Mulliken Atomic Charges Research Articles

A COMPUTATIONAL DENSITY FUNCTIONAL THEORY INVESTIGATION OF THE INTERACTION OF BORON NITRIDE NANOSHEETS WITH MULTIPLE MOLECULAR HYDROGENS

In this study, the adsorption of molecular hydrogens (H2) on boron nitride (BN) frameworks was investigated using the density functional theory (DFT) technique. The results of optimized geometric structures revealed that molecular hydrogens were favourably adsorbed on top of nitrogen atoms in the BN monolayers. In addition, the optimized equilibrium geometries were utilized to calculate the electronic structures, including binding energies, energies of the highest and lowest occupied molecular orbitals (HOMO and LUMO), molecular electrostatic potentials (MEPs), and Mulliken atomic charges (MACs). The binding energy values were calculated to be approximately 0.01 eV per molecular hydrogen based on the results. As the number of molecular hydrogens increased in the BN framework, a slight increase was observed in the binding energy value per hydrogen molecule. Furthermore, the HOMO–LUMO gaps were determined with the corresponding energy values of about 6 eV. Regarding the Frontier molecular orbitals (FMOs) diagrams, the electron densities for the HOMOs of the studied systems were primarily focused on the N-edges. Conversely, for the LUMO, the electron density distribution was localized in the B-edges of titled systems. In the context of hydrogen adsorption on BN nanosheets, the MEP maps indicated that hydrogen atoms at the N-edges of the studied systems exhibited the most positive electrostatic potentials in this research. In contrast, surfaces with negative electrostatic potential surfaces were situated in the region close to B-edges. The computed results are consistent with the corresponding Mulliken atomic charge distributions. From the analyses of the Mulliken scheme, all nitrogen atoms displayed negative charge values, and positive charges were found on the boron atoms. The DFT results obtained in this report may serve as the foundation for developing hydrogen storage materials

Synthesis, spectral, quantum chemical, biological, molecular docking and mathematical investigations of piperidin-4-one oxime picrates

By using spectroscopic techniques, the 3,5-diethyl-2r,6c-diarylpiperidin-4-one oxime picrates (DDPPOP and DDMPPOP) were characterised by elemental analysis, FT-IR, 1H, 13C and 2D NMR and mass spectral techniques. The compounds follow a normal chair conformation with all substituents orientated equatorially, as indicated by the reported chemical shifts and coupling constants from the NMR spectral data. The optimised molecular structures of the title compounds were done by using DFT method with B3LYP/6-311++G(d,p) theory. According to the calculated first hyperpolarizability (β0) values of the compounds display non-linear optical (NLO) behaviour. The molecule may have undergone intra-molecular charge transfer, according to the HOMO–LUMO transition. The reactive sites of the title molecule was analysed by using the Molecular Electrostatic Potential (MEP) surface. The Mulliken atomic charges were calculated by using same basis set. The antibacterial and antifungal activity of the title compounds was examined by biological study. Docking studies were thoroughly conducted to establish knowledge regarding the molecular interactions between protein and this compound. This study is further developed and uses the idea of graph colouring in mathematical computation to support the molecular structure we created using NMR spectroscopy.

Interactions between Diphenylamine with 2-Hydroxypropyl β-Cyclodextrin based on Spectral, Biological and Theoretical Investigations

The inclusion complex of diphenylamine (DPA) in 2-hydroxypropyl β-cyclodextrin (HP-β-CD) was synthesized by a co-precipitation method. The structure and molecular properties of the newly synthesized inclusion complex (DPA: HP-β-CD) were investigated along with a β-cyclodextrin (β-CD) inclusion complex (DPA: β-CD) using various analytical and theoretical methods. Phase solubility, absorption, fluorescence, Fourier transform-Infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD) and scanning electron microscope (SEM) techniques were used to investigate the structural properties of the DPA before and after being encapsulated by the CDs (β-CD and HP-β-CD). Furthermore, the antioxidant and antibacterial activities were evaluated for DPA and the inclusion complexes (DPA: β-CD and DPA: HP-β-CD). The structure of the inclusion complexes was proposed based on the experimental results and their structural optimization was done using Becke’s three parameter density functional theory using Lee-Yang-Parr’s 3-21 G method in the gas phase. Then the various theoretical molecular properties, such as frontier molecular orbitals (FMO), molecular electrostatic potential map (MEP), Mulliken atomic charges, natural bond orbitals (NBO), electron localization function (ELF), localized orbital locator (LOL), quantum theory of atoms in a molecule (QTAIM) and noncovalent interactions—reduced density gradient (NCI-RDG) were studied for DPA and its inclusion complexes using the Gaussian 09 W software and Multiwfn 3.8 tool.

