Experimental (FT-IR and FT-Raman spectra) and Theoretical (Ab initio/HF, DFT/B3LYP) Study of 2-Amino-5-Chloropyridine and 2-Amino-6-Chloropyridine

The Fourier transform infrared (FT-IR) and FT-Raman spectra of 2-amino-5-chloropyridine (2A5CP) and 2-amino-6-chloropyridine (2A6CP) have been recorded in the regions 4000–400 cm-1 and 4000–100 cm-1, respectively. The observed FT-IR and FT-Raman data, a complete vibrational assignment and analysis of the fundamental modes of the compounds were carried out. All the geometrical parameters have been calculated by HF and DFT (B3LYP) methods with 6-311++G (d, p) basis set. The vibrational wavenumbers, IR intensities and Raman activities are calculated at the same theory levels used in geometry optimization. The calculated frequencies are scaled and compared with experimental values. The scaled B3LYP/6-311++G(d,p) results show the best agreement with the experimental values. The calculated HOMO–LUMO energies show that charge transfer occurs in the molecules. Keywords: FT-IR, FT-Raman, ab initio, DFT, 2-amino-5-chloropyridine, 2-amino-6-chloropyridine

Insights into solvation effects, spectroscopic, Hirshfeld surface Analysis, reactivity analysis and anti-Covid-19 ability of doxylamine succinate: Experimental, DFT, MD and docking simulations

In the present work, the experimental and theoretical reports on electronic and vibrational features of doxylamine succinate (DXS) are presented. The vibrational spectra were documented and wavenumbers were obtained theoretically assigned by means of potential energy distribution. In DXS, N-H…O and C-H…O intermolecular hydrogen bonding contacts are associated with O…H/H…O interactions. Solvation free energy (SFE) for DXS in water, methanol and DMSO, are −10.67, −10.95 and −10.61 eV/mol respectively. Interpretation of electrostatic potential, electron localization function (ELF), localized orbital locator (LOL) as well as atoms-in-molecules (AIM) analysis is also performed. Presence of non-covalent interactions is evident from the non-covalent interaction (NCI) isosurface. Molecular docking and simulations were used to determine the binding energy of DXS in order to investigate its potential activity against the SARS-CoV-2 protease

DFT and MD investigations of the biomolecules of phenothiazine derivatives: interactions with gold and water molecules and investigations in search of effective drug for SARS-CoV-2.

Theoretical analyses of two phenothiazine derivatives, 10-[3-(dimethylamino)-2-methylpropyl]phenothiazine-2-carbonitrile (CYM) and 2-[4-[3-(2-chlorophenothiazin-10-yl)propyl]piperazin-1-yl]ethanol (PAZ) are reported using density functional theory (DFT) and molecular dynamics (MD) simulations. Spectroscopic studies, different electronic and chemical parameters are predicted. Red and yellow in electrostatic potential plot is in rings and oxygen atom in PAZ and C equivalent to N and rings in CYM are sensitive to nucleophilic attacks. The blue in hydrogen atoms refer to electrophilic attack in both PAZ and CYM. Stability of the protein-ligand complex formed with these derivatives and angiotensin-converting enzyme 2 (ACE2) was investigated using MD simulation. Radius of gyration of C-alpha atom of 6VW1 displayed the conformational convergence toward a compact structure leading to stable 6VW1-ligand complex which are also in agreement with root mean square fluctuation (RMSF) values. Localized area predicts reactive sites for Au and H2O molecules interaction with these compounds for further practical applications. Charge density is localized on both molecules and also tries to move toward Au-Au dimer and water molecule and such they are expected to contribute to the sensing performance. Communicated by Ramaswamy H. Sarm

Structural, Spectral, Molecular Docking, and Molecular Dynamics Simulations of Phenylthiophene-2-Carboxylate Compounds as Potential Anticancer Agents

Important biological compounds, namely, methyl 3-amino-4-(4-bromophenyl)thiophene-2-carboxylate (BPTC) and methyl 3-amino-4-(4-chlorophenyl)thiophene-2-carboxylate (CPTC), were characterized using complementary techniques of Fourier transform infrared (FT-IR), Raman spectroscopy. Nuclear magnetic resonance spectroscopy (NMR) confirmed the structural features, while Ultra Violet–Visible Spectroscopy was used to investigate the electronic properties of both compounds. The quantum chemical calculations for both compounds were performed using the DFT/B3LYP functional with the 6-311++G(d,p) basis set. This study computes electrostatic potential observation, electron localization function (ELF) assessment, and atoms-in-molecules (AIM) analysis. In the present investigation, the global hardness, chemical softness, electrophilicity, nucleophilicity indices, and dipole moment of both compounds were calculated. In addition, a molecular docking analysis was conducted to determine the binding potential of target molecules with protein tyrosine phosphatase. A 200-ns molecular dynamics (MDs) simulation had been performed to assess the compound’s binding stability.</p

Cetylpyridinium Bromide/Polyvinyl Chloride for Substantially Efficient Capture of Rare Earth Elements from Chloride Solution

A new sorbent cetylpyridinium bromide/polyvinylchloride (CPB/PVC) was prepared and tested to extract rare earth elements (REEs) from their chloride solutions. It was identified by FTIR, TGA, SEM, EDX, and XRD. The impact of various factors such as pH, RE ion initial concentration, contacting time, and dose amount via sorption process was inspected. The optimum pH was 6.0, and the equilibrium contact time was reached at 60 min at 25 &deg;C. The prepared adsorbent (CPB/PVC) uptake capacity was 182.6 mg/g. The adsorption of RE ions onto the CPB/PVC sorbent was found to fit the Langmuir isotherm as well as pseudo-second-order models well. In addition, the thermodynamic parameters of RE ion sorption were found to be exothermic and spontaneous. The desorption of RE ions from the loaded CPB/PVC sorbent was investigated. It was observed that the optimum desorption was achieved at 1.0 M HCl for 60 min contact time at ambient room temperature and a 1:60 solid: liquid phase ratio (S:L). As a result, the prepared CPB/PVC sorbent was recognized as a competitor sorbent for REEs

Efficient Recovery of Rare Earth Elements and Zinc from Spent Ni–Metal Hydride Batteries: Statistical Studies

Considering how important rare earth elements (REEs) are for many different industries, it is important to separate them from other elements. An extractant that binds to REEs inexpensively and selectively even in the presence of interfering ions can be used to develop a useful separation method. This work was designed to recover REEs from spent nickel–metal hydride batteries using ammonium sulfate. The chemical composition of the Ni–MH batteries was examined. The operating leaching conditions of REE extraction from black powder were experimentally optimized. The optimal conditions for the dissolution of approximately 99.98% of REEs and almost all zinc were attained through use of a 300 g/L (NH4)2SO4 concentration after 180 min of leaching time and a 1:3 solid/liquid phase ratio at 120 °C. The kinetic data fit the chemical control model. The separation of total REEs and zinc was conducted under traditional conditions to produce both metal values in marketable forms. The work then shifted to separate cerium as an individual REE through acid baking with HCl, thus leaving pure cerium behind