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Item From 2011 to 2022: The development of pyrazole derivatives through the ?,?-unsaturated carbonyl compounds(HeteroCorporation, 2023-11-25T00:00:00) Sharma, Shubham; Singh, Virender; Vaishali; Kumar, Rakesh; Jamra, Rahul; Banyal, Naveen; JyotiThe synthesis of pyrazole derivative using ?,?-unsaturated carbonyl compounds has attracted increasing attention of the synthetic organic chemist community. Interestingly, the simplicity of the synthetic method, high reactivity, and ease of incorporating diversity into the desired prototype have contributed a lot toward the exploration of ?,?-unsaturated carbonyl compounds by various research groups. Due to the tremendous pharmacological significance of pyrazole derivatives, their synthesis has been one of the leading research frontiers in recent years. As prime examples, sildenafil, zometapin, Celebrex, and rimonabant have been successfully commercialized in the market to treat various life-challenging diseases. Considering the great profile of ?,?-unsaturated carbonyl compound in the synthesis of biologically active pyrazole derivatives, this review incorporates contemporary literature (2011�2022) on the synthesis of pyrazole and its derivatives using ?,?-unsaturated carbonyl compound as a starting precursor. � 2023 Wiley Periodicals LLC.Item Reduced and oxidized rice straw biochar for hexavalent chromium adsorption: Revisiting the mechanism of adsorption(Elsevier Ltd, 2023-11-01T00:00:00) Dahiya, Amarjeet; Bhardwaj, Akanksha; Rani, Archana; Arora, Meenu; Babu, J. NagendraSurface oxygen functional groups of biochar were tuned by oxidation and reduction of biochar for establishing Cr(VI) adsorption mechanism. Oxygen functional groups (OFGs) on the surface of leached rice straw biochar (LBC4-6) obtained from pyrolysis at 400, 500 and 600 �C, were oxidized to furnish OBC4-6 using modified Hummer's method. Reduced biochar RBC4-6 were obtained by esterification and NaBH4/I2 reduction of oxidized biochar (OBC4-6). The modified biochar were characterized by increase in O/C and H/C ratio, respectively, in case of OBC4-6 and RBC4-6. The Cr(VI) adsorption by modified biochar LBC4-6, OBC4-6, and RBC4-6 showed optimum conditions of pH 3 and dose 0.1 g/L with a good non-linear fit for Langmuir & Freundlich isotherm. The maximum adsorption (Qm) followed the trend: OBC4 (17.47 mg/g) > RBC4 (15.23) > OBC5 (13.23) > LBC4 (10.23) > RBC5 (9.83) > OBC6 (9.60) > RBC6 (7.24) > LBC5 (6.32) > LBC6 (5.98). The adsorption kinetics for adsorption of Cr(VI) on to modified biochar fits pseudo second order (PSO), Elovich and intraparticle diffusion kinetics, showing a chemisorptions in case of biochar L/O/RBC4-6. The lower temperature modified biochar O/RBC4 show better Cr(VI) adsorption. X-ray Photoelectron Spectroscopy (XPS) studies establish optimum OFGs for reduction of Cr(VI) and chelation of the reduced Cr(III). Adsorption and stripping cycles show the oxidized and reduced biochar as better adsorbents with excellent stripping of Cr up to >98 % upon desorption with 1 M NaOH. � 2023Item Efficient synthesis and mechanistic insights for the formation of imidazo[1,2-a]pyridines via multicomponent decarboxylative coupling using chitosan-supported copper catalysts(Elsevier B.V., 2023-10-03T00:00:00) Kaur, Pavneet; Gurjar, Kamlesh K.; Arora, Tania; Bharti, Divya; Kaur, Manpreet; Kumar, Vinod; Parkash, Jyoti; Kumar, RakeshAn efficient multicomponent decarboxylative coupling of 2-aminopyridines, aldehydes and alkynoic acids for the synthesis of imidazo[1,2-a]pyridines was developed using recyclable chitosan-supported copper (chit@CuSO4) as a heterogeneous catalyst. Computational and experimental evidence revealed that in situ generated propargylamine undergoes cyclization to the desired imidazopyridine via prototropic isomerization involving allene type intermediates. Control experiments on isolated propargylamine demonstrated that cyclization could proceed without any metal catalyst. In literature, the cyclization step is assumed to be facilitated by metal catalyst and experimental proof for the involvement of actual intermediates is not available. The synthesized imidazopyridines were further evaluated for antiproliferative activity against