Synthesis, spectroscopic characterizations, single crystal XRD, supramolecular assembly inspection via hirshfeld surface analysis, and DFT study of a hydroxy functionalized schiff base Cu(II) complex

The current work describes the synthesis, characterization, and theoretical investigation of a copper complex with a hydroxy functionalized Schiff base ligand. The complex [Cu(DHBEE)2] was characterized by UV–Visible, FT-IR, and mass spectrometry. The crystalline nature of [Cu(DHBEE)2] was examined using X-ray diffraction (XRD), revealing that the Cu2+ ion occupies a center of inversion symmetry and adopts a square planar geometry. The supramolecular assembly was stabilized by non-covalent interactions, which were further probed by Hirshfeld surface analysis along with the computation of energy of interaction between the molecular pairs and energy frameworks. Void analysis was carried out to check whether large cavities were present in the crystal or not. Density functional theory utilizing the B3LYP/LANL2DZ/6–311 G (d) level of theory indicates that the calculated bond lengths and bond angles of [Cu(DHBEE)2] support X-ray data. The O4 and O4i atoms are the sites for electrophilic attack due to the obtained results from the MEP map, Mulliken atomic charge, and Fukui function. Furthermore, HOMO-LUMO analysis verifies the enhanced chemical reactivity of the complex as compared to the ligand. The value of the energy gap for complex and ligand displays that the order of charge transfer rises as follows: [Cu(DHBEE)2] > (DHBEE).

Spectroscopic, Quantum Chemical and Molecular Docking Studies on N-(9H-Purin-6-yl) Benzamide: A Potent Antimalarial Agent

This study presents a comprehensive analysis of N-(9H-purin-6-yl) Benzamide (NPB) using a combination of Density Functional Theory (DFT) calculations and experimental techniques. The molecular configuration of NPB was optimized using DFT/B3LYP method employing the 6-311++G (d,p) basis set. The fundamental frequencies were calculated and assigned, which agree well with the experimental results. The UV-Vis spectroscopic analyses, HOMO-LUMO energy gap assessment, Molecular Electrostatic Potential calculation, and Mulliken charge analysis, Fukui function calculation and Natural bond orbital analysis were performed for the NPB molecule. The UV-Visible spectral analysis, which predicts the transition of bonding and anti-bonding π-electrons from the purine ring to the aromatic ring of the NPB molecule. A smaller energy gap in the HOMO-LUMO analysis reveals that the NPB molecule is more reactive and Mulliken atomic charge distribution analysis indicates that the carbon atoms are highly influenced by their substituents. Natural Bond Orbital (NBO) analysis was employed to investigate the bonding within the NPB molecule. The Fukui function analysis indicates that the biological activity of the NPB molecule. In order to analyze the structure of NPB molecule, the thermodynamic properties in the temperature range 100–1000 K were obtained by thermodynamic analysis software SHERMO calculator. The molecular docking analysis was carried out for antimalarial proteins (5ZNC, 2BMA, 7E27, 7E26) using auto-docking simulations. This computational method confirms the bioactivity and drug-likeness parameters of the NPB molecule. The molecular docking results predicts the formation of hydrogen bonds between the ligand (NPB) and the protein receptors. Based on these findings, this study establishes that the distinctive methodology applied to identify NPB molecule as a potential candidate for an antimalarial drug designing, which is suitable for in vivo and in vitro investigations.

