesis of a triangular manganese compound, [Mn3O4(H2O)2(phen)4](NO3)4 · 3H2O (1) with mono-µ-oxo and di-µ-oxo, is described. The complex has been characterized by elemental analysis, spectroscopy, single crystal and... more
ABSTRACT Design and synthesis of a triangular manganese compound, [Mn3O4(H2O)2(phen)4](NO3)4 · 3H2O (1) with mono-µ-oxo and di-µ-oxo, is described. The complex has been characterized by elemental analysis, spectroscopy, single crystal and powder diffraction measurements, thermogravimetric analysis, etc. Bond Valence Sum calculations and X-ray photoelectron spectroscopy reveal that each manganese at each vertex of the triangle is +IV oxidation state. Variable temperature magnetic measurements show strong antiferromagnetic coupling between metal ions with the following set of parameters: g = 1.99, J 1 = −50.0 cm−1, and J 2 = −90.2 cm−1 (where J 1 describes the interaction across the two mono-µ-oxo bridges and J 2 is the exchange coupling across the di-µ-oxo bridge). The compound breaks down in three steps when heated from room temperature to 900°C. The final ash of the compound is confirmed by infrared spectrum with standard MnO2.
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The kinetics of the oxidation of thiosulfate ion by [Mn(Y)]− (H4Y = trans-cyclohezane-1,2-dimine-N,N,N′,N′-tetraacetic acid) and [Ni(L1)]2+ (HL1 = 15-amino-3-methyl-4,7,10,13-tetraazapentadec-3-en-2-one oxime) have been investigated at... more
The kinetics of the oxidation of thiosulfate ion by [Mn(Y)]− (H4Y = trans-cyclohezane-1,2-dimine-N,N,N′,N′-tetraacetic acid) and [Ni(L1)]2+ (HL1 = 15-amino-3-methyl-4,7,10,13-tetraazapentadec-3-en-2-one oxime) have been investigated at 20.0, 30.0, and 40.0°C in aqueous solution and found to follow the general rate law −d/dt [complex] = kox[S2O32−] [complex]. The large negative entropy (ΔS‡) of activation for the reactions and the results of Marcus calculation provide support for inner-sphere mechanism to be operative. © 1995 John Wiley & Sons, Inc.
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... Dipankar Maity 1 ,; Atish D. Jana 2 ,; Mainak Debnath 1 ,; Nigel GR Hearns 3,4 ,; Ming-Han Sie 5 ,; Hon Man Lee 5 ,; Rodolphe Clérac 3,4 ,; Mahammad Ali 1. ... 2 Department of Physics, Sripat Singh College, Jiaganj, Murshidabad, WB,... more
... Dipankar Maity 1 ,; Atish D. Jana 2 ,; Mainak Debnath 1 ,; Nigel GR Hearns 3,4 ,; Ming-Han Sie 5 ,; Hon Man Lee 5 ,; Rodolphe Clérac 3,4 ,; Mahammad Ali 1. ... 2 Department of Physics, Sripat Singh College, Jiaganj, Murshidabad, WB, 742123, India. 3 ...
Research Interests:
Two novel organic-inorganic hybrid tungsto- and molybdo-telurates having formula [{Na(4)(H(2)O)(14)}{Cu(gly)}(2)][TeMo(6)O(24)] (1){gly = glycine} and [{Cu(en)(2)}(3){TeW(6)O(24)}]·6H(2)O {en = ethyline-diamine} (2) based on Anderson type... more
Two novel organic-inorganic hybrid tungsto- and molybdo-telurates having formula [{Na(4)(H(2)O)(14)}{Cu(gly)}(2)][TeMo(6)O(24)] (1){gly = glycine} and [{Cu(en)(2)}(3){TeW(6)O(24)}]·6H(2)O {en = ethyline-diamine} (2) based on Anderson type heteropolyoxometalates (POMs) have been synthesized and characterized by X-ray crystallography. Common structural feature of both 1 and 2 is the presence of a unique 1D open rack-like architecture, where the disc shaped Anderson POMs act as steps and cationic Cu-organic complexes act as handles of the rack. In 1 the independent structural unit is a 1D coordination polymer with the above mentioned rack type architecture, while in 2, these independent rack-like architectures are further extended to a 2D coordination polymer. Heterogeneous catalysis for the epoxidation of cyclohexene and styrene by complexes 1 and 2 showed very good catalytic efficiency resulting epoxides of ~60% yield, with dialcohol formed by the hydrolysis of epoxides, as the other major product (~28%). Cyclic voltammetric studies of [{Na(4)(H(2)O)(14)}{Cu(gly)}(2)][TeMo(6)O(24)] (1) in aqueous KCl solution indicates that the redox changes occur only on the copper centers and supported by carrying out parallel experiments on the precursors like ([Cu(gly)(2)](2+) and [TeMo(6)O(24)](6-), under the identical experimental conditions. The E(1/2) = 0.662, -0.142 and -0.332 V(vs. SCE) correspond to Cu(III) → Cu(II), Cu(II) → Cu(I) and Cu(I) → Cu(0) reductions, respectively. Thermal analyses reveal identical phase transition reactions with an exothermic peak in the DTA curve at 380 °C for 1 and an endothermic peak appears at comparatively higher temperature (408 °C) for 2 manifesting the higher stability of tungstane based POM over the molybdenum ones. EPR as well as magnetic moment results indicate that both the complexes 1 and 2 are paramagnetic with one unpaired electron per copper(II) ion.
