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Dutta A.K.,Bengal Engineering and Science University | Maji S.K.,Bengal Engineering and Science University | Dutta S.,Budge Budge Institute of Technology
Journal of Molecular Structure | Year: 2012

An oxo-centred, carboxylate bridged trinuclear iron(III) complex [Fe 3(μ 3-O)(O 2CCH 2Cl) 6(H 2O) 3]ClO 4·9H 2O (1·9H 2O) has been synthesized and characterized on the basis of X-ray crystallography, elemental analysis, cyclic voltammetric, UV-vis and IR spectroscopic techniques. Molecular structure has been established by X-ray diffraction analysis and reveals that the complex 1·9H 2O crystallizes in the rhombohedral space group R 3 with a = 18.0070(6) Å, b = 18.0070(6) Å, c = 9.7962(5) Å, α = β = 90.00° and γ = 120.00°. In the highly symmetric trinuclear structure, three iron(III) atoms occupy vertices of equilateral triangle and exhibits a quasi-reversible one-electron reduction at E = +0.337 V vs Ag/AgCl (ΔE p = 0.079 V) due to the [Fe 3(μ 3-O) (O 2CCH 2Cl) 6(H 2O) 3] +/[Fe 3(μ 3-O)(O 2CCH 2Cl) 6(H 2O) 3] couple. In addition, ascending difference between cathodic and anodic peak potentials (ΔE p) with the increasing scan rate confirmed the reduction wave to be quasi-reversible. © 2012 Elsevier B.V. All rights reserved.

Chanda S.,Budge Budge Institute of Technology | De A.,IIEST Shibpur
2016 2nd International Conference on Control, Instrumentation, Energy and Communication, CIEC 2016 | Year: 2016

This paper proposes the development of an intelligent Energy Management System (EMS) at consumer end to utilize the sensitivities of the local renewable generation, battery backup and Plug In Electric Vehicle resources to the changes in grid power input and price of electricity for utility and Demand Response optimization in Smart Micro Grids. In Demand Response usually the price elasticity of demand is considered as per statistical data. In this work the development of an optimized Demand Response(DR) has been depicted for reliable and efficient operation of Micro grids with Smart Communication facility. A housing complex, in the proposed work has been viewed as a future micro-grid and it has been demonstrated that the EMS developed can be effectively programmed to minimize the consumer payment by efficient utility and load management with the assistance of pricing signals from the Smart Grid. The choice of Particle Swarm Optimization(PSO) was compelling for the nonlinear nature of the optimization surface. The results obtained from simulation looked promising from context of future Smart Micro Grids. © 2016 IEEE.

Bhattacharya P.,Indian Association for The Cultivation of Science | Bhattacharya P.,Budge Budge Institute of Technology | Chakravorti S.,Indian Association for The Cultivation of Science
Chemical Physics Letters | Year: 2013

This Letter reports the photophysics of 4,4-diaminodiphenyl sulfone in anionic and cationic reverse micelles (RM). Decreased fluorescence intensity with significant blue shift of intramolecular charge transfer (ICT) fluorescence maximum and longer emission lifetime of the entrapped probe in motionally restricted water nano-pool of anionic RM could be observed. Bi-exponential decay in anionic RM appears due to polarity heterogeneity in the pool. In a nut shell, experiments establish that the probe is anchored in the micellar head group region of anionic RM vis-à-vis far away from the core in cationic RM. Increasing pool size show the opposite effect to the probe. © 2013 Elsevier B.V. All rights reserved.