Insight with Crystallization, Quantum Computation, Hirshfeld, ELF/LOL and Molecular Docking of Syringic Acid Nicotinamide Cocrystal as Potent Mycobacterium Tuberculosis Inhibitor

Tuberculosis (TB) is a recurring and progressive illness with a high global death rate. MycobacteriumTB drug resistance is a serious impediment to allelopathy therapy. Contemplating combinatorial drug delivery (pharmaceutical cocrystal) as anti-TB medicines targeting Mycobacterium tuberculosis’s active site can be an alternative strategy. The syringic acid nicotinamide (SYNI) cocrystal was synthesized in this work through slow evaporation technique and was examined based on quantum chemical calculations, Hirshfeld analysis, electron localization analysis and molecular docking. The intended vibrational wavenumbers were allocated a PED value and related with experimental frequencies. The UV–Visible absorption spectra of the cocrystal in the liquid phase (ethanol) were revealed as [Formula: see text]* electronic transitions. The HOMO–LUMO values, band gap, molecular electrostatic potential and Mulliken atomic charge distribution of the molecule were evaluated to estimate its stability and molecular reactivity. The molecule’s second-order perturbation energy [Formula: see text] standards were determined by means of natural bond orbital analysis, and potential reactive site was assessed using local reactivity descriptors. Hirshfeld analysis revealed that H…H (44.9%), O…H/H…O (39.3%), C…H/H…C (6.1%), N…H/H…N (5.3%) and C…C (2.4%) have the major percentage contributions from the most significant interactions. The topological features of the SYNI cocrystal were assessed through electron localization function based on color gradient. The binding ability of SYNI cocrystal with the Mycobacterium tuberculosis associated proteins was evaluated through docking and their binding scores fall between the range of −9.1 kcal/mol and −10.8 kcal/mol, which confirms the better binding ability and makes SYNI cocrystal a potent medication against TB.

Computational study: Synthesis, spectroscopic (UV–vis, IR, NMR), antibacterial, antifungal, antioxidant, molecular docking and ADME of new (E)-5-(1-(2-(4-(2,4-dichlorophenyl)thiazol-2-yl)hydrazineylidene)ethyl)-2,4-dimethylthiazole

In this paper, we describe the synthesis of a novel (E)-5-(1-(2-(4-(2,4-dichlorophenyl)thiazol-2-yl)hydrazineylidene)ethyl)-2,4-dimethylthiazole (DCPTHT) via multicomponent reaction between 1-(2,4-dimethylthiazol-5-yl)ethan-1-one, thiosemicarbazide and 2-bromo-1-(2,4-dichlorophenyl)ethan-1-one. The structure of DCPTHT was confirmed on the basis of FT-IR, 1HNMR and 13C NMR characterizations. The molecular structure of the novel thiazole derivative was examined using density functional theory (DFT) simulations at the B3LYP/6-311G (d,p) level of theory. Molecular simulations were made for total energy, HOMO and LUMO energy, and Mulliken atomic charges. In a dimethyl sulfoxide solvent, the electronic absorption spectra were acquired, and TD-DFT calculations were used to discuss the band assignments. By correlating the experimental and simulated spectra, NMR assignments and interpretations were also established. Remarkably, antibacterial and antifungal screening was used to examine the biological profile of DCPTHT. Antibacterial screening was performed against E. coli, B. subtilis, P. aeruginosa, and MRSA while the antifungal screening was performed against A. niger and C. albicans. It was found that the newly synthesized thiazole derivative demonstrated potent antifungal activity on the investigated fungal species. Molecular docking study against cytochrome P450 14α-sterol demethylase (CYP51) (PDB id: 5v5z). Furthermore, ADME predictions are also discussed. The molecular docking studies revealed mostly hydrophobic and van der Waals interactions with different amino acid residues.