human neuroblastoma cells (SHSY-5Y) using MTT assay. � 2023 Elsevier B.V.Item Tetracycline removal via three-way synergy between pistachio shell powder, zerovalent copper or iron, and peroxymonosulfate activation(Elsevier B.V., 2023-10-20T00:00:00) Kaur, Parminder; Kumar, Atul; Babu, J. Nagendra; Kumar, SandeepPistachio shell powder (PS) immobilized zerovalent iron and zerovalent copper (ZVI@PS and ZVC@PS) were investigated for the tetracycline (TCH) removal via sulfate radical based advanced oxidation process (S-AOP's). Eco-efficient ZVI@PS and ZVC@PS nanocomposite prepared by one-pot redox precipitation method were characterized by using FTIR, XRD, SEM, BET, TGA/DTA, and XPS techniques. The EDX, TGA, and AAS analysis techniques confirmed the loading of 44 % Fe and 40 % Cu (w/w %) onto the pistachio shell biomass in ZVI@PS and ZVC@PS nanocomposites, respectively. This report comprehensively discusses the effect of various contributing factors for the TCH removal via advanced oxidation processes such as catalytic dosage, initial pH, PMS dosage and initial TCH concentrations, etc. Besides that, the role of reactive oxygen species (SO4?,.OH, O2?, and 1O2) in the TCH degradation process was investigated using radical scavenging experiments. A three-way synergistic approach was established between adsorption efficiencies of pistachio shell powder, heterogeneous ZVI or ZVC mediated Fenton-process and enhanced PMS activation process, for the observed enhanced TCH degradations. The observed rate constant (kobs.) values of ZVI@PS-PMS (0.34 min?1) and ZVC@PS-PMS (0.16 min?1) processes for TCH removal suggests that the ZVI@PS was more efficient in TCH removal compared to ZVC@PS. � 2023 The Author(s)Item Synthesis and Characterization of Novel Pd@rGO?CuFe2O4 Magnetic Nanoparticles: A Recyclable Catalyst for C?C Coupling Reaction in Biomass-Derived Organic Solvent(John Wiley and Sons Inc, 2023-10-06T00:00:00) Teli, Yaqoob A.; Reetu, Reetu; Singh, Priyanka Gurdev; Patel, Mayur Jagdishbhai; Dash, Sonali; Paine, Snehangshu; Prabhakar, Poornachandra Shamanna; Singh, Virender; Keremane, Kavya S.; Al-Zaqri, Nabil; Mukherjee, Kalisadhan; Dutta, Saikat; Malakar, Chandi C.Development of new, cost effective, stable heterogeneous catalyst for the organic transformations is an important thematic area of research. Present work describes the development of new Pd@rGO?CuFe2O4 catalyst and demonstrates its effectiveness for Suzuki-Miyaura type coupling reactions. The additional advantage of this reaction is its feasibility using biomass-derived solvent like ?-Valerolactone (GVL) in aqueous media. The catalyst is prepared hydrothermally and characterized using XRD, FESEM, EDX, and XPS analysis. The catalyst exhibits excellent activity and recyclability (up to six times) in the C?C coupling reaction to deliver the corresponding biaryl molecules in yields up to 90 %. High efficiency for the conversion of nitriles to amides is also revealed by the prepared catalyst. � 2023 Wiley-VCH GmbH.Item Single-molecule analysis of osmolyte-mediated nanomechanical unfolding behavior of a protein domain(Elsevier B.V., 2023-09-16T00:00:00) Bajaj, Manish; Muddassir, Mohd; Choi, Bumjoon; Singh, Priyanka; Park, Jong Bum; Singh, Surjeet; Yadav, Manisha; Kumar, Rajesh; Eom, Kilho; Sharma, DeepakThe small organic molecules, known as osmolytes being ubiquitously present in different cell types, affect protein folding, stability and aggregation. However, it is unknown how the osmolytes affect the nanomechanical unfolding behavior of protein domain. Here, we show the osmolyte-dependent mechanical unfolding properties of protein titin immunoglobulin-27 (I27) domain using an atomic force microscopy (AFM)-based single-molecule force spectroscopy. We found that amines and methylamines improved the mechanical stability of I27 domain, whereas polyols had no effect. Interestingly, glycine betaine (GB) or trimethylamine-N-oxide (TMAO) increased the average unfolding force of the protein domain. The kinetic parameters analyzed at single-molecule level reveal that stabilizing effect of osmolytes is due to a decrease in the unfolding rate constant of I27, which was confirmed by molecular dynamics simulations. Our study reveals different effects that diverse osmolytes have