Browsing by Author "Nagendra Babu, J."

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    Acetyl oxime/azirine 1, 3-dipole and strategy for the regioselective synthesis of polysubstituted pyrroles via [3 + 2] cycloaddition with alkyne utilizing Fe2O3@cellulose catalyst
    (Elsevier B.V., 2021-09-27T00:00:00) Dwivedi, Kartikey Dhar; Kumar, Bhupender; Reddy, Marri Sameer; Borah, Biplob; Nagendra Babu, J.; Chowhan, L. Raju
    Fe2O3@cellulose catalyzed regioselective [3 + 2] cycloaddition of acetyl oxime with alkynes via 2H?azirines intermediate generated in situ in an aqueous ethanolic medium is described. The methodology is highly regioselective for the synthesis of polysubstituted pyrroles in good yield. The products were isolated without using any column chromatography. The catalyst could be separated by using an external magnet and the recovered catalyst could be reused for four consecutive cycles with negligible loss in its catalytic activity. Broad functional group tolerance, mild reaction condition, easily accessible starting materials, utilization of green reaction medium, recyclability of the catalyst up to further reaction without affecting the outcome of the reaction, gram-scale synthesis are some of the salient features of this strategy. � 2021 The Author(s)
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    Evaluation of synergistic adsorption approach for terbinafine removal by cotton shell powder immobilized zerovalent copper: Adsorption kinetics and DFT simulation
    (Elsevier B.V., 2023-08-30T00:00:00) Kaur, Parminder; Hussain, Khadim; Kumar, Atul; Singh, Janpreet; Nagendra Babu, J.; Kumar, Sandeep
    Cotton shell powder (CS), nano zerovalent copper (nZVC) and cotton shell powder immobilized zerovalent copper (ZVC@CS) were evaluated for their adsorption efficiencies towards terbinafine hydrochloride (TBH), an antifungal drug. The nZVC and ZVC@CS synthesized via one pot redox precipitation method were characterized by FTIR, XRD, BET, FESEM and TGA analysis. The TGA and AAS analysis confirmed the loading of nearly 10% of nZVC on cotton shell powder in ZVC@CS. The effect of operational parameters (pH, adsorbent dose, initial drug concentration, time, etc.) determining the extent of terbinafine hydrochloride adsorption on ZVC@CS were investigated to ascertain the optimal experimental conditions to achieve maximum adsorption efficiencies. To investigate the adsorption behavior of TBH on ZVC@CS, the experimental data were fitted for five different adsorption models viz. Langmuir, Freundlich, Temkin, Redlich-Peterson and Hill isotherms. The TBH adsorption data was best fit with Hill isotherm model indicating cooperative sorption of TBH molecules on ZVC@CS surface. Among the five kinetic equations namely the pseudo-first-order (PFO), the pseudo-second-order (PSO), Elovich model, the intraparticle diffusion model, and Boyd kinetic model used to estimate the adsorption mechanism, the PFO kinetic model give best fit with a good correlation for the physisorption of TBH on ZVC@CS composite. The mechanism of the adsorption process was observed to be complex, consisting of both surface adsorption and pore diffusion. However, the Boyd plot confirms external mass transport as the rate limiting step for the adsorption of TBH on ZVC@CS. The synergistic adsorption of TBH on ZVC@CS was hypothesized, and the idea was supported by structure optimization results from DFT studies. The ZVC@CS exhibits equilibrium TBH adsorption efficiency (qmax) of 285.3 mg.g?1, significantly higher than adsorbents used in literature for the TBH removal. It is suggested that ZVC@CS may serve as sustainable adsorbents for the removal of cationic contaminants from acidic medium. � 2023 Elsevier B.V.
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    Influence of anion induced proton abstraction on Cu(II) adsorption by alginic acid
    (Elsevier B.V., 2015) Vaid, U.; Mittal, S.; Nagendra Babu, J.
    Alginic acid (AA) synthesized by acidification of commercial sodium alginate was investigated for its Cu(II) adsorption efficiency in the presence of different counter ions. The results of batch adsorption studies indicated an adsorption of 169.86 mg/g of Cu(II) by AA in the presence of acetate ions, however, it significantly decreased in the presence of chloride (126.36 mg/g), sulphate (115.24 mg/g) and nitrate (113.28 mg/g) as counter ions. This can be accounted to the tendency of conjugate base (anion) to abstract proton from AA, which determines the extent of deprotonation of carboxylic acid. The FTIR and TGA/DTA studies support the difference in the coordination of carboxylate to Cu(II) in the presence of various counter anions. Acetate showed strong chelate coordination between Cu(II) and AA, whereas in the presence of Cl-, NO3- and SO42 -, Cu(II) was complexed by weak bridging coordination with AA. � 2015 Elsevier B.V.
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    Nanoscale zerovalent iron (nZVI): An efficient heterogeneous catalyst for environment remediation
    (De Gruyter, 2022-05-09T00:00:00) Kumar, Sandeep; Brar, Ravinderdeep Singh; Nagendra Babu, J.; Hussain, Khadim
    [No abstract available]