Synthesis, experimental and theoretical studies of morpholinium bromide single crystal for NLO application

Due to the electronic applications, non-linear optical (NLO) materials are receiving research attention. A non-linear optical material, morpholinium bromide (MBr) single crystal with dimensions of 14 × 9 × 3 mm3 was grown successfully by slow evaporation solution growth technique. The synthesized crystal belongs to monoclinic crystal with space group P21/c, which was confirmed through single crystal XRD (SXRD) analysis. Further, powder XRD analysis was used to record several dispersion peaks and the presence of dispersion peak positions for the as-grown material is correlated with the scattering peak state. The optimised molecular structure, HOMO-LUMO, NBO, MEP and Mulliken atomic charges of MBr crystal were theoretically investigated using B3LYP with a 6–311 G ++(d, p) basis set. FTIR studies revelas the functional components present in the grown material. The optical band gap was found to be 3.3 eV with a transmittance cut-off wavelength of 362 nm. TG-DTA analysis was done to understand the as-grown MBr crystal's temperature withstanding capability by assessing the weight loss associated with the corresponding decomposition peak. The potential of the crystal to stand up to laser power is investigated using laser damage threshold (LDT) studies. The Z-scan study is implemented to the polished MBr crystal to assess its nonlinear refractive index (n2), absorption coefficient (β) and susceptibility χ(3) for its usefulness in optoelectronic applications.

Structural, mechanical, electronic, optical and thermodynamic features of lead free oxide perovskites AMnO3 (A=Ca, Sr, Ba): DFT simulation based comparative study

Perovskite oxides with transition metals have been subjected to a lot of concern in the recent time having their exclusive physical and chemical property. Due to ferroelectric character these types of materials have huge technological applications in worldwide. In the existing project, the crystal structure stability, single and polycrystalline bulk properties, electron-charge density, photon and temperature related optical as well as thermal features of perovskite oxides AMnO3 (A = Ca, Sr, Ba) have been investigated through DFT simulation with CASTEP code. Very good accordance in the investigated and synthesized lattice parameters is found. Mechanical stabilities of phases AMnO3 (A = Ca, Sr, Ba) are ensured from the investigated elastic stiffness constants. Ductile nature of compounds AMnO3 (A = Ca, Sr, Ba) are ensured from the study of Pugh's and Poisson's ratios. Hardness calculations ensured that all the studied materials are hard in nature where SrMnO3 has little bit higher hardness nature compared to others. Very high machinability index of CaMnO3 confirmed its suitable industrial application compared to the rest two compounds. Anisotropic character of AMnO3 (A = Ca, Sr, Ba) is observed from the analysis of elastic anisotropy factor. Band structure calculations with up-spin and down-spin reveal the metallic and semi-metallic nature of AMnO3 (A = Ca, Sr, Ba) respectively. Ionic and covalent bonded nature of AMnO3 (A = Ca, Sr, Ba) are confirmed from the Mulliken atomic population and charge density calculations. Very high absorption and conductivity of AMnO3 (A = Ca, Sr, Ba) have been observed in the ultraviolet energy site which ensure their possible applications in optical devices operates at UV energy regions. The dielectric function make sure the metallic nature of AMnO3 (A = Ca, Sr, Ba) as the actual value approaches to zero from negative energy region. Comparatively high Debye temperature of AMnO3 (A = Ca, Sr, Ba) revealed that these compounds are thermally more conductive where CaMnO3 is more conductive than the rest two materials. Very low value of Kmin of material BaMnO3 ensured that this phase has more possibility to use in thermal barrier coating materials (TBC) than CaMnO3 and SrMnO3 materials.

Spectroscopic, Biological, and Topological Insights on Lemonol as a Potential Anticancer Agent.

A monoterpene alcohol known as lemonol was investigated experimentally as well as theoretically in order to gain insights into its geometrical structure, vibrational frequencies, solvent effects on electronic properties, molecular electrostatic potential, Mulliken atomic charge distribution, natural bond orbital, and Nonlinear Optical properties. The frontier molecular orbital energy gap values of 5.9084 eV (gas), 5.9261 eV (ethanol), 5.9185 eV (chloroform), 5.9253 eV (acetone), and 5.9176 eV (diethyl ether) were predicted, and it shows the kinetic stability and chemical reactivity of lemonol. Topological studies were conducted using Multiwfn software to understand the binding sites and weak interactions in lemonol. The antiproliferative effect of lemonol against the breast cancer cell line Michigan Cancer Foundation (MCF-7) was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, while nuclear damage, condensation, and reactive oxygen species generation were identified using acridine orange/ethidium bromide, propidium iodide, and dichlorodihydrofluorescein diacetate staining. The theoretical and experimental findings are highly correlated, confirming the structure, and the results of in vitro studies suggest that lemonol acts as a potent inhibitor against the human breast cancer cell line MCF-7, highlighting its strong antiproliferative activity.