on the mechanical properties of the protein, and suggests the potential use of osmolytes in modulating the mechanical stability of proteins required for various nano-biotechnological applications. � 2023 Elsevier B.V.Item Metal- and Hazardous Reagent-Free Transamidation Process: the NH2OH?HCl Promoted N-Formylation and N-Acylation Reaction under Solvent-Less Conditions(Taylor and Francis Ltd., 2023-09-14T00:00:00) Devi, Elangbam Pinky; Kant, Kamal; Kaldhi, Dhananjaya; Ghanta, Susanta; Sengupta, Ragini; Al-Zaqri, Nabil; Singh, Virender; Malakar, Chandi C.An efficient transamidation process has been described under solvent-less conditions. The transformation has been accomplished by employing NH2OH?HCl as a reagent and amines as substrates. The developed method is achieved in the absence of metals and hazardous reagents. A series of amines were explored to obtain the N-formylation and N-acylation reactions with excellent yields (81-96%) of products. The DFT analysis was also performed, which provides a clear understanding of the described N-formylation process. The postulated mechanism is well supported by the control experiments. � 2023 Taylor & Francis Group, LLC.Item Bifunctional electrochemical OER and HER activity of Ta2O5 nanoparticles over Fe2O3 nanoparticles(Royal Society of Chemistry, 2023-08-23T00:00:00) Ahmed, Imtiaz; Burman, Vishal; Biswas, Rathindranath; Roy, Ayan; Sharma, Rohit; Haldar, Krishna KantaHydrogen production via electrocatalytic water splitting offers encouraging innovations for sustainable and clean energy production as an alternative to conventional energy sources. The improvement of extraordinarily dynamic electrocatalysts is of great interest for work on the performance of gas generation, which is firmly blocked due to the sluggish kinetics of the oxygen evolution reaction (OER). The development of highly efficient base metal catalysts for electrochemical hydrogen and oxygen evolution reactions (HER and OER) is a challenging and promising task. In the present work, a particle over particles of Fe2O3 and Ta2O5 was successfully produced by hydrothermal treatment. The prepared composite shows promising catalytic performance when used as an electrochemical catalyst for OER and HER in alkaline and acidic electrolytes with low overpotentials of 231 and 201 mV at 10 mV cm?2, small Tafel slopes of 71 and 135 mV dec?1, respectively, and good stability properties. The calculated electrochemical surface area (ECSA) for composites is five times higher than that of the original oxides. The result of the OER is significantly better than that of commercial IrO2 catalysts and offers a promising direction for the development of water-splitting catalysts. � 2023 The Royal Society of Chemistry.Item 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, SandeepCotton 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.Item Design, synthesis, and unraveling the antibacterial and antibiofilm potential of 2-azidobenzothiazoles: insights from a comprehensive in vitro study(Frontiers Media SA, 2023-09-07T00:00:00) Qadir, Tanzeela; Kanth, Saadat A.; Aasif, Mohammad; Fadul, Abdalla N.; Yatoo, Gulam N.; Jangid, Kailash; Mir, Mushtaq A.; Shah, Wajahat A.; Sharma, Praveen K.The present study reports the synthesis of 2-azidobenzothiazoles from substituted 2-aminobenzothiazoles using sodium nitrite and sodium azide under mild conditions. All the synthesized compounds were examined for their antibacterial activity against Gram (+) bacteria, Staphylococcus aureus (ATCC 25923), Enterococcus faecalis (ATCC 51299), Bacillus cereus (ATCC 10876) and Gram (?) bacteria, Escherichia coli (ATCC 10536), Pseudomonas aeruginosa (ATCC 10145), Klebsiella pneumonia (ATCC BAA-2146)and clinical isolates of Gram (+) Methicillin Resistant S. aureus (MRSA) and Multi Drug Resistant E. coli. