ANURADHA SINHA
@siliguricollege.org.in
Associate Professor of Chemistry
Siliguri College
RESEARCH, TEACHING, or OTHER INTERESTS
Chemistry, Physical and Theoretical Chemistry, Biochemistry
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Subhajit Debnath, Modhusudan Mondal, Anuradha Sinha, Niloy Roy, Biswajit Ghosh, Kangkan Mallick, Biplab Rajbanshi, Debadrita Roy, Tanusree Ray, Shukdeb Sarkar,et al.
Walter de Gruyter GmbH
Abstract Our modern study is going to inspect new inclusion phenomena between the 1-butyl-2,3-dimethylimidazolium tetrafluoroborate [Bdmim]BF4 ionic liquid (IL) and the host α-Cyclodextrin (α-CD) by a 1:1 ratio and newly formed inclusion complex was further explored by the 1H-NMR, FT-IR, UV–vis spectroscopy, PXRD, DSC, and SEM analysis. Molecular docking was also performed to investigate the encapsulation of the inclusion complex in which orientation and it have been seen that the IL [Bdmim]BF4 enters into the α-CD cavity with a 1:1 ratio was further established with the help of Job’s plot. Furthermore, the antibacterial activity of [Bdmim]BF4 IL and its inclusion complex was verified against some Gram-positive and Gram-negative bacterial strains.
Sukdev Majumder, Anuradha Sinha, Debadrita Roy, Biswajit Ghosh, Narendra Nath Ghosh, Tanusree Ray, Vikas Kumar Dakua, Anupam Datta, Indu Bhusan Sarkar, Subhankar Choudhury,et al.
American Chemical Society (ACS)
Here, we have investigated some physicochemical parameters to understand the molecular interactions by means of density (ρ) measurement, measurement of viscosity (η), refractive index(nD) measurement, and conductance and surface tension measurements between two significant aqueous ionic liquid solutions: benzyl trimethyl ammonium chloride (BTMAC) and benzyl triethyl ammonium chloride (BTEAC) in an aqueous l-methionine (amino acid) solution. The apparent molar volume (Φv), coefficient of viscosity (B), and molar refraction (RM) have been used to analyze the molecular interaction behavior associated in the solution at various concentrations and various temperatures. With the help of some important equations such as the Masson equation, the Jones–Doles equation, and the Lorentz–Lorenz equation, very significant parameters, namely, limiting apparent molar volumes (Φv0), coefficient of viscosity (B), and limiting molar refraction (RM0), respectively, are obtained. These parameters along with specific conductance (κ) and surface tension (σ) are very much helpful to reveal the solute–solvent interactions by varying the concentration of solute molecules and temperature in the solution. Analyses of Δμ10#, Δμ20#, TΔS20#, ΔH20#, and thermodynamic data provide us valuable information about the interactions. We note that l-Met in 0.005 molality BTEAC ionic liquid at 308.15 K shows maximum solute–solvent interaction, while l-Met in 0.001 molality BTMAC aqueous solution of ionic liquid at 298.15 K shows the minimum one. Spectroscopic techniques such as Fourier transform infrared (FTIR), 1H-NMR, and UV–vis also provide supportive information about the interactions between the ionic liquid and l-methionine in aqueous medium. Furthermore, adsorption energy, reduced density gradient (RDG), and molecular electrostatic potential (MESP) maps obtained by the application of density functional theory (DFT) have been used to determine the type of interactions, which are concordant with the experimental observations.
Biswajit Ghosh, Anuradha Sinha, Niloy Roy, Biplab Rajbanshi, Modhusudan Mondal, Debadrita Roy, Annwesha Das, Narendra Nath Ghosh, Vikas Kumar Dakua, and Mahendra Nath Roy
Elsevier BV
Mahendra Nath Roy, Kalipada Sarkar, and Anuradha Sinha
Springer Science and Business Media LLC
Anuradha Sinha, Gargi Ghosh, and Mahendra Nath Roy
Informa UK Limited
Systems of 1,3-dioxolane and isoamyl alcohol complexed with sodium tetraphenylborate (NaBPh4) are examined using electrical conductance measurements and FTIR spectroscopy at 298.15 K. The conductance data has been analysed by the Fuoss conductance–concentration equation in terms of the limiting molar conductance (Λ0), the association constant (K A) and the distance of closest approach of ions (R). The observed molar conductivities were explained by the formation of ion-pairs (M+ + X− ↔ MX). Cation–anion interactions along with the hydrogen bonding interactions are investigated by evaluating the frequency shifts of the solvents in the pure state as well as their binary mixtures upon complexation with the salt.