Evaluating the in vitro antidiabetic, antibacterial and antioxidant properties of copper(II) Schiff base complexes: An experimental and computational studies

In recent years, metal-based compounds have been explored as potential remedies for majorhealth issues such as diabetes, bacterial infections, and oxidative stress, which impact the general well-being of humans globally. Diabetes, bacterial infections, and oxidative stress are major health concerns affecting millions worldwide. Researchers have been exploring the use of metal-based compounds as potential treatments for these conditions. In our quest towards identifying biologically viable metal-based compounds, three novel Cu(II) complexes were synthesized from halogen-substituted ON donor Schiff base ligands. These ligands were obtained by condensing 2-hydroxybenzldehyde with three different halogen-substituted anilines. The ligands and their complexes were characterized using various spectroscopic techniques such as 1H and 13C nuclear magnetic resonance, Fourier Transform-Infrared, Ultraviolet–visible spectra, elemental analysis, mass spectrometry, and single-crystal X-ray spectroscopy to elucidate their structures. The compounds were screenedfor antidiabetic (α-glucose and α-amylase enzymes inhibition assay), antioxidant (2,2-diphenyl-1-picrylhydrazyl(DPPH), ferric reducing antioxidant potential (FRAP) assay, and nitric oxide(NO) radical scavenging), and antimicrobial activities. The pharmacological activity revealed that the efficacy of the ligands was enhanced upon coordination, and CuL3 is more potent among the complexes, having higher inhibition activity on α-glucosidase (IC50 = 100.1 μM) than the control, whose IC50 is 112.4 μM on the same enzyme. For radical scavenging activity, the results showed that the complexes have higher scavenging activity on DPPH radicals than their ligands and the control. For the FRAP assay, the complexes show higher activity than their ligands. Similarly, NO radical scavenging activity results indicate the ligands have higher activity than their complexes, while the complexes outperformed the control at all concentrations tested. The In vitro antibacterial results on some selected Gram-positive and Gram-negative bacteria revealed the complexes have higher antibacterial activity than their corresponding ligands, with CuL3 taking the lead, showing a MIC value of 4 g/mL on some of the bacteria tested. Also, density functional theory calculations at different levels of DFT and basis sets were used to investigate the optimized geometry, electronic structure (energy of HOMO and LUMO, Mulliken atomic charge, dipole moment, hardness, and softness, electrophilicity, and spectral properties) of the synthesized compounds. Molecular docking studies were carried out to investigate the binding affinity of the receptor proteins to other proteins and to establish the mechanism of action at the active sites.

Synthesis, Structural, Spectroscopic and Quantum Chemical Investigation of a Novel 1,4-Diamino-2,5-dichlorobenzenium Picrate Single Crystal: An Efficient NLO Material

A new organic nonlinear optical single crystal, 1,4-diamino-2,5-dichlorobenzenium picrate (DADCBP) has been successfully grown by solvent slow evaporation method. DADCBP crystallizes in a triclinic structure with the centrosymmetric space setup, P-1. The molecular structure of the grown crystal has been determined by NMR spectral analysis. The existence of discrete functional branches of the crystal has been identified by FTIR spectral study. The optical property of the title crystal has been measured by UV-Vis-NIR spectral analysis. PL spectra reveal the emission bands of the grown crystal. The thermal stability of the harvested crystal has been examined by the TG/DTA study. The dielectric constant and loss have been taken to locate the arrangement of charges in the grown crystal. The quantum chemical studies have been performed to analyze the HOMO/LUMO, molecular geometry, and mulliken atomic charge by B3LYP at the 6-311++G (d,p) level of theory. H···H, O···H, C···H, C···C various intermolecular interactions of hydrogen bonds in the DADCBP molecule have been visualized by the Hirshfeld surface analysis. The nonlinear optical (NLO) characteristics like nonlinear absorption coefficient (β), nonlinear refractive index (n2) and susceptibility (χ(3)) have been examined using the Z-scan technique.