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values by broth dilution method revealed that compound 2d exhibited significant antibacterial potential against E. faecalis and S. aureus with MIC of 8�?g/mL, while other synthesized compounds had only moderate effects against all the tested species. The compound significantly inhibited the biofilm formation of the bacterial strains below its MIC. The selective cytotoxicity of Compound 2d towards bacterial cells was evidenced on extended exposure of Human Embryonic Kidney-293 cell line to higher concentrations of the compound. Hence, the present study confirmed that compound 2d can be a potential drug candidate for future development as an antibacterial drug. Copyright � 2023 Qadir, Kanth, Aasif, Fadul, Yatoo, Jangid, Mir, Shah and Sharma.Item Electrochemical Biosensors for the Detection of Antibiotics in Milk: Recent Trends and Future Perspectives(Multidisciplinary Digital Publishing Institute (MDPI), 2023-09-01T00:00:00) Singh, Baljit; Bhat, Abhijnan; Dutta, Lesa; Pati, Kumari Riya; Korpan, Yaroslav; Dahiya, IshaAntibiotics have emerged as ground-breaking medications for the treatment of infectious diseases, but due to the excessive use of antibiotics, some drugs have developed resistance to microorganisms. Because of their structural complexity, most antibiotics are excreted unchanged, polluting the water, soil, and natural resources. Additionally, food items are being polluted through the widespread use of antibiotics in animal feed. The normal concentrations of antibiotics in environmental samples typically vary from ng to g/L. Antibiotic residues in excess of these values can pose major risks the development of illnesses and infections/diseases. According to estimates, 300 million people will die prematurely in the next three decades (by 2050), and the WHO has proclaimed �antibiotic resistance� to be a severe economic and sociological hazard to public health. Several antibiotics have been recognised as possible environmental pollutants (EMA) and their detection in various matrices such as food, milk, and environmental samples is being investigated. Currently, chromatographic techniques coupled with different detectors (e.g., HPLC, LC-MS) are typically used for antibiotic analysis. Other screening methods include optical methods, ELISA, electrophoresis, biosensors, etc. To minimise the problems associated with antibiotics (i.e., the development of AMR) and the currently available analytical methods, electrochemical platforms have been investigated, and can provide a cost-effective, rapid and portable alternative. Despite the significant progress in this field, further developments are necessary to advance electrochemical sensors, e.g., through the use of multi-functional nanomaterials and advanced (bio)materials to ensure efficient detection, sensitivity, portability, and reliability. This review summarises the use of electrochemical biosensors for the detection of antibiotics in milk/milk products and presents a brief introduction to antibiotics and AMR followed by developments in the field of electrochemical biosensors based on (i) immunosensor, (ii) aptamer (iii) MIP, (iv) enzyme, (v) whole-cell and (vi) direct electrochemical approaches. The role of nanomaterials and sensor fabrication is discussed wherever necessary. Finally, the review discusses the challenges encountered and future perspectives. This review can serve as an insightful source of information, enhancing the awareness of the role of electrochemical biosensors in providing information for the preservation of the health of the public, of animals, and of our environment, globally. � 2023 by the authors.Item Determinants for macromolecular crowding-induced thermodynamic stabilization of acid-denatured cytochrome c to molten globules(Elsevier B.V., 2023-07-22T00:00:00) Kumari, Beeta; Shabnam; Yadav, Manisha; Kumar, Manoj; Kushwaha, Pratibha; Prakash Prabhu, N.; Kumar, RajeshThe macromolecular crowding effect transforms the acid-denatured ferricytochrome c (cyt cIII) (UA-state) to molten-globule (MGMC-state) at pH 1.85. Crowding-induced stabilization free energy (??G) and preferential hydration ??W were estimated for the UA ? MGMC transition. The magnitudes of ??G and ??W were found to be decreased as dextran 70 (D70) > dextran 40 (D40) > ficoll 70 (F70), which demonstrates that ??G and ??W track the molecular size and shape of the crowder towards refolding and stabilization of UA-state to MGMC-state. Analysis of effects of crowders (D40, D70, F70) on thermal and chemical-denaturations of acid-denatured cyt cIII provided several important information, (i) macromolecular crowding increased the thermodynamic stability of acid-denatured