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Context: The corrosion of mild steel is a significant issue in various industries, prompting the need for effective corrosion inhibitors. This study focuses on understanding the corrosion inhibition properties of organic compounds derived from isoxazole, namely series Iso(a), Iso(b), Iso(c), Iso(d), Iso(e), Iso(f), Iso(g), and Iso(h), which could have implications for materials science and industrial applications. By investigating the influence of different substitutions on these compounds, valuable insights can be gained into designing better corrosion inhibitors for practical use. Methods: Theoretical studies were conducted using density functional theory (DFT) with the B3LYP functional and the 6-31G (d,p) basis set. These calculations enabled the evaluation of various parameters including frontier orbital energies (EHOMO, ELUMO), energy gap (∆E), electronegativity (χ), absolute hardness (η), softness (σ), fraction of transferred electrons (∆N), as well as local properties such as natural atomic populations and Fukui indices. Additionally, molecular dynamics simulations were performed to study the adsorption behavior of the inhibitors on the surface of Fe (110). The simulations were conducted using Materials Studio version 8.0 software package using COMPASS force field to understand the impact of different functional groups on the inhibitors before and after adsorption on the iron surface. [ABSTRACT FROM AUTHOR]

The efficient hydrogen-production through the Aluminum-water reaction has become a prominent subject of interest. The impediment encountered in the reaction can be effectively alleviated by Aluminum-based alloy. In this study, density functional theory (DFT) was utilized to explore the mechanism of water decomposition stage on the surface of aluminum and gallium alloy (AGA). Through surface reaction calculations of 12 stable AGA configurations, it was gradually revealed that the optimal alloy ratio was gallium-to-aluminum at 3.5:1. Analysis of the density of states (DOS) indicated that the presence of gallium amplified the activity of surface aluminum. Moreover, frontier orbital theory and charge density maps confirmed that, due to the weak interaction between Ga and ions, the presence of H 2 inhibited Ga passivation, thereby enhancing the reactivity of AGA. This paper provided valuable insights into the surface reaction mechanisms of AGA using DFT, offering theoretical support for hydrogen production processes. • Density functional theory investigated the early stages of AGA-water reaction. • Modeling AGA (Ga proportions 73.8%–81.2%) yields 12 stable configurations. • Ga:Al = 3.5:1 exhibits highest energies for O 2 , H 2 O, and co-adsorption. • Ga enhances AGA's catalytic activity, shown in DOS graphs comparisons. • AGA plays dual roles in surface hydrogen dynamics. [ABSTRACT FROM AUTHOR]

This investigation employed computational methodologies to assess the therapeutic potential of derivatives (1–16) of pyridoxal isonicotinoyl hydrazone (PIH) as potential treatments for tuberculosis. Various computational techniques, including molecular dynamics simulation, molecular docking, density functional theory, and global chemical descriptors, were employed to analyze the interactions between the ligands and target proteins. Docking results indicated that ligands 6, 7, 8, and rifampin exhibited binding affinities of −8.4, −7.4, −9.2, and − 7.2 kcal mol−1, respectively, against mycobacterium tuberculosis enoyl acyl carrier protein reductase (INHA), with ligand 8 demonstrating superior inhibition. Molecular dynamics (MD) simulations were utilized to assess the stability of protein‐ligand interactions. Remarkably, the Root Mean Square Deviation (RMSD) of the INHA‐ligand 8 complex remained minimal, with peak values at.40,.56,.37, and.50 nm at temperatures of 300, 305, 310, and 320 K, respectively. This suggests superior stability compared to the reference drug rifampin and INHA complex, which exhibited an RMSD range of.2 to.8 nm at 300 K. Furthermore, analysis using Frontier Molecular Orbital (FMO) revealed that the Egap value of ligand 8 (4.407 eV) is lower than all the reference drugs except rifampin. This comprehensive theoretical analysis positions ligand 8 as a promising candidate for anti‐tuberculosis drug development, underscoring the need for further exploration through in vitro and in vivo studies. [ABSTRACT FROM AUTHOR]

Phytochemicals are now increasingly exploited as remedial agents for the management of diabetes due to side effects attributable to commercial antidiabetic agents. This study investigated the structural and molecular mechanisms by which betulinic acid exhibits its antidiabetic effect via in vitro and computational techniques. In vitro antidiabetic potential was analysed via on α-amylase, α-glucosidase, pancreatic lipase and α-chymotrypsin inhibitory assays. Its structural and molecular inhibitory mechanisms were investigated using Density Functional Theory (DFT) analysis, molecular docking and molecular dynamics (MD) simulation. Betulinic acid significantly (p < 0.05) inhibited α-amylase, α-glucosidase, pancreatic lipase and α-chymotrypsin enzymes with IC50 of 70.02 μg/mL, 0.27 μg/mL, 1.70 μg/mL and 8.44 μg/mL, respectively. According to DFT studies, betulinic acid possesses similar reaction in gaseous phase and water due to close values observed for highest occupied molecular orbital (HOMO) and lowest occupied molecular orbital (LUMO) and the chemical descriptors. The dipole moment indicates that betulinic acid has high polarity. Molecular electrostatic potential surface revealed the electrophilic and nucleophilic attack-prone atoms of the molecule. Molecular dynamic studies revealed a stable complex between betulinic acid and α-amylase, α-glucosidase, pancreatic lipase and α-chymotrypsin. The study elucidated the potent antidiabetic properties of betulinic acid by revealing its conformational inhibitory mode of action on enzymes involved in the onset of diabetes. [ABSTRACT FROM AUTHOR]