Synthesis of 1-Piperoylpiperidine Investigated Through Spectroscopy, Quantum Computation, Pharmaceutical Activity, Docking and MD Simulation Against Breast Cancer

1-Piperoylpiperidine (1-PIP) was crystallized as a single unit by a slow evaporation process, and it was examined using XRD and FT-IR spectroscopy. The centrosymmetric monoclinic structure is confirmed by XRD. The functional groups were determined by experimental FT-IR range from 4000 to 400 cm−1. Density functional theory was used to do calculations on quantum chemistry on B3LYP/6-311++G (d,p) theory. The vibrational wavenumbers were calculated, and experimentally obtained were assigned and compared. The molecule’s reactivity and kinetic stability are revealed via molecular orbital research. The Mulliken atomic charge distribution and molecular electrostatic potential analyses provide additional evidence of the molecule’s reactive site. The electronic spectrum was computed through TD-DFT and the electronic transition was attained at π→π*. The molecule’s bioactivity is shown by the natural bond orbital analysis. The efficiency and contribution of interactions between various atoms were evaluated using the Hirshfeld analysis. The DPPH assay was performed to access the antioxidant ability of 1-PIP. The disk diffusion test exhibited the antibacterial efficiency of 1-PIP molecule. The safety profile of 1-PIP was confirmed through physiochemical and pharmacokinetic predictions. In silico docking evaluation was performed for 1-PIP against 10 breast cancer-aided proteins and the higher binding affinity was recorded for NAMPT, which was further investigated through molecular dynamic (MD) simulation. MD simulation for a time period of 50 ns confirmed the stability of 1-PIP bounded NAMPT structure.

Estimation of dipole moments by Solvatochromic shift method, spectroscopic analysis of UV–Visible, HOMO-LUMO, ESP map, Mulliken atomic charges, NBO and NLO properties of benzofuran derivative

Solvatochromic shift method has been used to estimate ground state (μg) and excited state (μe) dipole moments of benzofuran derivative (5NFMOT) at room temperature indifferent solvents. This method involves Lippert, Bakhshiev and Kawski-Chamma-Viallet equations. Reichardt microscopic solvent polarity parameter was used to calculate the change in dipole moment. Effect of solvents on absorption and fluorescence spectra was investigated using Kamlet and Catalan's MLR approach. Computational studies of benzofuran derivative were carried out using Gaussian 16. Geometry optimization was performed using DFT method at 6–311++G (d, p)/B3LYP basis set. UV–Visible spectra have been studied by using TD-DFT method for the same basis set. The μg was obtained from DFT method, whereas μe from TD-DFT method. It has been observed that both from experimentally and theoretically the ground state dipole moment is higher than the excited state dipole moment. HOMO-LUMO surfaces and Mulliken atomic charges have been studied in gas phase and solution. Furthermore, 3D plots of electrostatic potential map are used to identify reactive centers such as electrophilic and nucleophilic sites. NBO analysis is helpful to obtain stability and charge delocalization of the title molecule. Polarizablity, and hyper polarizability values were used to study the NLO properties.

(1E)-1-(2-pyrazinyl)ethanone thiosemicarbazone (PT) as a tyrosinase inhibitor with anti-browning activity: Spectroscopy, DFT and molecular docking studies