cyt cIII, (ii) concentration, size and shape of crowder control the crowding-induced thermodynamic stabilization of MGMC-state, (iii) crowding effect increased the thermal-denaturation midpoint (Tm) with a slight change in enthalpy (?Hm), suggesting that the steric-excluded volume effect contributes to the crowding-induced increased thermal stability of the acid-denatured protein. Analysis of entropy ? enthalpy plots for D40, D70, and F70 reveals that in addition to the steric-excluded volume effect, the enthalpic contribution is also added to the macromolecular crowding-induced stabilization of acid-denatured cyt cIII. The dilute-medium, compound-crowder, purely entropic-crowder and purely enthalpic-crowder curves were obtained for acid-denatured cyt cIII for D70, D40 and F70. The crossover temperature, Tx was calculated from the dilute and compound-crowder curves. The Tx values measured for D40, D70, and F70 were found to be ? 250.15 K, 272.15 K, and 275.15 K, respectively, which suggests that the Tx value depends on the size and shape of the crowder. Furthermore, the observation of a lower value of Tx and a minor enthalpic component for D40, D70, and F70 is likely due to the formation of weaker soft interactions of acid-denatured cyt cIII with D40, D70, and F70. � 2023 Elsevier B.V.Item DABCO Mediated Sulfur Activation-Intramolecular De-Nitration Strategy for the Synthesis of Novel Dihydrothiochromeno[4,3-c]pyrazoles(John Wiley and Sons Inc, 2023-07-24T00:00:00) Deepika; Paul, Avijit K.; Malakar, Chandi C.; Bansal, Ajay; Singh, VirenderA facile and highly efficient metal-free approach has been unfolded for the synthesis of novel dihydrothiochromeno[4,3-c]pyrazoles using elemental sulfur as a powerful sulfurating reagent. This method includes sp2 C?H functionalization followed by sp2 C?NO2 group displacement using elemental sulfur as an odourless sulfur source activated by DABCO in DMSO. Using the developed synthetic strategy, a library of 29 novel dihydrothiochromeno[4,3-c]pyrazoles, incorporating two pharmacologically important scaffolds has been synthesized in 52�76% yield with a broad substrate scope. A sensible mechanistic proposal has been projected based on control experiments. � 2023 Wiley-VCH GmbH.Item Porous nanorods by stacked NiO nanoparticulate exhibiting corn-like structure for sustainable environmental and energy applications(Royal Society of Chemistry, 2023-07-20T00:00:00) Manjunath, Vishesh; Bimli, Santosh; Singh, Diwakar; Biswas, Rathindranath; Didwal, Pravin N.; Haldar, Krishna Kanta; Deshpande, Nishad G.; Bhobe, Preeti A.; Devan, Rupesh S.A porous 1D nanostructure provides much shorter electron transport pathways, thereby helping to improve the life cycle of the device and overcome poor ionic and electronic conductivity, interfacial impedance between electrode-electrolyte interface, and low volumetric energy density. In view of this, we report on the feasibility of 1D porous NiO nanorods comprising interlocked NiO nanoparticles as an active electrode for capturing greenhouse CO2, effective supercapacitors, and efficient electrocatalytic water-splitting applications. The nanorods with a size less than 100 nm were formed by stacking cubic crystalline NiO nanoparticles with dimensions less than 10 nm, providing the necessary porosity. The existence of Ni2+ and its octahedral coordination with O2? is corroborated by XPS and EXAFS. The SAXS profile and BET analysis showed 84.731 m2 g?1 surface area for the porous NiO nanorods. The NiO nanorods provided significant surface-area and the active-surface-sites thus yielded a CO2 uptake of 63 mmol g?1 at 273 K via physisorption, a specific-capacitance (CS) of 368 F g?1, along with a retention of 76.84% after 2500 cycles, and worthy electrocatalytic water splitting with an overpotential of 345 and 441 mV for HER and OER activities, respectively. Therefore, the porous 1D NiO as an active electrode shows multifunctionality toward sustainable environmental and energy applications. � 2023 The Royal Society of Chemistry.Item Bio-assisted Synthesis of Au/Rh Nanostructure Electrocatalysts for Hydrogen Evolution and Methanol Oxidation Reactions: Composition Matters!