Dutta S.,Indian Association for The Cultivation of Science | Dutta S.,Budge Budge Institute of Technology | Biswas P.,Bengal Engineering and Science University
Polyhedron | Year: 2012

The mononuclear complex [AlHL] (1) has been prepared using AlCl 3, H 4L and triethylamine in a 1:1:3 ratio (H 4L = 1,1,1,1-tetrakis[(2-salicylaldiminomethyl)]methane). [Al(HL)] crystallizes in the monoclinic space group P2(1)/c. Although H 4L does not emit at room temperature, a remarkable CHEF (Chelation Enhancement of Fluorescence Emission) effect is observed upon the formation of the complex [Al(HL)] (1). When excited at a wavelength of 350 nm, complex 1 emits at 433 nm. Blue emitting aluminum complexes find special importance as far as OLEDs are concerned and complex 1 is one of the best blue emitting compounds to the best of our knowledge. Emission titration of a solution of complex 1 in acetonitrile with Zn 2+, Cd 2+, Hg 2+ and Pb 2+ shows selectivity towards the Zn 2+ ion. Unlike Cd 2+, Hg 2+ and Pb 2+, which quench the emission, Zn 2+ enhances the fluorescence intensity by 1.64-folds. The quenching process follows the Stern-Volmer equation and in order to get an insight of whether the quenching is static or dynamic in nature, lifetime measurements were carried out. Interestingly, mercury was found to follow static quenching, while cadmium, lead and nickel adopted dynamic quenching pathways. © 2012 Elsevier Ltd. All rights reserved.

Dutta S.,Indian Association for The Cultivation of Science | Dutta S.,Budge Budge Institute of Technology | Biswas P.,Bengal Engineering and Science University
Polyhedron | Year: 2012

To mimic the phosphate ester hydrolysis behavior of purple acid phosphatases the heterobimetallic complex [(BNPP)FeIIIL(μ-BNPP) NiII(H2O)](ClO4) (1) has been synthesized from the precursor complexes [FeIII(LH2)(H2O) 2](ClO4)3·3H2O and [Fe III(LH2)(H2O)Cl](ClO4) 2·2H2O. In these compounds, L2- is the anion of the tetraiminodiphenol macrocyclic ligand (H2L), while LH2 is the zwitterionic form in which the phenolic protons are shifted to the two metal-uncoordinated imine nitrogens, and BNPP is bis(4-nitrophenyl)phosphate. The X-ray crystal structure of compound 1 has been determined. The structure of 1 comprises of two edge-shared distorted octahedrons whose metal centers are bridged by two equatorial phenolate oxygens and two axially disposed oxygens of a BNPP ligand. The internuclear Fe⋯Ni distance is 3.083 . The high-spin iron(III) and nickel(II) in 1 are antiferromagnetically coupled (J = -7.1 cm-1; H = -2J S 1·S2) with S = 3/2 spin ground state. The phosphodiesterase activity of 1 has been studied in 70:30 H2O- (CH3)2SO medium with NaBNPP as the substrate. The reaction rates have been measured by varying pH (3-10), temperature (25-50 °C), and with different concentrations of the substrate and complex at a fixed pH and temperature. Treatment of the rate data, obtained at pH 6.0 and at 35 °C, by the Michaelis-Menten approach have provided the following parameters: K M = 3.6 × 10-4 M, Vmax = 1.83 × 10-7 M s-1, kcat = 9.15 × 10-3 s-1. As compared to the uncatalyzed hydrolysis rate of BNPP, the kcat value is 8.3 × 108 times higher, showing that 1 behaves as an excellent model for phosphate ester hydrolysis. © 2011 Elsevier Ltd. All rights reserved.

Halder T.,Budge Budge Institute of Technology | Karmakar P.K.,University of Calcutta
International Journal of Remote Sensing | Year: 2014

Rainfall intensity retrieval from satellite data and its comparison with the meteorological sensors suffer from a lack of data for an optimal time period. The ground-based dual-frequency microwave radiometers at Vale do Paraiba (23° S) and Alcantara (2° S), Brazil, were installed under a project, CHUVA, during 1 November to 1 December 2011 and 7 March to 7 April 2010, respectively. The results show that a 11/2 h interval would be the optimal time period, providing a better accuracy than 30 min, 1 h, and 2 h intervals. The differential method was established for suitably measuring rainfall intensity using the ground-based radiometric method. The results show that the coefficient of determination (ℝ2) values for Vale do Paraiba and Alcantara are 0.86729 and 0.90124; correlation coefficient (r) values are 0.9312 and 0.9493; reduced chi-square (χ2) values are 2.00815 and 21.4865, and the root mean square error (RMSE) values are 0.749 and 0.900, respectively. The differential method in finding the rainfall intensity by statistical analysis was found to be a better choice than using only the brightness temperature method because the atmospheric background and the environmental influence change the brightness temperature, which is due only to the liquid content. On the other hand, ground-based radiometry is a better choice because of the fact that it always measures the downwelling radiation so little inhomogeneity is involved. © 2014 Taylor & Francis.