In this study, (1E)-1-(2-Pyrazinyl)ethanone thiosemicarbazone (PT) was synthesized and characterized using Fourier-transform infrared (FTIR), ultraviolet-visible (UV–Vis), proton nuclear magnetic resonance (1HNMR ) and carbon-13 nuclear magnetic resonance (13CNMR ) spectroscopy. The vibrational frequencies were analysed using the Vibrational Energy Distribution Analysis (VEDA) program. The chemical properties of PT, including electron density distribution and intramolecular interactions, were characterized using in-silico methods based on Mulliken atomic charges, molecular electrostatic potential (MEP), quantum theory of atoms in molecules and reduced density gradient noncovalent interaction approaches. PT exhibits a significant inhibitory effect on enzymatic browning (6 and 24 h) and tyrosinase enzymes (IC50 = 7.75 μM). Kinetic analysis shows that PT is a mixed-type inhibitor, with respective Km and Vmax values of 0.632 mM and 0.0044 μM/s, and that it forms a reversible enzyme-inhibitor interaction. The PT-tyrosinase interaction was experimentally evaluated based on 1D, second derivatives of 1D, 2D and 3D IR spectroscopy. Furthermore, analysis of absorption, distribution, metabolism, excretions and toxicity properties revealed good physicochemical properties of PT according to the drug scores and Lipinski's Rule of Five. Lastly, the mechanisms of PT against tyrosinase were visualized and supported by means of a molecular docking approach.

Characterization, biological evaluation and molecular docking of novel synthesised 2-arylamino-4-(naphth-2-yl)thiazoles

The compounds 2-arylamino-4-(naphth-2-yl)thiazole are synthesised and characterized by FT-IR,1H NMR, 13C NMR and mass spectroscopy. The geometry of the molecule was optimised using the Gaussian 09 software and the B3LYP/6-31G density functional theory (DFT) approach. The 2-arylamino-4-(naphth-2-yl)thiazoles' bond lengths and bond angles have all been studied. Vibrational bands to distinct structural groups and their relevance were predicted using vibrational spectra analysis and were shown to be reliable when compared to experimental data and literature observations. The Mulliken atomic charges have been calculated. The charge transfer within the molecule is confirmed by the computed energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO).

Vibrational spectroscopic analysis of 2, 3:4,5-Bis-O-(1-methylethylidene)beta-D-fructopyranose Sulfamate(Topiramate) by density functional method

2,3:4,5-Bis-O-(1-methylethylidene)-beta-D- fructopyranose sulfamate otherwise called as Topiramate is a drug used for the treatment of alcohol dependence. Topiramate is a safe and consistently efficacious medication for treating alcohol dependence. The spectroscopic properties of Topiramate are investigated by Fourier Transform Infrared (FT-IR), Fourier Transform Raman (FT-Raman), Fourier Transform Nuclear magnetic Resonsnce(FT-NMR) andUltra Violet Visible (UV–visible) spectroscopic techniques. The FTIR, FT-Raman, FT-NMR and UV–visible spectra of Topiramate have been recorded and analyzed. Theoretical vibrational frequencies, geometric parameters, thermodynamic properties, Natural population analysis and Mulliken atomic charges of Topiramateare obtained by the Restricted Hartree–Fock (RHF) and density functional theory (DFT) using 6–31 + G(d,p) basis set. The calculated harmonic vibrational frequencies for Topiramate are compared with the experimental values of FTIR and FT-Raman spectra. The observed and the calculated frequencies are found to be in good agreement. Stability of the molecule arising from hyperconjugative interactions and charge delocalization has been analysed using natural bond orbital (NBO) analysis. The first-order hyperpolarizability (βtot) and other related properties such as dipole moment(µ), polarizability(αo)values of the investigated molecule are computed using HF and DFT/B3LYP with 6–31 + G(d,p) basis set. The calculated results also show that the Topiramate molecule may have microscopic nonlinear optical (NLO) behaviour.

Exploring the Synergistic Effect of Tegafur-Syringic Acid Adduct Against Breast Cancer through DFT Computation, Spectroscopy, Pharmacokinetics and Molecular Docking Simulation

