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Various quantities of (E)-4-methoxy-N'-(2-(trifluoromethyl)benzylidene) benzohydrazide (EMT) adsorbed on colloidal silver nanoparticles were studied using SERS and results were compared to the normal Raman spectrum. DFT calculations were used to validate experimental findings. Theoretically, the structures of the EMT and EMT-Ag6 systems were optimized. The UV-Vis spectral analysis’s red shift and lower intensity behaviour shows that EMT has chemisorbed on to Ag nanoparticles. Charge transfer (CT) from Ag to EMT is highlighted by FMO analysis. The CT interaction in EMT and EMT-Ag6 was further verified by MEP and Mulliken charge analyses. The EMT was adsorbed on Ag nanoparticles with tilted orientation and orientation changes with colloidal concentration, according to SERS spectrum analysis.

The recent COVID-19 virus caused hundreds of thousands of deaths and a widespread fear that threatened the health security in the world. Chloroquine derivatives are among the drugs tested against corona virus pandemic in 2020 and have shown an apparent effectiveness. In this work, tryptamine derivatives have been identified as antiviral for treatment of COVID-19 diseases combining DFT and molecular docking and their activity is compared with the 7-chloro-4-hydrazinoquinoline drug. Using density functional theory, molecular geometries and electronic properties have been investigated. The frontier orbitals analysis has been predicted to determine charge transfer within molecules. The density of states was determined to perform a better description of the FMOs. The molecular electrostatic potential maps have been calculated to provide details about the molecule’s chemical reactivity and also to explain intermolecular interactions. All these studies help us a great in determining biological activities of the compounds described. Finally docking calculations were performed using AutoDock and Patchdock servers to assess the tryptamine derivative’s therapeutic activities against corona virus diseases. [ FROM AUTHOR] Copyright of Polycyclic Aromatic Compounds is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all Abstracts.)

Surface-enhanced Raman scattering is a tool for improving the Raman signal of biomolecules using nanosized metal substrates. Nanomaterials such as nanocages and nanoclusters find vast applications in sensing materials, adsorption and medical devices. The characterization sensing parameters of melamine with Al12/B12-N12/P12 nanocages were investigated using quantum chemical calculations. Charge transfer from melamine (Me) to nanocage is demonstrated by Mulliken charge and natural bond orbital analysis. Furthermore, the analysis of the highest occupied molecular orbital and lowest unoccupied molecular orbital give the localization of electron density. Adsorption energies of − 115.2221, − 119.0147, − 118.8001 and − 92.8714 kcal/mol are found for AlN-Me, AlP-Me, BN-Me and BP-Me clusters. The second hyperpolarizability of all nanocage-Me systems shows very large enhancement. Melamine adsorption over nanocages causes change in electronic properties resulting in Raman mode’s enhancement and variation in chemical properties. The nanocages are cationic and melamine is anionic.

Spectroscopic investigations of 1-phenyl -2,3-dimethyl-5-oxo-1,2-dihydro-1H-pyrazol-4-ammonium 2[(2-carboxyphenyl) disulfanyl]benzoate (PACB) reported experimentally and theoretically. NH-O interaction is observed and there is a very large downshift for NH-O stretching frequency. Reactive sites are identified from the chemical and electronic properties. For PACB the maximum repulsion was around H33, H55 and H57 atom. LOL shows red regions between C-C and blue around C atoms are surrounded by a delocalized electron cloud. The red ring is a hallmark of electron density depletion from the NCI plot due to electrostatic repulsion and its existences suggests that coordination sphere for PACB is minimally strained around the central ion. Atomic contact energy values and high score of the docking results obtained propose that, PACB may have inhibitory properties and have a significant function in pharmacological chemistry. Molecular dynamics simulation was performed to validate the stability of the title compound with the Bovine thrombin-activatable fibrinolysis inhibitor protein.Communicated by Ramaswamy H. Sarma.

Using nanosized metal substrates, surface-enhanced Raman scattering (SERS) is a tool for improving the Raman signal of biomolecules. For detection, SERS has gained much popularity and an important role in determining chemical composition. In the present study, SERS spectra of 2-methyl-4-(4-methylpiperazin-1-yl)-10H-thieno[2,3-b][1,5]benzodiazepine (olanzapine) (MPTB) were investigated on silver and silver-gold metal substrates (SERSitive, Warsaw, Poland) at different concentrations. Also, different chemical and electronic properties are investigated using DFT calculations. The ring and other functional modes in SERS change in frequency values with variations in intensity for all concentrations. The molecule is oriented in a tilted manner with respect to Ag and Ag-Au.

Adsorption of 2,4,6-tribromoaniline (BA), 2,4,6-trifluoroaniline (FA) and 2,4,6-trichloroaniline (CA) onto the surface of coronene/fullerene/fullerene-like nanocages was investigated by theoretical...