(American Chemical Society, 2023-08-11T00:00:00) Biswas, Rathindranath; Dastider, Saptarshi Ghosh; Ahmed, Imtiaz; Biswas, Sayani; Mondal, Krishnakanta; Haldar, Krishna KantaIn the field of catalysis, bimetallic nanostructures have attracted much interest. Here, we discuss the effect of Au/Rh bimetallic composition-tuned nanostructure and electrocatalytic activity. A simple bio-assisted technique was used to fabricate multiple Au:Rh nanoplate ratios (25:75, 50:50, and 75:25). XRD and XPS studies show that both Au and Rh phases coexist in a bimetallic nanostructure, and electron microscopy confirms the formation of a triangle-shaped nanoplate. Au0.25Rh0.75 exhibited the maximum catalytic activity and good stability for hydrogen evolution reaction (HER) with an overpotential of 105 mV at a current density of 10 mA/cm2. On the other hand, Au0.50Rh0.50 exhibits a higher activity for methanol oxidation reaction (MOR) compared to the other compositions. Theoretical studies indicate that the electrocatalytic enhancement obtained for both HER and MOR relies on electronic modification effects of the surface, with the overall reaction energy profile being optimized due to Au/Rh d-band mixing. � 2023 American Chemical Society.Item Transition-Metal-Free Cascade C-N Bond Formation: An Effective Strategy for the Synthesis of ?-Carboline N-Fused Imidazolium Acetates and Estimation of their Light-Emitting Properties(Georg Thieme Verlag, 2023-08-08T00:00:00) Singh, Manpreet; Vaishali, Vaishali; Deepika, Deepika; Jyoti, Jyoti; Sharma, Shubham; Banyal, Naveen; Kumar, Prashant; Budhalakoti, Bharti; Malakar, Chandi C.; Singh, VirenderA simple, efficient, and practical metal-free protocol has been devised to synthesize imidazopyrido[3,4-b]indole-based fluorophores decorated with carbazole/ F-carboline/pyridine scaffolds via three consecutive C.N bond formations in a single operation. A wide range of aromatic amines (2-aminopyridines, 3-aminocarbazole, and anilines) were successfully applied to synthesize the complex imidazolium ions. The significant features of this strategy include high efficiency, mild and environmentally benign reaction conditions, no chromatographic purification, and broad substrate scope with excellent yields of the isolated products. Moreover, excellent photophysical properties (up to 85%) were exhibited by these fluorophores. � 2022 Georg Thieme Verlag. All rights reserved.Item Visible-Light-Induced Metal- and Photocatalyst-Free Radical Cascade Cyclization of Cinnamamides for Synthesis of Functionalized Dihydroquinolinones(American Chemical Society, 2023-07-18T00:00:00) Nishad, Chandra Shekhar; Suman, Pallav; Saha, Himadri; Banerjee, BiplabVisible-light-promoted metal- and photocatalyst-free radical cascade cyclization of cinnamamides with ?-oxocarboxylic acids is described for sustainable synthesis of diverse pharmaceutically important dihydroquinolinone scaffolds in one pot under mild conditions. The decarboxylative cascade cyclization proceeded efficiently at room temperature without the need for expensive photocatalysts such as Ir or Ru complexes, which indicates the practicability and environmentally benign nature of this protocol. Preliminary mechanistic studies reveal that the blue LED irradiation efficiently cleaves the I-O bond of the hypervalent iodine reagent PhI(O2CCOAr)2 formed through ligand exchange between iodobenzene diacetate and arylglyoxylic acid to initiate the cascade reaction. The synthetic value of this operationally simple and energy-efficient method is further demonstrated by late-stage functionalization of drug molecules in excellent yields. � 2023 American Chemical Society.Item Copper catalysed regioselective synthesis of pyrimidine substituted Indolizino[8,7-b]indole derivatives via cascade A3 annulation(Elsevier Ltd, 2023-07-08T00:00:00) Kumar, Sunit; Kumar, Rakesh; Malakar, Chandi C.; Singh, VirenderCu(II) salt has been found to be an efficient catalyst for the regioselective synthesis of a series of novel indolizino [8,7-b]indole derivatives with pyrimidine tethers via three-component annulation of 1-formyl-9H-?