The most prevalent kind of cancer and the main reason for cancer-related deaths in women is breast cancer. Synergistic drug delivery plays an effective role in the treatment of cancer by targeting various proteins underlying different mechanism. In this present study, a thorough analysis of the tegafur syringic acid adduct compound using density functional theory, molecular docking and pharmacokinetic prediction has been done. The PED value was given to the estimated vibrational wavenumbers. The molecule’s UV-Vis absorption spectra in the gas phase and liquid phase (water), were exhibited as π→π* electronic transitions. In order to determine the stability and molecular reactivity of the molecule, the HOMO-LUMO energies, energy gap, molecular electrostatic potential surface and mulliken atomic charge distribution were determined. Natural bond orbital analysis was used to determine the molecule’s second order perturbation energy E(2) values and potential reactive location was revealed through local reactivity descriptors. The Hirshfeld surface analysis showed that H…H (40.9%), O…H/H…O (27.2%), C…C (8%), O…C/C…O (7.8%), F…H/H…F (5.9%), C…H/H…C (5.5%), and N…C/C…N (2.9%) have the highest percentage contributions of the most important interactions. Thermodynamic characteristics like enthalpy, specific heat capacity and entropy were calculated. The physiochemical, absorption, distribution, metabolism, excretion and toxicity (ADMET) properties were predicted and represented the safety profile of adduct compound and the docking studies exhibited the binding potential of the adduct against the breast cancer proteins and highest binding affinity was observed against GSK3β with docking score of −9.7 Kcal/mol.

Enhanced H2 adsorption on 2D B4N monolayer modified with Na atoms: A density functional theory exploration

In this study, H2 adsorption properties on two-dimensional (2D) B4N monolayer modified with Na atoms are comprehensively investigated via density functional theory (DFT). Our results expose the intrinsic 2D B4N monolayer barely adsorb H2 molecules owes to a weak H2 adsorption energy. However, Na atom can be strongly anchored on the surface of 2D B4N monolayer with a large binding energy, which results in that the metal clustering is prevented. Meanwhile, H2 adsorption energy is drastically enhanced by introduced Na atom on B4N monolayer. Moreover, Na/B4N complex can adsorb up to 10 H2 molecules with average adsorption energy of −0.109 eV/H2 while 2Na/B4N complex can adsorb up to 20 H2 molecules with average adsorption energy of −0.116 eV/H2. The obtained H2 adsorption energy falls into an optimal range between −0.1 eV/H2 and −0.8 eV/H2 for mobile hydrogen storage applications. Also, the hydrogen storage gravimetric density reaches 7.27 wt% and exceeds the latest objective of 6.5 wt% from U.S. Department of Energy (DOE). In addition, Mulliken atomic charges analysis, charges density difference and projected density of states systematically reveal H2 adsorption mechanisms mainly from polarization effect and orbital hybridization. Ab initio molecular dynamic (AIMD) simulations using Nose-Hoover (NH) chain thermostat under canonical (NVT) ensemble manifest H2 molecules can be easily released from the 2Na/B4N complex under indoor temperature at 300 K. Our theoretical study guarantee 2D B4N monolayer modified with Na atoms can be recognized as a prospective hydrogen storage material.

Spectroscopic Characterization, Quantum Chemical and Molecular Docking Studies on 1-Chloroanthraquinone: A Novel Oral Squamous Cell Carcinoma Drug

Anthraquinone derivatives are well recognized for their anticancer activities and pharmacological properties. In the present study, comprehensive theoretical and experimental FT-IR, FT-Raman, and UV-visible spectroscopic studies on the 1-Chloroanthraquinone (CAQ) molecule were carried out. The optimized molecular structure and harmonic vibrational frequencies was calculated using Gaussian 09 program. The experimental and calculated vibrational wavenumbers were assigned, which correlated well with the previous literature. The UV-visible absorption spectrum of the CAQ molecule was computed in the liquid phase (ethanol), which exhibits n–π* electronic transition, and the results were compared with the observed UV-visible spectrum. From the frontier molecular orbital analysis, the calculated energy gap value (4.03 eV) indicates that the CAQ molecule has a stable structure and the value was comparable with the band gap energy value of the reported bioactive molecules. The electron back donation from the carbonyl group oxygen atom to the benzene ring was identified using Mulliken atomic charge distribution analysis. Molecular electrostatic potential surface analysis confirms the reactive sites of the molecule. The natural bond orbital analysis validates electron back donation from the carbonyl group oxygen atom to the benzene ring of the CAQ molecule. The molecular docking analysis results that the CAQ molecule acts as a good inhibitor of histone deacetylase 6 (HDAC6) protein. HDAC6 protein is associated with oral squamous cell carcinoma. Thus, the present study paves the way for designing novel drugs for the treatment of oral squamous cell carcinoma.