The kinetics of hydrogen atom abstraction from methyl propionate (MePr), a biodiesel model, by •H and •CH3 radicals, have been studied. Here, we employ density functional theory (BB1K, BMK, M06-2X, M08-HX, and ωB97XD) and ab initio (MP2, CBS-QB3, and G3) calculations. Rate coefficients of each of six-bimolecular reaction pathways of MePr oxidation were calculated using the conventional transition state theory (TST) with Eckart (Eck) tunneling correction over a wide temperature range, 700-1600 K at pressure 1.0 atm. Branching ratios analysis of different reaction channels indicates that abstraction of H atom from Cα is the most dominated route for MePr fuel consumption. However, rate constants of H-atom abstraction from the terminal methyl groups increase with rising of temperature for both •H and •CH3 radicals.

The performance of nanotubes (NT) of carbon (CC), aluminum-nitrogen (AlN), and boron-nitrogen (BN) as a sensor and nanocarrier for mercaptopurine (MCP) was investigated by means of a theoretical approach. The calculated negative values of adsorption energy showed the interaction and adsorption of MCP. HOMO and LUMO distributions were only found on the NT counter portion of the drug-nanotube not on MCP for AlN-NT and BN-NT while HOMO is over MCP and LUMO are over NT for CC-NT. The polarizability of MCP-NTs is greater than that of MCP. Raman wavenumbers of MCP are enhanced in NTs and hence NTs can act as a sensor for the detection of MCP. Solvent dependency on adsorption behavior is also presented in the manuscript, where we found that the AlN nanotube showed exceptionally high free energy of adsorption over other nanotubes in all solvent mediums. Solvation-free energies were also reported. Noncovalent interaction scattered plot also showed significant intermolecular interaction between AlN nanotubes and the mercaptopurine when compared to other nanotubes under study. To find the antiviral activity of MCP and MCP-NTs against antiviral activities, docking and molecular dynamics simulations were performed with 1HMP PDB. Recovery times show that MCP desorption occurs quickly. The MD simulations and docking results show that BN and CC-NTs with MCP show good activity as drug carriers.

Three aminobenzoate derivatives, benzocaine (B1), butamben (B2) and n-pentyl 4-aminobenzoate (B3) were analyzed for the structural, nonlinear optical, electronic and biological properties. The func...

The Gaussian 09 DFT tool is used to investigate the formational electronic behaviour, reactivity analysis and biological properties of fluphenazine dihydrochloride (FDD). The quantum computation is used to determine the spectroscopic and vibrational assignments of FDD. The NBO method explains charge transfer and molecular interactions. Energy gap values are determined using FMO analysis in different solvents and toluene is a better solvent due to higher value of solvation energy. The UV-visible spectra are investigated in various solvents using the TD-DFT method. Electrostatic potential, the wave function related properties such as LOL, NCI and RDG are determined in gaseous phase. Furthermore, the drug likeness is analyzed. At last, a docking study with MD simulation is used to investigate FDD's antiviral activity against SARS-CoV-2 main protease.

A new synthetic chelating N–hydroxy–N–trioctyl iminophosphorane (HTIP) was prepared through the reaction of trioctylphosphine oxide (TOPO) with N–hydroxylamine hydrochloride in the presence of a Lewis acid (AlCl3 ). Specifications for the HTIP chelating ligand were successfully determined using many analytical techniques,13C–NMR,1H–NMR, FTIR, EDX, and GC–MS analyses, which assured a reasonable synthesis of the HTIP ligand. The ability of HTIP to retain U(VI) ions was investigated. The optimum experimental factors, pH value, experimental time, initial U(VI) ion concentration, HTIP dosage, ambient temperature, and eluents, were attained with solvent extraction techniques. The utmost retention capacity of HTIP/CHCl3 was 247.5 mg/g; it was achieved at pH = 3.0, 25◦C, with 30 min of shaking and 0.99 × 10−3 mol/L. From the stoichiometric calculations, approximately 1.5 hydrogen atoms are released during the extraction at pH 3.0, and 4.0 moles of HTIP ligand were responsible for chelation of one mole of uranyl ions. According to kinetic studies, the pseudo–first order model accurately predicted the kinetics of U(VI) extraction by HTIP ligand with a retention power of 245.47 mg/g. The thermodynamic parameters ∆S◦, ∆H◦, and ∆G◦ were also calculated; the extraction process was predicted as an exothermic, spontaneous, and advantageous extraction at low temperatures. As the temperature increased, the value of ∆G◦ increased. The elution of uranium ions from the loaded HTIP/CHCl3 was achieved using 2.0 mol of H2SO4 with a 99.0% efficiency rate. Finally, the extended variables were used to obtain a uranium concentrate (Na2U2O7, Y.C) with a uranium grade of 69.93% and purity of 93.24%. © 2022 by the authors. Licensee MDPI, Basel, Switzerland. Princess Nourah Bint Abdulrahman University, PNU: PNURSP2022R13 The authors express their gratitude for the support from Princess Nourah bint Abdulrahman University Researchers Supporting Project number (PNURSP2022R13), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia.

