Browsing by Author "Singh, Vijay"

Now showing 1 - 13 of 13
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    A combined theoretical and experimental study of nickel derivative [Daiquiris(nicotinamide-jN1)nickel (II)]-lfumarato-K2O1:O4
    (World Scientific Pub Co Pte Ltd, 2023) Pandey, Anoop Kumar; Chand, Satish; Diwedi, Apoorva; Singh, Vijay; Singh, Vinod Kumar; Mishra, Vijay Narayan
    The ground state geometry of the nickel derivative [Daiquiris(nicotinamide-jN1) nickel(II)]-fumarato-K2O1:O4 has been optimized and is being led toward its quantum chemical analysis in this paper. For more accuracy, we used the 6-311[Formula: see text]G (d, p) basis set for C, H, N, and O atoms and the LAN2DZ basis set for Ni. The calculated and experimental infrared (IR) spectra for the title molecule are well correlated, and the correlation factor [Formula: see text] shows that the method effectively interprets the molecule’s IR spectra. The electronic properties such as highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies and associated energy gap have been calculated by Time-Dependent Density Functional Theory (TD-DFT) approach. The natural bond orbital (NBO) analysis of the molecule describes how interatomic charge transfer results in the formation of bonding–nonbonding interactions. The experimental and calculated Ultraviolet visible (UV-Vis) spectra are compared. We anticipate our work will inspire fresh approaches to the title molecule’s ongoing research.
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    Biological, electronic, NLO, NBO, TDDFT and vibrational analysis of 1-benzyl-4-formyl-1H-pyrrole-3-carboxamide
    (Iranian Research & Development Center for Chemical Industries, 2018) Pandey, Anoop Kumar; Mishra, Vijay Narayan; Singh, Vijay
    Biological Electronic, Optical Properties, and Vibrational Analysis of 1-benzyl-4-formyl-1H-pyrrole 3carboxamide are studied by using a combination of DFT/B3LYP method and 6-311G (d, p) basis set. Optimized parameters of the title molecule are well-matched with the experiments. The NLO properties of 1-benzyl-4-formyl-1H-pyrrole 3carboxamide have been examined with the help of Polarizability and Hyper-Polarizability. The electronic properties of 1-benzyl-4-formyl-1H-pyrrole 3carboxamide are described with the help of HOMO, LUMO composition. The UV spectra suggest that a strong excitation line occurs at 2.03 eV (160 nm) due to H-2→LUMO (30%). NBO analysis shows that hyper conjugative interaction energy has higher value during LP→ π*, π→ π* transitions. Several biological activities are calculated by PASS software. Docking of the molecule is performed with 5P4Q protein and FF score is -1051.65A.U.
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    Comparative study of molecular docking, structural, electronic, and fukui function studies on favipiravir and its newly designed derivatives (potential inhibitors) for COVID-19 protease
    (Wiley Online Library, 2023) Pandey, Anoop Kumar; Singh, Vijay; Dwivedi, Apoorva
    Favipiravir is an comparative molecular docking currently being trialed as a COVID-19 treatment. These results motivate us to develop new species (possibly drugs) from favipiravir, perform comparative molecular docking, and re-examine their biological and pharmacological activities. Detailed quantum chemical research on favipiravir and its newly designed derivatives has been carried out with the help of DFT/B3LYP/6–311 + + G (d, p). In the present work, the structure of favipiravir has been modified and 12 new species have been modeled (all species are inherently stable because no virtual frequency is found during the vibration analysis). Reactivity of all species using various descriptors (local) such as Fukui function, local softness, electrophilicity, and global, i.e., electronegativity, hardness, HOMO–LUMO gap, etc. of the same are calculated and discussed. In silico studies such as molecular docking of all species and complete quantum chemistry studies suggest that four of them may mitigate the effects of the COVID-19 protease.