Research Interests:
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Research Interests:
Complexes5–7synthesized from twoin situgenerated ligands, HL1and HL2exhibited excellent TON for epoxidation of olefins.
Research Interests:
Research Interests:
The kinetics of the electron-transfer reactions of the manganese(III) complex of trans-cyclohexane-1,2-diamine-N,N,N′,N′-tetraacetate (cdta4–) with two thiols thioglycolic acid and glutathione has been investigated at 30 °C in aqueous... more
The kinetics of the electron-transfer reactions of the manganese(III) complex of trans-cyclohexane-1,2-diamine-N,N,N′,N′-tetraacetate (cdta4–) with two thiols thioglycolic acid and glutathione has been investigated at 30 °C in aqueous media in the range pH 2.0–10.33 with varying reductant concentrations at constant ionic strength, I= 0.20 mol dm–3(NaClO4). The reactions are first order both in complex and reductants and follow the general rate law, –d[MnIII(cdta)–]/dt=Kobs[MnIII(cdta)–]=K[MnIII(cdta)–][reductant]. Both the reactions have been assumed to proceed via an inner-sphere mechanism with support for this coming from the observation of a rapid initial increase in absorption followed by a slower decay. This indicates the formation of an inner-sphere associated species which decomposes unimolecularly leading to the transfer of the electron from the thiol to the oxidant. Additional support for this mechanism comes from a comparison of the water-exchange rate of [Mn(cdta)(H2O)]– with the higher limit of the electron-transfer rates. The pH–rate profiles are bell-shaped curves and were successfully modelled by fitting the experimental data to a computer-fitted program thereby evaluating the reactivity of all the reacting species of the reductants.
Research Interests: Chemistry and Glutathione
Research Interests:
Research Interests:
The molecular structure of the title salt, C(11)H(17)N(4)(+).H(2)PO(4)(-), has been determined from single-crystal X-ray analysis and compared with the structure calculated by density functional theory (DFT) at the BLYP level. The crystal... more
The molecular structure of the title salt, C(11)H(17)N(4)(+).H(2)PO(4)(-), has been determined from single-crystal X-ray analysis and compared with the structure calculated by density functional theory (DFT) at the BLYP level. The crystal packing in the title compound is stabilized primarily by intermolecular N-H...O, O-H...N and O-H...O hydrogen bonds and pi-pi stacking interactions, and thus a three-dimensional supramolecular honeycomb network consisting of R(4)(2)(10), R(4)(4)(14) and R(4)(4)(24) ring motifs is established. The HOMO-LUMO energy gap (1.338 eV; HOMO is the highest occupied molecular orbital and LUMO is the lowest unoccupied molecular orbital) indicates a high chemical reactivity for the title compound.
Research Interests:
Research Interests:
A mononuclear square planar complex [CuII(L2f)], formed from a Schiff base H2La and Cu2+ with the concomitant oxidation of two –CH2OH groups to aldehyde, displayed catalytic oxidation of aromatic hydrocarbons.
Research Interests:
Research Interests:
A diformyl-p-cresol-8-aminoquinoline based probe exhibits dual colorimetric and fluorogenic properties on selective binding towards Mg2+and Zn2+. This probe could be made selective towards Mg2+over Zn2+in the presence of TPEN.
Research Interests:
Crystal engineering is a rapidly expanding global discipline practiced by scientists with diverse interests in modelling, synthesis, evaluation and utilization of crystalline solids; and research on materials with desired functions and... more
Crystal engineering is a rapidly expanding global discipline practiced by scientists with diverse interests in modelling, synthesis, evaluation and utilization of crystalline solids; and research on materials with desired functions and fascinating topological architectures has become ...
Research Interests:
... cation layer' templated by an Anderson polyoxometallate. Mahammad Ali, Daipayan Dutta, Surajit Biswas, Jaromir Marek and Atish Dipankar Jana CrystEngComm, 2009, 11, 2608-2610. DOI: 10.1039/B910732K , Communication. ...