The performance of nanotubes (NT) of carbon (CC), aluminium-nitrogen (AlN) and boron-nitrogen (BN) as a sensor and nanocarrier for mercaptopurine (MCP) was investigated by means of theoretical approach. The calculated negative values of adsorption energy showed the interaction and adsorption of the drug. HOMO and LUMO distributions were only found on the NT counter portion of drug-nanotube not on MCP for AlN-NT and BN-NT while HOMO is over MCP and LUMO is over NT for CC-NT. The polarizability of MCP-NTs is greater than that of MCP. Raman wavenumbers of MCP are enhanced in NTs and hence NTs can act as a sensor for detection of MCP. Solvent dependency on adsorption behavior is also presented in the manuscript, where we found that AlN nanotube showed exceptionally high free energy of adsorption over other nanotubes in all solvent medium. Solvation free energies were also reported. Non covalent interaction scattered plot also showed significant inter molecular interaction between AlN nanotubes and the mercaptopurine when compared to other nanotubes under study.

Using density functional theory, the adsorption of valproic acid onto the surface of fullerene-like nanocages was investigated. Valproic acid interact the nanocages through the carboxylic group with energies of -144.14, -109.71, -105.22 and -84.96 kcal/mol. The FMOs energy levels were considerably altered upon adsorption, resulting in a reduction in energy gap and increase in electrical conductivity. This suggests that nanocages could be used as sensors as well as options for drug administration in biological systems. Solvation effects in water are also reported.

Using density functional theory, the adsorption of valproic acid onto the surface of fullerene-like nanocages was investigated. Valproic acid interacts with the nanocages through the carboxylic group with energies of - 144.14, - 109.71, - 105.22, and - 84.96 kcal/mol. The frontier molecular orbital (FMO) energy levels were considerably altered upon adsorption, resulting in a reduction in energy gap and increase in electrical conductivity. This suggests that nanocages could be used as sensors as well as options for drug administration in biological systems. Solvation effects in water are also reported.

Valacyclovir HCl hydrate, acyclovir and ganciclovir are three commonly used anti viral drugs which are guanidine derivatives with ether side chain and all of them act by interfering with the viral DNA production. This manuscript tries to examine the structure and properties of these three purine based compounds using electronic structure methods and molecular mechanics. Density functional theory was used to optimize the ground state geometry of the molecules from frontier molecular orbitals are analyzed using B3LYP functional. They give wealth of information about the electronic properties and descriptors, which will enable to predict the bioactivity of the molecules. As the electrons interact with electromagnetic radiations, electronic excitations between different energy levels are analyzed in detail using TD-DFT with CAM-B3LYP orbital. Calculations shows that they are with excellent light-harvesting efficiency hence be used as photo sensitizers. Molecular docking studies predict the biological activity of the molecules against ADP-thymidine kinase, hence inhibits its action, subsequently affecting the viral DNA production. It is interesting to see that on adsorption with a graphene quantum dot surface, all adsorbed complex show enhancement in the Raman activity giving Surface Enhanced Raman Spectra (SERS) when studied using dispersion force corrected ω-B97XD functional. This can be used for the detection of these drugs in a pharmacological or biological sample. Interestingly the graphene drug molecular assembly shows enhanced biological activity when compared to individual drug molecules.

Theoretical vibrational spectra of indole (IND) and its binary combination with dichloromethane (DC) in various solvents were computed to track the impact of molecular interactions on drug spectral characteristics. When transitioning from plain drug to complexes, 3561.26 cm− 1 mode of the IND displays a substantial shift in peak location. The 3561.26 band shows (~ 15.58) red shift upon dilution. The geometry of drug and IND-DC complex in various solvents was calculated using quantum chemical calculation utilizing DFT.

Theoretical calculations were done using density functional theory in order to determine vibrational frequencies, infrared and Raman intensities, MEP, NLO and NBO properties of the Hydrochlorothiazide-isoniazid (HCTA-IN) and Hydrochlorothiazide-malonamide (HCTA-MA) cocrystals. Electron donor-acceptor due to charge transfer mechanism has been scrutinized by the NBO investigation. First order hyperpolarizability of HCTA-IN and HCTA-MA are 19.86 and 7.80 times that of urea. The downshift of NH2, NH and C O modes are due to strong hyper conjugative interactions are indicated in NBO analysis. TD-DFT analysis was used to generate the theoretical electronic spectra, which shows a charge transfer process between the thiazide and isoniazid in HCTA-IN complex. Light harvesting efficiency studies reveal efficient photosensitization potential and photochemical modeling proves the efficiency of the cocrystal to be used in dye sensitized solar cells. Title compounds are docked with glucocorticoid receptor (1NHZ) and peroxidase manganese-dependent I (1YYD).

Investigation of the adsorption properties of 3-(adamantan-1-yl)-4-phenyl-1-[(4-phenylpiperazin-yl)methyl]-1H-1,2,4-triazole-5(4H)-thione (APT) with metal clusters (mC: Ag, Au and Cu) are reported using DFT method. APT is found to form stable cluster with transition metal clusters of copper, silver and gold. The drug-cluster complexation energy is slightly more for the gold nanocluster-drug complex. Dipole moment of the drug-gold cluster is found to be higher than that of the other systems. SERS studies demonstrate improved Raman signals for multiple wavenumbers of all APT-metal cluster complexes. Different spectroscopic, chemical and electronic properties are also investigated.