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    Computational study of adsorption effects of Karanjin drug over carbon Nanotube (C56H16) as factor of drug delivery system: a quantum chemical approach
    (World Scientific, 2021) Pandey, Anoop Kumar; Singh, Vijay; Dwivedi, Apoorva
    Karanjin, phytochemical from Pongamia pinnata is reported to be effective against HIV that causes AIDS in humans, however, the delivery of this therapeutic molecule still needs improvement. Hence, this study provides a better understanding of the nonbonded interaction between an anti-HIV drug karanjin and carbon nanotube (CNT) (C56H16). The electronic structure and interaction properties of the molecule karanjin over the surface of CNT were theoretically studied in the gas phase by DFT/B3LYP/6-31G (d,pd,p) level of theory for the first time. The UV–Vis spectra and transitions of the karanjin drug, CNT (C56H16) and complex CNT (C-56)/karanjin in gas phase have been calculated by time-dependent density functional theory (TDDFT) for the investigation of adsorption effect. To support our hypothesis, we have performed quantum chemical analysis for CNT (C56H16)/karanjin in water and DMSO solvent. In this process, this CNT (C-56)/karanjin complex enters into affected cell in liquid medium. After that, the drug delivery system CNT (C-56) unloads karanjin at the affected site. The binding character interactive species have been determined by NBO and AIM analysis. The frontier orbital HOMO–LUMO gap, chemical softness, chemical hardness have also been calculated to understand its complete chemical properties. The outcomes from our interaction of drug karanjin with CNT (C56H16) will be instrumental for better drug delivery potential in the upcoming future.
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    Exploration of superhalogen nature of Pt(CN)n complexes (n = 1–6) and their abilities to form supersalts and superacids: a DFT–D3 study
    (Springer, 2021) Rasheed, Tabish; Siddiqui, Shamoon Ahmad; Kargeti, Ankit; Shukla, Dharmesh Vikram; Singh, Vijay; Pandey, Anoop Kumar
    Unique superhalogen properties of Pt(CN)n complexes (n = 1–6) have been investigated under the quantum chemical formalism. The study involves theoretical calculations for both neutral and anionic forms of Pt(CN)n using density functional theory (DFT) with the hybrid functional B3LYP. In order to improve the accuracy of calculations, 6–311+G(d) basis set was implemented for CN moieties, whereas SDD basis set supplemented with Stuttgart/Dresden relativistic effective core potential was used for Pt atom. Long-range electron correlations in the subject molecules have been accounted for by using Grimme’s dispersion with the D3 damping function. HOMO-LUMO energy band gaps, vibrational frequencies, and dissociation energies of Pt(CN)n complexes have been calculated to investigate their relative stability as well as reactivity. Salt-forming capability of Pt(CN)n complexes has also been analyzed. Reliable low-cost investigations on superacidity properties of associated protonated species have been carried out keeping their industrial applications in mind.
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    Frequency response and power dissipation of RC coupled CE amplifier by using series and parallel network of like transistors
    (Wiley Online Library, 2023) Tiwari, Satyendra Nath; Khadarabad, Ghouse Mohiuddin; Pandey, Anoop Kumar; Dwivedi, Apoorva; Pandey, Shri Prakash; Singh, Vijay
    The RC-coupled small-signal amplifier is a widely used circuit that serves as a basic building block in electronic circuits. The study of amplifier circuits with various component modifications may yield important results that can be utilized to improve circuit designs based on application needs. Using the Pspice 9.5.2 simulation tool, a study of a BJT-based CE amplifier is carried out to determine the dependence of frequency response, bandwidth, maximum voltage gain, power dissipation, input impedance, and other parameters while using a network of BJTs coupled in parallel and in series from Q1 to Qn.
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    Protonated MF– (M=Au, Ir, Os, Re, Ta, W) behave as superacids and are building blocks of new class of salt
    (Springer, 2021) Pandey, Anoop Kumar; Shukla, D. V.; Narayan, Vijay; Singh, Vijay; Dwivedi, Apoorva
    Novel strong superacids HMF6 (M=Au, Ir, Os, Re, Ta, W) are proposed and are investigated with the help of DFT/B3LYP method and SDD basis set for 5d transition metals as well as 6-311++G (d) basis set for H and F atoms. These HMF6 superacids are composed with Brønsted/Lewis (MF5/HF). The stabilities of HMF6 are discussed with the help of structure, dissociation energy through HF channel, and normal mode analysis. The ΔEdisso>0 shows that all HMF6 superacids are energetically stable through HF dissociation channel. The gas phase acidity of HMF6 has been calculated by the Gibbs free deprotonation energy. All species of HMF6 belong to superacids having smaller deprotonation energy; 100% concentrated H2SO4 acids however predicted ΔGdep of HAuF6, is nearly equal to ΔGdep of HSbF6. The strength of acidity of HMF6 is closely related to vertical detachment energy (VDE) of their corresponding superhalogen anions MF−6MF6−. This study provide appropriate path to design new class of superacids which is more acidic than HSbF6. We have also modelled and discussed supersalt by the interaction of Li with MF6 superhalogen.
