East Calcutta Girls College

Kolkata, India

East Calcutta Girls College

Kolkata, India

Time filter

Source Type

Dasgupta R.,Vidyasagar College | Dasgupta R.,East Calcutta Girls College | Patel P.P.,Presidency University of India
Geographical Research | Year: 2017

The physical-human dichotomy in geography is long standing, revolving around the topics studied and outlooks adopted by the two groups of geographers. Three reasons are identified for its continuation—the present structure of academic geography, constrained interactions between physical and human geographers, and their publication strategies. Critics suggest that physical and human geography have become divergent strains because the physical environment has been accorded little relevance in human geographic studies, also putting forward the failure of physical geographers to integrate the human influence on physical processes and neglecting space in their studies. Citing examples, this paper argues that physical and human geography influence each other. It also demonstrates that physical geographers have sufficiently considered both space and time, and even space-time, through the concepts of scale and ergodicity. Some measures have been proposed to resuscitate the links between these two branches. These are reconnecting university and school geography, merging departments, teaching courses on geographical philosophies and theory building, engaging in integrative discourses, innovative classroom strategies, joint fieldwork, using geoinformatics, and conducting collaborative research. The paper concludes that physical and human geographers must communicate with each other more and engage in cross-disciplinary studies. Otherwise, they might undermine their responsibilities as geographers and spatial thinkers/analysts. © 2017 Institute of Australian Geographers


Dasgupta R.,University of Cincinnati | Dasgupta R.,East Calcutta Girls College | Crowley B.E.,University of Cincinnati | Barry Maynard J.,University of Cincinnati
Archives of Environmental Contamination and Toxicology | Year: 2017

Most studies on roadside soil pollution have been performed in areas where petrol is the main fuel. Very little work has been conducted in regions where diesel predominates. We collected soil samples from four sites that span a precipitation gradient along the Manali-Leh Highway in northwestern Himalaya, India. This road traverses rough terrain and most of the vehicles that travel along it are diesel-driven. At each site, we collected samples at incremental distances from the highway (0, 2, 5, 10, 20, and 150 m), and at each distance we collected samples from three depths (3, 9, and 15 cm). We assessed the concentrations of 10 heavy metals (Al, Fe, Cr, Cu, Pb, Ni, Co, Zn, V, and Ba), total sulphur, and total organic carbon (TOC) at each distance, and we measured the concentration of 16 polycyclic aromatic hydrocarbons (PAHs) at 2 m from the highway. Overall, we found that metal concentrations are low and there is no relationship between concentrations and distance from the highway, or depth within the soil profile. Sulphur concentrations, on the other hand, are high in roadside soils and there is a negative relationship between concentration and distance from the highway. PAH concentrations are low, but the proportion of different ringed species suggests that their source is anthropogenic. Correlations between TOC and the various pollutants further suggest that diesel vehicles and potentially biomass combustion are starting to affect the roadside environment in remote northwestern India. We suggest that pollutant concentrations be regularly monitored. © 2017 Springer Science+Business Media New York


Pattanayak P.,Kalyani University | Pratihar J.L.,Kandi Raj College | Patra D.,East Calcutta Girls College | Lin C.-H.,Chung Yuan Christian University | And 3 more authors.
Journal of Coordination Chemistry | Year: 2013

The reactions of HL1 [2-((2-(benzylthio)phenylimino)methyl) phenol] and HL2 [3-((2-(benzylthio)phenylimino)methyl)-2-hydroxy-5- methylbenzaldehyde] separately with Cu(OAc)2·H2O afforded new Cu(II) complexes [Cu(L1)(OAc)] (1) and [Cu(L 2)2] (2), respectively. These are characterized by microanalytical data and spectroscopic studies. UV-vis spectra of the complexes show intense low-energy transitions ∼ 420 nm which are ligand to metal charge transfer (LMCT) transitions. The single-crystal X-ray structures were determined for 1 and 2. Reactions of [Cu(L1)(OAc)] (1) with, SCN - and show the replacement of weakly coordinated acetate yielding [Cu(L1)(N3)], [Cu(L1)(SCN)] and [Cu(L 1)(NO2)], respectively. Unequivocal characterization of the substituted products has been done by single-crystal X-ray study of [Cu(L1)(N3)]. HL2 and its Cu(II) complex exhibited low-intensity emission bands at ∼575 nm upon excitation at 375 nm and at 420 nm, respectively. Redox properties of the complexes were determined electrochemically. Density functional theory (DFT) computations have been carried out to explain the spectroscopic and redox properties of the complexes. © 2013 Taylor & Francis.


