School Of Basic And Applied Sciences

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Subject: search.filters.subject.Sulfur compounds

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    Simple and Productive Method to Develop Highly Sensitive and Fast Infrared Photodetector Using Spray Deposited Nanocrystalline PbS Thin Film
    (Institute of Physics, 2023-02-16T00:00:00) Thabit, Mohammed Y. H.; Kaawash, Nabeel M. S.; Begum, Sumayya; Halge, Devidas I.; Narwade, Vijaykiran N.; Alegaonkar, Prashant S.; Bogle, Kashinath A.
    This work demonstrates the development of a highly sensitive and fast infrared photodetector using a PbS thin film deposited using a simple and scalable method known as "spray pyrolysis". An aqueous precursor solution was deposited on a glass substrate at 150 �C have a cubic phase of PbS. Silver electrodes with a 1 mm gap are drawn on the film to create photo-detector devices. Low resistive contact between the silver electrode and the PbS film is revealed from the linear I-V measurements performed in the dark and under light illumination. Under the illumination of a 100-watt tungsten lamp, the photo-responsivity, sensitivity, response time, and decay time of the PbS film were measured. The Ag/PbS/Ag photodetector device has a responsivity of 70 mA/W, a sensitivity of 200 at 30 V, and the best response and decay times of 6.4 and 15.6 ms, respectively. The photodetector device produced by this simple and low-cost fabrication method has a fast response and decay time. � Published under licence by IOP Publishing Ltd.
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    Gaussian field-based 3D-QSAR and molecular simulation studies to design potent pyrimidine-sulfonamide hybrids as selective BRAFV600E inhibitors
    (Royal Society of Chemistry, 2022-10-21T00:00:00) Singh, Ankit Kumar; Novak, Jurica; Kumar, Adarsh; Singh, Harshwardhan; Thareja, Suresh; Pathak, Prateek; Grishina, Maria; Verma, Amita; Yadav, Jagat Pal; Khalilullah, Habibullah; Pathania, Vikas; Nandanwar, Hemraj; Jaremko, Mariusz; Emwas, Abdul-Hamid; Kumar, Pradeep
    The �RAS-RAF-MEK-ERK� pathway is an important signaling pathway in melanoma. BRAFV600E (70-90%) is the most common mutation in this pathway. BRAF inhibitors have four types of conformers: type I (?C-IN/DFG-IN), type II (?C-IN/DFG-OUT), type I1/2 (?C-OUT/DFG-IN), and type I/II (?C-OUT/DFG-OUT). First- and second-generation BRAF inhibitors show resistance to BRAFV600E and are ineffective against malignancies induced by dimer BRAF mutants causing �paradoxical� activation. In the present study, we performed molecular modeling of pyrimidine-sulfonamide hybrids inhibitors using 3D-QSAR, molecular docking, and molecular dynamics simulations. Previous reports reveal the importance of pyrimidine and sulfonamide moieties in the development of BRAFV600E inhibitors. Analysis of 3D-QSAR models provided novel pyrimidine sulfonamide hybrid BRAFV600E inhibitors. The designed compounds share similarities with several structural moieties present in first- and second-generation BRAF inhibitors. A total library of 88 designed compounds was generated and molecular docking studies were performed with them. Four molecules (T109, T183, T160, and T126) were identified as hits and selected for detailed studies. Molecular dynamics simulations were performed at 900 ns and binding was calculated. Based on molecular docking and simulation studies, it was found that the designed compounds have better interactions with the core active site [the nucleotide (ADP or ATP) binding site, DFG motif, and the phospho-acceptor site (activation segment) of BRAFV600E protein than previous inhibitors. Similar to the FDA-approved BRAFV600E inhibitors the developed compounds have [?C-OUT/DFG-IN] conformation. Compounds T126, T160 and T183 interacted with DIF (Leu505), making them potentially useful against BRAFV600E resistance and malignancies induced by dimer BRAF mutants. The synthesis and biological evaluation of the designed molecules is in progress, which may lead to some potent BRAFV600E selective inhibitors. � 2022 The Royal Society of Chemistry.