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    Quantum chemical calculations of a novel Specie–Boron Nano Bucket (B16) and the interaction of its complex (B15-Li) with drug Resorcinol
    (IOS Press, 2020) Pandey, Anoop Kumar; Singh, Vijay; Dwivedi, Apoorva
    At Nano-scale level, innovative biomedical techniques are developed in advanced drug delivery systems and targeted Nano-therapy. Ultrathin needles provide a low invasive and highly selective means for molecular delivery and cell manipulation. This article studies geometry and the stability of Boron Nano-Bucket (B16 Cluster of Bucket Shape) and B15-Li complex by using computational modelling methods. The equilibrium geometry of Boron Nano-Bucket and BNB-Li complex in the ground state have been determined and analyzed by Density functional theory (DFT) employing 6-311 G (d, p) as the basis set. The frontier orbital HOMO-LUMO gap, Chemical Softness, Chemical Hardness have also been calculated to understand its complete Chemical Properties. In this study, we have also performed BNB-Li complex interaction with drug Resorcinol. The binding character interactive species have been determined by NBO and AIM analysis. From these studies, we can say that BNB and BNB-Li complex may also potentially able to stabilize ions around their structure like Carbon Nano Niddle (CNN) in future. The polar characteristics of CNN and their ability to carry ionic species, Li doped Boron Nano-Bucket might be suitable to act as drug carrier through nonpolar biologic media.
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    Quantum chemical study of effect on adsorption properties of antituberculosis drug N-Cyclopentylidenepyridine-4-carbohydrazide interaction with CNT(C56H16)
    (Elsevier, 2023) Pandey, Anoop Kumar; Dwivedi, Apoorva; Mishra, Avinash Kumar; Tiwari, Satyendra Nath; Singh, Vijay; Vuai, Said A. H.
    Tuberculosis is the most common disease that affects the lungs in humans. The electronic structural and chemical properties of the antituberculosis drug N-Cyclopentylidenepyridine-4-carbohydrazide have already been investigated. The adsorption properties of the antituberculosis drug N-Cyclopentylidenepyridine-4-carbohydrazide (CPPC) with single-wall carbon nanotube CNT(C56H16) are investigated using a combination of DFT/B3LYP method and 6-31G(d,p) basis set in both gaseous and water solvent, and calculated results are compared. By comparing CNT's corresponding optimized bond lengths with CNT@CPPC, the effect of CPPC adsorption on optimized drug delivery system parameters has been discussed. Based on topological parameters, the nonbonding interaction between CNT and CPPC drug is discussed using QTAIM analysis at BCP in both gas and water solvent. The thermodynamical stability of the CPPC@CNT adsorption process is also calculated, showing the adsorption of CPPC with CNT favors in both media. Natural bond analysis (NBO) was used to investigate the IR spectra, and the effect of charge transfer from CPPC to CNT in CNT@CPPC in both media provides information about how polarity changes from gas to water solvent. Because drug delivery action is done in blood plasma, the UV–Vis spectra of CNT are compared to CNT@CPPC in water solvent, providing insight into the adsorption of CPPC drug by CNT. We have compared the chemical shift isotropic (CS1) and chemical shift anisotropic (CSA) of CNT, CPPC, and CNT@CPPC to determine the change in electron density.