-carbolines (Kumujian C), 2-amino-pyrimidines and terminal alkynes. The reactions proceeds through Cu-catalysed A3-coupling followed by intramolecular cyclisation in a cascade manner. The scope of strategy has been exemplified with a library of biologically interesting 25 indolizino [8,7-b]indoles with pyrimidine tethers which mimics several natural products. � 2023 Elsevier LtdItem BiFeO3/g-C3N4/f-CNF ternary nanocomposite as an efficient photocatalyst for methylene blue dye degradation under solar light irradiation(Elsevier Ltd, 2023-06-21T00:00:00) Deeksha; Kour, Pawanpreet; Ahmed, Imtiaz; Haldar, Krishna Kanta; Yadav, C.S.; Sharma, Surender Kumar; Yadav, KamleshThe development of Perovskite oxide photocatalysts with superior dye degradation efficiency under solar light irradiation has gained attention in recent years, owing to their extraordinary flexibility, chemical composition, and tunability. Herein, we report the facile synthesis of a novel ternary composite composed of BiFeO3 (BFO) perovskite, g-C3N4, and functionalized carbon nanofibers (f-CNF), referred to as BFO/g-C3N4/f-CNF using a simple solution method as a photocatalyst to accelerate the degradation of methylene blue dye. Detailed structural and microstructural features confirm the formation of a ternary composite composed of BFO nanoparticles and f-CNFs mounted on g-C3N4 nanosheets. The photocatalytic activity of the sample for the degradation of methylene blue dye was studied in solar light using UV�visible spectroscopy. The BFO/g-C3N4/f-CNF ternary composite displays excellent photocatalytic activity with a degradation rate of 87 % after illumination for 120 min under solar light than BFO, g-C3N4, and binary composites BFO/g-C3N4 and BFO/f-CNF. The highest rate constant (k = 0.01675 min?1) for BFO/g-C3N4/f-CNF further confirms improved photocatalytic efficiency. The red shift in the UV�visible absorption spectrum of BFO/g-C3N4/f-CNF indicates a reduced band gap (1.9 eV) compared to that of pure BFO (2.28 eV) and g-C3N4 ( 2.72 eV). A decrease in the photoluminescence intensity of the ternary composite compared to that of BFO indicates the inhibition of photoexcited electron recombination which results in the availability of more charge carriers for the photocatalytic process. The enhanced efficiency of BFO/g-C3N4/f-CNF can be explained by the synergistic effect between BFO and g-C3N4 and the incorporation of f-CNF further promotes the migration rate of electrons from BFO to g-C3N4. � 2023 Elsevier B.V.Item Europium Molybdate/Molybdenum Disulfide Nanostructures with Efficient Electrocatalytic Activity for the Hydrogen Evolution Reaction(American Chemical Society, 2023-04-26T00:00:00) Ghosh, Debarati; Ghosal Chowdhury, Monojit; Biswas, Rathindranath; Haldar, Krishna Kanta; Patra, AmitavaThe design of hybrid nanostructures of molybdenum disulfide (MoS2) has been extensively explored as potent electrocatalysts for hydrogen generation reactions. Here, we report the in situ synthesis of a nanocomposite containing europium molybdate [Eu2(MoO4)3] and molybdenum disulfide (MoS2) for an enhanced electrochemical hydrogen evolution reaction (HER). The characteristic X-ray diffraction (XRD) peaks of both 2H-MoS2 and ?-Eu2(MoO4)3 confirm the formation of the nanocomposite. The nanoflower (NF) architecture of MoS2 coupled with flakes of europium molybdate is observed in the transmission electron microscopy (TEM) and scanning electron microscopy (SEM) images, which lead to an enhanced surface area of the nanocomposite. Raman and X-ray photoelectron spectroscopy (XPS) studies reveal a variation in the layer thickness of MoS2 and a significant interfacial electronic interaction between Eu2(MoO4)3 and MoS2. As evident from the small onset potential of ?0.05 V vs reversible hydrogen electrode (RHE) and a lower overpotential value of 186 mV (at a current density of 10 mA/cm2), the nanocomposite outperforms pristine MoS2 nanoflowers in terms of electrocatalytic HER. The charge-transfer resistance of the nanocomposite (80.02 ?) is significantly low compared to pristine MoS2 (158.37 ?), thus confirming the enhanced interfacial charge transfer. The Tafel slope value of the nanocomposite (189 mV/dec) is notably less than that of pristine MoS2 (313 mV/dec), indicating the enhanced HER activity of the nanocomposite. The fabrication of lanthanide-containing MoS2 nanocomposites appears to be promising for an efficient electrocatalytic activity for the hydrogen evolution reaction. � 2023 American Chemical Society