Maji S.K.,Bengal Engineering and Science University | Dutta A.K.,Bengal Engineering and Science University | Dutta S.,Budge Budge Institute of Technology | Srivastava D.N.,Indian Central Salt and Marine Chemicals Research Institute | And 3 more authors.
Applied Catalysis B: Environmental | Year: 2012

CdS nanoparticles (NPs) with different shapes and sizes (rods and spheres) have been synthesized through decomposition of a newly synthesized precursor complex [Cd(SOCPh) 2Lut 2] using structure-directing solvents such as ethylenediamine (EN), dimethylsulfoxide (DMSO) and ammonia (NH 3). In addition, CdS NPs is also prepared by thermal decomposition of the precursor complex under N 2 atmosphere. The precursor complex is characterized by elemental analyses, TGA, FTIR, UV-vis spectroscopy and single crystal X-ray diffraction. The distorted tetrahedron geometry of the precursor complex has been determined by X-ray diffraction, which crystallizes in monoclinic crystal system of P2(1)/n space group with a=11.0487(17)Å, b=16.396(3), c=15.413(2)Å, α=90.00°, β=109.708(4)°, γ=90.00° and Z=4. The CdS NPs are characterized using powder X-ray diffraction, transmission electron microscopy, BET analyses, UV-vis absorption and photoluminescence spectroscopy. The photo-catalytic activity of CdS NPs is studied by the degradation of Rose Bengal (RB) dye, indicating an excellent photocatalytic activity compared to that of commercial TiO 2. The mechanism behind photocatalytic degradation of RB in presence of CdS NPs is elucidated using terephthalic acid photoluminescence probing technique and evidence have shown that the photogenerated holes to be the predominant active species. This paper also demonstrates the intrinsic peroxidase like activity of CdS NPs toward peroxidase substrates 3,3',5,5'-tetramethyl benzidine (TMB) and hydrogen peroxide. Kinetic analysis indicates that the catalysis by CdS NPs show typical Michaelis-Menten kinetics. Moreover, our synthesized CdS NPs show higher catalytic performances with a higher binding affinity for the substrate TMB than horseradish peroxidase (HRP) and other recently reported nano-mimitics. © 2012 Elsevier B.V.

Saha D.,Jadavpur University | Das S.,Jadavpur University | Karmakar S.,Jadavpur University | Dutta S.,Budge Budge Institute of Technology | Baitalik S.,Jadavpur University
RSC Advances | Year: 2013