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    Simulation study to enhance the efficiency of switching devices using the combinations of diodes in various networks
    (Wiley Online Library, 2023) Tiwari, Satyendra Nath; Khadarabad, Ghouse Mohiuddin; Pandey, Shri Prakash; Pandey, Anoop Kumar; Singh, Vijay
    In this communication, PSpice simulation software is used to design and characterize reverse biasing modes in series and parallel combinations. Using multiple diodes of similar types, how the breakdown voltage and power dissipation vary in parallel and series modes in reverse bias is investigated. In this paper, correlation equations and correlation factors between voltage and current in both series and parallel combinations using n = 1-5 diodes in reverse bias are also found. The second-order correlation equation between voltage and current provides a new way for designing new networks of PN junction diodes for better power gain. The mathematical formulation for applied voltage and average current of n = 1-10 diodes in parallel and series combinations is also calculated, which can help researchers to design new network circuits for switching devices in the electronics industry.
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    Stimulated Raman side and backscatter instabilities of crossed laser beams in plasma
    (Elsevier BV, 2023) Singh, Vijay; Mvile, Benatus Norbert; Pandey, Anoop Kumar
    Stimulated Raman scattering (SRS) instability due to two nonlinearly coupled laser beams propagating in homogeneous, thermal plasma is analyzed. The temporal evolution equations for pump, scattered and Langmuir waves excited due to the interaction are set up. Using numerical techniques temporal evolution of amplitudes of pump, scattered and resultant Langmuir waves for side and back SRS instabilities have been obtained in the non-relativistic regime. The temporal growth rate, saturation time and saturation amplitude of waves excited by two crossed (perpendicular) lasers are studied and compared with the single beam case. The model considers pump depletion to be the dominant saturation mechanism. The study points towards a new concept for generation of high amplitude Langmuir waves.
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    Time-Dependent Density Functional Theory, AIM Analysis, NLO, and Thermodynamic Properties of Propofol and Adsorption Effects of Propofol Drug over Carbon Nanotube (C56H16) as the Factor of Drug Delivery System
    (Wiley Online Library, 2023) Dwivedi, Apoorva; Narayan, Vijay; Singh, Vijay; Singh, Vinod Kumar; Pandey, Anoop Kumar
    This article presents a comprehensive quantum chemical study of the Propofol molecule using the Density Functional Theory (DFT). The UV (Ultra Violet) plots, Non-Linear Optical (NLO) properties' calculations, and Density of State (DOS) plots are studied with the help of DFT using 6–311G (d, p) as the basis set. Quantum Theory of Atoms in Molecules (QTAIM) analysis shows weak intramolecular interactions of CH…. O. The NLO calculations show that the molecule is a good candidate as a future nonlinear optical material. The parameters of NLO Propofol and Propofol (CH2) n, n = 1–5 are also calculated with the same level theory. During this study, we have mainly focused on the profile of its electronic properties, the vital vibrational modes during movement in the isolated gas phase, and a better understanding of the unbound interaction between drug propofol and carbon nanotubes [C56H16].
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    Variation in structural chemical reactivity and nonlinear optical (NLO) properties of C56H16 nanotube after endohedral doping of superalkali (Na2F) and superhalogen (BF4): A DFT Study
    (Springer Science and Business Media LLC, 2023) Singh, Vijay; Dwivedi, Apoorva; Mishra, Avinash Kumar; Singh, Vinod Kumar; Pandey, Anoop Kumar
    The carbon nanotube’s (C56H16) stability and drug delivery capacity have already been investigated. The interaction of carbon nanotube C56H16 with superhalogen BF4 and superakali Na2F is studied using density functional theory (DFT), which resulted in the formation of the Na2F-CNT@BF4 endohedral complex. QTAIM analysis is used to calculate the nonbonding interactions (NICS) in Na2F-CNT@BF4 at the bond critical point (BCP). The charge transfer from BF4@CNT to superalkali entity Na2F has been observed, stabilizing Na2F-CNT@BF4. The calculated intensity as well as assignments of infrared spectra of CNT@BF4 and electronic transitions are compared with Na2F-CNT@BF4, which provides CNT’s polarization properties via interactions with Na2F and BF4. The charge transfer from CNT@BF4 to Na2F results in a large dipole moment (7.8969 D) of the complex, implying that its polarizability (588.4983 au) is comparable to that of CNT@BF4; however, the hyperpolarizability (4551.9858 au) of Na2F-CNT@BF4 is much higher than that of BF4@CNT. In this way, we hope that Na2F-CNT@BF4 will pique the interest of researchers interested in expanding the electro-optical applications of Na2F-CNT@BF4.