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    Coupling Nonstoichiometric Zn0.76Co0.24S with NiCo2S4Composite Nanoflowers for Efficient Synergistic Electrocatalytic Oxygen and Hydrogen Evolution Reactions
    (American Chemical Society, 2022-12-15T00:00:00) Biswas, Rathindranath; Thakur, Pooja; Ahmed, Imtiaz; Rom, Tanmay; Ali, Mir Sahidul; Patil, Ranjit A.; Kumar, Bhupender; Som, Shubham; Chopra, Deepak; Paul, Avijit Kumar; Ma, Yuan-Ron; Haldar, Krishna Kanta
    Transition-metal sulfide-based composite nanomaterials have garnered extensive interest not only for their unique morphological architectures but also for exploring as a noble-metal-free cost-effective, durable, and highly stable catalyst for electrochemical water splitting. In this work, we synthesized in situ nonstoichiometric Zn0.76Co0.24S with NiCo2S4binary composite flowers (Zn0.76Co0.24S/NiCo2S4) in one step by thermal decomposition of Zn2[PDTC]4and Ni[PDTC]2complexes by a solvothermal process in a nonaqueous medium from their molecular precursor, and their potential application in electrochemical oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) was investigated. Field-emission scanning electron microscopy and transmission electron microscopy analyses revealed the flower-shaped morphology of as-synthesized Zn0.76Co0.24S/NiCo2S4. Again, the structural and chemical compositions were confirmed through powder X-ray diffraction and X-ray photoelectron spectroscopy studies, respectively. The as-obtained 3D flower-type Zn0.76Co0.24S/NiCo2S4nanostructure was further subject to electrochemical OER and HER in alkaline and acidic media, respectively. Zn0.76Co0.24S/NiCo2S4showed low overpotential values of 248 mV (Tafel slope, 85 mV dec-1) and 141 mV (Tafel slope, 79 mV dec-1) for OER and HER activities, respectively, due to the synergistic effects of Zn0.76Co0.24S and NiCo2S4. Several long-term stability tests also affirmed that the Zn0.76Co0.24S/NiCo2S4composite nanostructure is a highly stable and efficient electrocatalyst toward OER and HER activities as compared to the recently reported superior bifunctional electrocatalysts as well as state-of-the-art materials. � 2023 American Chemical Society. All rights reserved.
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    Metal-Free Direct Access to N-Sulfonyl Amidines from Sulfonamides and Secondary Amines Involving Tandem C-N Bond Formations
    (American Chemical Society, 2022-08-17T00:00:00) Nishad, Chandra Shekhar; Haldar, Krishna Kanta; Banerjee, Biplab
    We report a mild and efficient metal-free one-pot procedure for the synthesis of N-sulfonyl amidines via the direct reaction of sulfonamides with secondary amines without using any additives. A wide range of substrates with variety of functional groups is well tolerated under the reaction conditions. Preliminary mechanistic studies indicate that the secondary amine plays a dual role as a C1 source of the amidine group and an aminating agent. Synthetic utility of this method is shown in the late-stage functionalization of drug molecules on the gram scale. � 2022 American Chemical Society.
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    Interfacial Engineering of CuCo2S4/g-C3N4Hybrid Nanorods for Efficient Oxygen Evolution Reaction
    (American Chemical Society, 2021-07-29T00:00:00) Biswas, Rathindranath; Thakur, Pooja; Kaur, Gagandeep; Som, Shubham; Saha, Monochura; Jhajhria, Vandna; Singh, Harjinder; Ahmed, Imtiaz; Banerjee, Biplab; Chopra, Deepak; Sen, Tapasi; Haldar, Krishna Kanta
    Altering the morphology of electrochemically active nanostructured materials could fundamentally influence their subsequent catalytic as well as oxygen evolution reaction (OER) performance. Enhanced OER activity for mixed-metal spinel-type sulfide (CuCo2S4) nanorods is generally done by blending the material that has high conductive supports together with those having a high surface volume ratio, for example, graphitic carbon nitrides (g-C3N4). Here, we report a noble-metal-free CuCo2S4 nanorod-based electrocatalyst appropriate for basic OER and neutral media, through a simple one-step thermal decomposition approach from its molecular precursors pyrrolidine dithiocarbamate-copper(II), Cu[PDTC]2, and pyrrolidine dithiocarbamate-cobalt(II), Co[PDTC]2 complexes. Transmission electron microscopy (TEM) images as well as X-ray diffraction (XRD) patterns suggest that as-synthesized CuCo2S4 nanorods are highly crystalline in nature and are connected on the g-C3N4 support. Attenuated total reflectance-Fourier-transform infrared (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy studies affirm the successful formation of bonds that bridge (Co-N/S-C) at the interface of CuCo2S4 nanorods and g-C3N4. The kinetics of the reaction are expedited, as these bridging bonds function as an electron transport chain, empowering OER electrocatalytically under a low overpotential (242 mV) of a current density at 10 mA cm-2 under basic conditions, resulting in very high durability. Moreover, CuCo2S4/g-C3N4 composite nanorods exhibit a high catalytic activity of OER under a neutral medium at an overpotential of 406 mV and a current density of 10 mA cm-2. � 2021 American Chemical Society.