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ABSTRACT Design and synthesis of a triangular manganese compound, [Mn3O4(H2O)2(phen)4](NO3)4 · 3H2O (1) with mono-µ-oxo and di-µ-oxo, is described. The complex has been characterized by elemental analysis, spectroscopy, single crystal and... more
ABSTRACT Design and synthesis of a triangular manganese compound, [Mn3O4(H2O)2(phen)4](NO3)4 · 3H2O (1) with mono-µ-oxo and di-µ-oxo, is described. The complex has been characterized by elemental analysis, spectroscopy, single crystal and powder diffraction measurements, thermogravimetric analysis, etc. Bond Valence Sum calculations and X-ray photoelectron spectroscopy reveal that each manganese at each vertex of the triangle is +IV oxidation state. Variable temperature magnetic measurements show strong antiferromagnetic coupling between metal ions with the following set of parameters: g = 1.99, J 1 = −50.0 cm−1, and J 2 = −90.2 cm−1 (where J 1 describes the interaction across the two mono-µ-oxo bridges and J 2 is the exchange coupling across the di-µ-oxo bridge). The compound breaks down in three steps when heated from room temperature to 900°C. The final ash of the compound is confirmed by infrared spectrum with standard MnO2.
Research Interests:
The kinetics of the oxidation of thiosulfate ion by [Mn(Y)]− (H4Y = trans-cyclohezane-1,2-dimine-N,N,N′,N′-tetraacetic acid) and [Ni(L1)]2+ (HL1 = 15-amino-3-methyl-4,7,10,13-tetraazapentadec-3-en-2-one oxime) have been investigated at... more
The kinetics of the oxidation of thiosulfate ion by [Mn(Y)]− (H4Y = trans-cyclohezane-1,2-dimine-N,N,N′,N′-tetraacetic acid) and [Ni(L1)]2+ (HL1 = 15-amino-3-methyl-4,7,10,13-tetraazapentadec-3-en-2-one oxime) have been investigated at 20.0, 30.0, and 40.0°C in aqueous solution and found to follow the general rate law −d/dt [complex] = kox[S2O32−] [complex]. The large negative entropy (ΔS‡) of activation for the reactions and the results of Marcus calculation provide support for inner-sphere mechanism to be operative. © 1995 John Wiley & Sons, Inc.
Research Interests:
Research Interests:
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Research Interests:
... Dipankar Maity 1 ,; Atish D. Jana 2 ,; Mainak Debnath 1 ,; Nigel GR Hearns 3,4 ,; Ming-Han Sie 5 ,; Hon Man Lee 5 ,; Rodolphe Clérac 3,4 ,; Mahammad Ali 1. ... 2 Department of Physics, Sripat Singh College, Jiaganj, Murshidabad, WB,... more
... Dipankar Maity 1 ,; Atish D. Jana 2 ,; Mainak Debnath 1 ,; Nigel GR Hearns 3,4 ,; Ming-Han Sie 5 ,; Hon Man Lee 5 ,; Rodolphe Clérac 3,4 ,; Mahammad Ali 1. ... 2 Department of Physics, Sripat Singh College, Jiaganj, Murshidabad, WB, 742123, India. 3 ...
Research Interests:
Two novel organic-inorganic hybrid tungsto- and molybdo-telurates having formula [{Na(4)(H(2)O)(14)}{Cu(gly)}(2)][TeMo(6)O(24)] (1){gly = glycine} and [{Cu(en)(2)}(3){TeW(6)O(24)}]·6H(2)O {en = ethyline-diamine} (2) based on Anderson type... more
Two novel organic-inorganic hybrid tungsto- and molybdo-telurates having formula [{Na(4)(H(2)O)(14)}{Cu(gly)}(2)][TeMo(6)O(24)] (1){gly = glycine} and [{Cu(en)(2)}(3){TeW(6)O(24)}]·6H(2)O {en = ethyline-diamine} (2) based on Anderson type heteropolyoxometalates (POMs) have been synthesized and characterized by X-ray crystallography. Common structural feature of both 1 and 2 is the presence of a unique 1D open rack-like architecture, where the disc shaped Anderson POMs act as steps and cationic Cu-organic complexes act as handles of the rack. In 1 the independent structural unit is a 1D coordination polymer with the above mentioned rack type architecture, while in 2, these independent rack-like architectures are further extended to a 2D coordination polymer. Heterogeneous catalysis for the epoxidation of cyclohexene and styrene by complexes 1 and 2 showed very good catalytic efficiency resulting epoxides of ~60% yield, with dialcohol formed by the hydrolysis of epoxides, as the other major product (~28%). Cyclic voltammetric studies of [{Na(4)(H(2)O)(14)}{Cu(gly)}(2)][TeMo(6)O(24)] (1) in aqueous KCl solution indicates that the redox changes occur only on the copper centers and supported by carrying out parallel experiments on the precursors like ([Cu(gly)(2)](2+) and [TeMo(6)O(24)](6-), under the identical experimental conditions. The E(1/2) = 0.662, -0.142 and -0.332 V(vs. SCE) correspond to Cu(III) → Cu(II), Cu(II) → Cu(I) and Cu(I) → Cu(0) reductions, respectively. Thermal analyses reveal identical phase transition reactions with an exothermic peak in the DTA curve at 380 °C for 1 and an endothermic peak appears at comparatively higher temperature (408 °C) for 2 manifesting the higher stability of tungstane based POM over the molybdenum ones. EPR as well as magnetic moment results indicate that both the complexes 1 and 2 are paramagnetic with one unpaired electron per copper(II) ion.