Anuradha Sinha, Arijit Bhattacharjee, and Mahendra Nath Roy
Informa UK Limited
The FTIR spectra of tetrapentylammonium bromide (Pe4NBr), tetrapentylammonium iodide (Pe4NI), tetrahexylammonium bromide (He4NBr), tetrahexylammonium iodide (He4NI), tetraheptylammonium bromide (Hp4NBr), and tetraheptylammonium iodide (Hp4NI) in pure acrylonitrile were observed at 0.1(M), 0.08(M), 0.05(M), and 0.02(M) concentrations. The region of immobilized solvent resulting from the structure-making effects of electrostriction increases with increase in charge-surface ratio of the ions. Cation-anion interactions are thus investigated by evaluating the frequency shifts of the solvent in the pure state upon complexation with the salt.
Anuradha Sinha and Mahendra Nath Roy
Elsevier BV
Anuradha Sinha and Mahendra Nath Roy
Informa UK Limited
Electrical conductance measurements are reported for sodium iodide (NaI) in water + tetrahydrofuran (THF) and water + 1,4-dioxane binary mixtures at 298.15 K. The conductance data have been analyzed by the Fuoss conductance–concentration equation in terms of the limiting molar conductance (Λ 0), the association constant (K A) and the distance of closest approach of ions (R). Furthermore, the conductance data for pure THF have also been analyzed by the Fuoss–Kraus theory and the values of the ion-pair and triple-ion formation constants are calculated.
Anuradha Sinha and Mahendra N. Roy
American Chemical Society (ACS)
The densities and viscosities of ammonium acetate, potassium acetate, sodium acetate, and lithium acetate have been measured in 10, 20, and 30 mass % of tetrahydrofuran + methanol binary solvent mixtures at (303.15, 313.15, and 323.15) K. Apparent molar volumes (Vφ), partial molar expansibility (E2), viscosity B-coefficients, and free energy of activation for viscous flow (Δμ0*) are obtained from these data. The limiting apparent molar volumes (Vφ0) and experimental slopes ( ) derived from the Masson equation have been interpreted in terms of ion−solvent and ion−ion interactions, respectively. The viscosity data have been analyzed using the Jones−Dole equation, and the derived parameters B and A have also been interpreted in terms of ion−solvent and ion−ion interactions. The sound speeds measured at 303.15 K have been used to study the apparent molal isentropic compressibility (KS,φ), intermolecular free length (Lf), relative association (RA), relaxation strength (r‘), and specific acoustic impedance (Z) ...
Anuradha Sinha and Mahendra Nath Roy
Informa UK Limited
Densities and viscosities for the ternary liquid mixtures of water + ethylene glycol +tetrahydrofuran, water + ethylene glycol + 1,4-dioxane, water + ethylene glycol + N,N-dimethylformamide and water + ethylene glycol + dimethyl sulphoxide have been measured as a function of the composition at 298.15, 308.15 and 318.15 K. From the experimental measurements, viscosity deviations (Δη), antagonic index (I A) and excess molar volumes (V E) have been evaluated. The speeds of sound have been also measured and excess isentropic compressibilities ( ) are calculated at 298.15 K. The results are discussed and interpreted in terms of molecular package and specific interaction predominated by hydrogen bonding.
Mahendra Nath Roy and Anuradha Sinha
Elsevier BV
Mahendra Nath Roy, Anuradha Sinha, and Biswajit Sinha
Springer Science and Business Media LLC
M. Nath Roy, B. Sinha, R. Dey, and A. Sinha
Springer Science and Business Media LLC