A mixed-ligand bimetallic ruthenium(ii) complex of composition [(bpy) 2Ru(H2PyImPhen)Ru(bpy)2](ClO4) 4 (1), where H2PyImPhen = 2,6-di(1H-imidazo[4,5-f][1,10] phenanthrolin-2-yl)pyridine and bpy = 2,2′-bipyridine has been synthesized and characterized using standard analytical and spectroscopic techniques. The X-ray crystal structure of its N-H deprotonated form (2) has been determined which showed that the compound crystallized in monoclinic form with the space group P21/c. The optimized geometrical parameters for the complexes computed both in the gas phase and in solution are reported and compared with the available X-ray data. The absorption spectra, redox behavior and luminescence properties of the complexes were thoroughly investigated. Complex 1 displays strong luminescence at room temperature with lifetimes in the range of 160-500 ns (aerated condition), depending upon the nature of the solvent. The complex is found to undergo one reversible oxidation in the positive potential window and three successive quasi-reversible reductions in the negative potential window. Both the anion and cation binding properties of 1 were thoroughly investigated in acetonitrile solution using absorption, steady state and time-resolved emission spectral studies. The anion sensing studies revealed that the receptor acts as a sensor for F-, AcO- and H 2PO4-. It is evident that in the presence of excess F- and AcO- ion, deprotonation of the imidazole N-H fragments of 1 occurs. Anion-induced lifetime quenching by F- and AcO- and enhancement by H2PO4-, makes the receptor 1 a suitable lifetime-based sensor for selective anions. Coordination of metal ions such as Mn2+, Co2+, Cu 2+ to the secondary coordination sphere of 1 trigger emission quenching, while metal ions having a completely filled d orbital (such as Zn2+, Cd2+ or Hg2+) do not quench; rather some finite enhancement of the fluorescence intensity of the receptor occurs. Density functional theory (DFT) and time-dependent DFT (TD-DFT) study provides insight into the nature of the ground and the excited states involved in absorption and emission transitions. In particular, the changes in the absorption and emission spectral characteristics of 1 on interaction with anions and cations are also reproduced by our calculations. © 2013 The Royal Society of Chemistry.

Bhattacharya P.,Indian Association for The Cultivation of Science | Bhattacharya P.,Budge Budge Institute of Technology | Sahoo D.,Indian Association for The Cultivation of Science | Sahoo D.,Lund University | Chakravorti S.,Indian Association for The Cultivation of Science
Journal of Photochemistry and Photobiology A: Chemistry | Year: 2012

The modulation of already established charge transfer (ICT) emission characteristics of 4,4′-diaminodiphenyl sulfone (Dapsone) in different micelles and also its further alterations due to physicochemical change of micelles in company with added room temperature ionic liquid (IL) have been elucidated in this paper with the help of steady state and time-resolved fluorescence spectroscopy. Dapsone seems to enter inside the cationic micelle beyond interfacial region, as evinced by the emission intensity enhancement and blue shift. In anionic micelle little intensity increase and the blue shift of Dapsone point to the presence of the probe near the interfacial region. From Cu 2+ quenching study it has been confirmed that among the ionic micelles the probe makes shallow penetration in anionic micelle compared to that in cationic micelle. In non ionic surfactants the accessibility of the probe to the ionic quencher increases with increasing chain length. The probe's emission intensity is highest in non ionic Tween 20, but it starts decreasing with increasing alkyl chain length up to Tween 60 and it drastically reduces in Tween 80 nearly same as that in water. IL seems to affect the micellization of anionic, cationic and nonionic micelles differently resulting in shrinking and inflating the micellar size. The calculated rotational relaxation time of the micelle-probe complex is very slow compared to the probe rotation inside micelle. © 2012 Elsevier B.V.

Samanta S.,Bengal Engineering and Science University | Das S.,Bengal Engineering and Science University | Samanta P.K.,Bengal Engineering and Science University | Dutta S.,Budge Budge Institute of Technology | Biswas P.,Bengal Engineering and Science University
RSC Advances | Year: 2013

The diamide ligand 2,6-bis[(N-phenyl)amido]-4-methylphenol (HL) has been used to synthesize a mononuclear copper(ii) complex, [CuL2(DMF) 2] (1). The X-ray crystal structure of this complex reveals that the copper(ii) center is coordinated to the two phenoxides and two amide carbonyl oxygens of the HL ligand and additionally to the amide carbonyl oxygens of two dimethylformamide molecules. This complex was also characterized using UV-Vis and EPR spectroscopy, along with thermal and electrochemical analysis. Complex 1 was then immobilized in a 2-D mesoporous silica matrix. This immobilized complex, 1a, has been characterized using UV-Vis and FT-IR spectroscopy, as well as small angle X-ray diffraction, N2 sorption and TEM. The immobilized complex was found to heterogeneously catalyze the aerobic oxidation of benzylic alcohols to the corresponding aldehydes in the presence of TEMPO, with high turnover numbers and good recyclability for up to four cycles. © 2013 The Royal Society of Chemistry.

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