Pattanayak P.,Kalyani University | Pratihar J.L.,Kandi Raj College | Patra D.,East Calcutta Girls College | Lin C.-H.,Chung Yuan Christian University | And 2 more authors.
Polyhedron | Year: 2013

Ligand, HL, 2-((2-(benzylthio)phenylimino)methyl)phenol, upon reaction with Co(NO3)3·6H2O, Ni(OAc) 2·4H2O and PdCl2 separately afforded complexes [(L)2Co]NO3 (1), [(L)2Ni] (2) and [(L)PdCl] (3) respectively. The new complexes were characterized by usual spectroscopic studies like UV-Vis, IR and NMR and authenticated by X-ray structure determination on [(L)2Co]NO3, [(L) 2Ni]. The analysis of crystal structures revealed that in all the complexes the ligand HL binds the metal center as uni-negative anion; L - dissociating phenolic proton and offers (O, N, S) tridentate binding mode to the metal. The compound [Co(L)2]NO3 is tested for in vitro antibacterial activity. Complex 3, acts as a catalyst in Heck reaction for a number of substrates. Complexes 1 and 2 exhibited a quasi reversible oxidative responses at 0.97 and 0.85 V, respectively, versus SCE. The electronic spectra and redox properties of the complexes have been explained with DFT computation. © 2013 Elsevier Ltd. All rights reserved.


Patra D.,Kalyani University | Patra D.,East Calcutta Girls College | Pattanayak P.,Kalyani University | Pratihar J.L.,Kalyani University | And 2 more authors.
Polyhedron | Year: 2013

The reactions of 1-{[2-(arylazo)phenyl]iminomethyl}-2-naphthol, H 2Lnap [where H represents the dissociable proton upon complexation and aryl groups of H2Lnap are phenyl for H2L1 nap; p-methyl phenyl for H 2L2 nap and p-chloro phenyl for H 2L3 nap] with nickel acetate tetra hydrate or disodium tetrachloropalladate in methanol afforded M-C(aryl) bonded species of composition [M(Lnap)] (M = Ni(II) and Pd (II)). The dinegative (Lnap)2- ligands bind the Ni(II) or Pd(II) in tetradentate (C, N, N, O) fashion in distorted square planar geometry. Ligands and complexes were characterized by spectroscopic methods. The X-ray structures of H 2L1 nap, [Ni(L1 nap)] and [Pd(L1 nap)] were determined to authenticate the characterization. Reactions with metachloroperbenzoic acid (mCPBA), TBHP and hydrogen peroxide leading to oxygen insertion into the M-C bond have been examined. Luminescent properties of ligands and complexes have been reported. © 2012 Elsevier Ltd. All rights reserved.


Pattanayak P.,Kalyani University | Pratihar J.L.,Kalyani University | Pratihar J.L.,Kandi Raj College | Patra D.,Kalyani University | And 3 more authors.
Polyhedron | Year: 2013

The 2-((2-benzylamino)phenyldiazenyl)phenol, H2OL [where H 2OL = ArOHN = NC6H4N(H)CH2(C 6H5); Ar = C6H5 (for H2OL1), p-MeC6H4 (for H2OL2) or p-ClC 6H4 (for H2OL3)], ligands were prepared by the reaction of the appropriate 2-((2-hydroxyaryl)azo)anilines with benzyl bromide. The reactions of Na2PdCl4 with H 2OL afforded tetranuclear Pd(II) complexes of the composition [Pd(OL)]4. The ligands bind palladium(II) in a tridentate (N, N, O) fashion. The X-ray structure of [Pd(OL1)]4 was determined to confirm the characterization. The newly synthesized [Pd(OL1)] 4 complex was utilized as a catalyst for the Suzuki and Heck reaction for a variety of substrates. © 2013 Elsevier Ltd. All rights reserved.


Pattanayak P.,Kalyani University | Pratihar J.L.,Kandi Raj College | Patra D.,East Calcutta Girls College | Brandao P.,University of Aveiro | And 2 more authors.
Polyhedron | Year: 2013

The newly designed multidentate ligand HL, derived from 2-(benzylthio)aniline and 2-hydroxy-5-methylbenzene-1,3-dialdehyde, upon reaction with Cu(II) perchlorate in methanol yielded the binuclear Cu(II) complex [Cu2(L)(μ-OH)](ClO4)2 (1), which was authenticated by single crystal X-ray diffraction. The diffraction analysis revealed that the ligand binds each of the two Cu(II) centers in an (O, N, S) fashion in a distorted square pyramidal geometry where the two copper centers are bridged by μ-phenoxo and μ-hydroxo oxygen atoms. The apical position of one copper center is coordinated by one perchlorate ion and the other center by a water molecule. The packing of the molecule is stabilized through OH 2â̄O hydrogen bonds, mediated through solvent water and perchlorate anions. The emission and redox properties of both the ligand and the complex were examined. The electronic spectra and redox properties of the complex have been explained with DFT computations. The complex [Cu 2(L)(μ-OH)](ClO4)2 shows very good catalytic activities towards the oxidation of benzyl alcohol to benzaldehyde and organic thioethers to the corresponding sulfoxide and sulfones using H2O 2 as the oxidant. © 2013 Elsevier Ltd. All rights reserved.


Pattanayak P.,Kalyani University | Pratihar J.L.,Kandi Raj College | Patra D.,East Calcutta Girls College | Brandao P.,University of Aveiro | Felix V.,University of Aveiro
Inorganica Chimica Acta | Year: 2014

Newly designed tridentate ligand, HL 1 derived from 2-(benzylthio)aniline and 2-hydroxy-1-naphthaldehyde, upon reaction with Cu(II), Ni(II) and Co(III) nitrate separately in methanol yielded binuclear Cu(II) complex, [Cu 2(L)2(NO3)2] 2, and mononuclear [Ni(L)2] 3 and [Co(L)2](NO3) 4 which were characterized by spectral data and authenticated by single crystal X-ray diffraction of 2 and 3. The diffraction analysis revealed that the ligand binds to metals in (O, N, S) fashion. Single crystal X-ray diffraction studies confirmed that the [Cu2(L)2(NO3)2] complex consist of centrosymmetric binuclear entities containing square-pyramidal copper(II) ions bridged through the phenoxo oxygen atoms. The emission and redox properties of both the ligand and corresponding complexes were examined. The redox property of the complexes has been qualitatively explained by single point DFT calculations. The catalytic activities of Cu(II) complex [Cu2(L)2(NO3)2] towards oxidation of benzyl alcohol derivatives to carbonyl compounds was tested using H2O2 as the oxidant. © 2014 Elsevier B.V. All rights reserved.


Pattanayak P.,Kalyani University | Patra D.,East Calcutta Girls College | Lin C.-H.,Chung Yuan Christian University | Pratihar J.L.,Kalyani University | Pratihar J.L.,Kandi Raj College
Journal of Chemical Research | Year: 2012

The complex [CuL 2(OClO 3) 2] [L=2-(benzylthio)aniline] has been synthesised and its crystal structure determined. It displays a one-electron reductive response at -0.38 V versus SCE and its reactions with N 3 -?and SCN-?ions give [CuL 2(N 3) 2] and [CuL 2(SCN) 2]. The copper atom in [CuL 2(OClO 3) 2] assumes a tetragonally distorted, octahedral geometry with two semicoordinated perchlorate oxygens in the axial positions. Two perchlorate ions are also linked to the amino nitrogen of other molecules by intermolecular hydrogen bonding. A plausible description of redox orbitals is given on the basis of single point density functional theory calculations.


Pattanayak P.,Kalyani University | Patra D.,East Calcutta Girls College | Brandao P.,University of Aveiro | Mal D.,University of Aveiro | Felix V.,University of Aveiro
Inorganic Chemistry Communications | Year: 2015

Reaction of ligand, L-CH2Ph with Pd(CH3CN)2Cl2 in acetonitrile in presence of PPh3 and subsequent addition of NaClO4 yielded Pd(II) complex, [Pd(L)(PPh3)](ClO4) 1 due to the SC (CH2Ph) bond cleavage during complexation. Complex 1 was characterized by spectral analysis and the structure was authenticated by single crystal X-ray diffraction. The diffraction analysis revealed that the monoanionic ligand binds with palladium (II) in (N, N, S) fashion in a distorted square planar geometry where the fourth position is occupied by one tri phenyl phosphine group. One ClO4 - ion satisfies the charge of the former aggregate, [Pd(L)(PPh3)]+. The complex [Pd(L)(PPh3)](ClO4), 1 exhibits a very good catalytic activity towards CC bond formation. © 2015 Elsevier B.V. All rights reserved.

Loading East Calcutta Girls College collaborators
Loading East Calcutta Girls College collaborators