Nanodiamonds (NDs) are unique carbonaceous materials with exceptionally high stability, hardness, and notable electronic properties. Their applications in photocatalysis, biomedicine, and energy materials are usually carried out in aqueous environments, where they interact with aqueous adsorbates. Especially, electron density may rearrange from the diamond material toward oxidative adsorbates such as oxygen, which is known as charge transfer doping. In this article, we quantify the charge transfer doping for NDs with inhomogeneous surface coverings (hydroxyl, fluorine, and amorphous carbon), as well as NDs doped with heteroatoms (B, Si, N) using hybrid density functional theory (DFT) calculations. The transfer doping magnitude is largely determined by the NDs' highest occupied molecular orbital energies, which can in turn be modified by the surface covering and doping. However, local modifications of the ND structures do not have any local effects on the magnitude of the charge transfer. We furthermore analyze the impact of aqueous adsorbates on the excited states of an aqueous ND in the context of photocatalysis via time‐dependent DFT. Here, we find that the excited electrons are biased to move in the direction of the respective oxidative adsorbate. Surprisingly, we find that also unreactive species such as nitrous oxide may attract the excited electrons, which is probably due to the positive partial charge that is induced by the local N2O solvation geometry. [ABSTRACT FROM AUTHOR]

2-(3-Bromophenyl)-1-(4-morpholinyl)ethanone belongs to one of morpholine derivatives. In this paper, 2-(3-bromophenyl)-1-(4-morpholinyl)ethanone was synthesized by a two-step synthesis method. In order to determine the structure of the target compound, FT-IR,1H NMR,13C NMR and MS were used for detection. Meanwhile, X-ray diffraction was used to detect the single crystal and obtain the crystal structure data of the target compound. The molecular crystal structure was compared with that determined by density functional theory. The frontier molecular orbitals and molecular electrostatic potential energy were used to further study the physical properties of the compounds. [ABSTRACT FROM AUTHOR]

Triboelectrification is a ubiquitous and poorly understood phenomenon in powder processing, particularly for pharmaceutical powders. Charged particles can adhere to vessel walls, causing sheeting; they can also cause agglomeration, threatening the stability of powder formulations, and in extreme cases electrostatic discharges, which present a serious fire and explosion hazard. Triboelectrification is highly sensitive to environmental and material conditions, which makes it very difficult to compare experimental results from different publications. In this work, density functional theory (DFT) is used to investigate the charge transfer characteristics of several functional groups of paracetamol in order to better understand the mechanisms of charging at the nanoscale and the influence of the environmental and material properties on charge transfer. This is achieved by studying the structure and electronic properties at the molecule–substrate interface. Using this molecule–substrate approach, the charging contributions of individual functional groups are explored by examining the Hirschfeld charges, the charge density difference between the molecule and substrate, the density of states, and the location of the frontier orbitals (HOMO and LUMO) of a paracetamol molecule. Charge density difference calculations indicate a significant transfer of charge from the molecule to the surface. Observable regions of electron density enrichment and depletion are evident around the electron-donating and -withdrawing groups, respectively. The density of states for the paracetamol molecule evolves as it approaches the surface, and the band gap disappears upon contact with the substrate. Hirshfeld charge analysis reveals asymmetry in the charge redistribution around the molecule, highlighting the varying charging tendencies of different atoms. [ABSTRACT FROM AUTHOR]

Ethyl benzimidate and 4-phenyl-1,3,5-triazin-2-amine are important intermediates for the synthesis of triazine compounds. The structure of the target compounds were confirmed using 1H NMR, 13C NMR, mass spectrometry, and FT-IR spectroscopy. The precise structure of ethyl benzimidate and 4-phenyl-1,3,5-triazin-2-amine were analyzed using single-crystal X-ray diffraction. The molecular structures were further calculated using density functional theory (DFT), which were compared with the X-ray diffraction value. The results of the conformational analysis indicate that the molecular structures optimized by DFT were consistent with the crystal structures determined by single crystal X-ray diffraction. In addition, the molecular electrostatic potential and frontier molecular orbitals of the title compounds were further investigated by DFT, and some physicochemical properties of the compounds are revealed. [ABSTRACT FROM AUTHOR]

The high reactivity of the acetylene group enables the formation of strong chemical bonds with active sites on mineral surfaces, thereby improving the flotation performance of gold minerals. This study utilized density functional theory (DFT) to analyze the quantum chemical parameters of structure, Mulliken population, and the frontier orbitals of a thioester collector containing an acetylene group, PDEC (prop-2-yn-1-yl diethylcarbamodithioate). PDEC was compared with analogous thioester collectors Z-200 and Al-DECDT. The interaction mechanism of PDEC on the Au(1 1 1) surface was simulated, followed by empirical validation through adsorption experiments. The findings indicate that the S atom of PDEC in the carbon–sulfur group exhibits shorter covalent bond lengths, and has reduced carbon–sulfur double bonds and Mulliken population, resulting in enhanced electron localization. This confers greater selectivity to PDEC during its adsorption on mineral surfaces. Frontier orbital analysis shows that the electrons of the acetylene group possess a notable electron-accepting capacity, significantly influencing the frontier orbital energy of PDEC and playing a pivotal role in the bonding interaction with mineral surfaces. Both the S atom in the carbon–sulfur group and its acetylene group establish stable adsorption structures with the A(111) surface in a single coordination mode. The adsorption energy sequence is PDEC > Al-DECDT > Z-200. Partial density of states demonstrates that the S 3p orbit of the carbon–sulfur group hybridizes with the Au 5d orbit, while the C 2p orbit of the acetylene group engages in weaker back-donation bonding with the Au 5d orbit. This is corroborated by the electron density difference and post-adsorption Mulliken population analyses, revealing that the S atom of the carbon–sulfur group in PDEC donates electrons to the Au atom, forming dominant positive coordination bonds, whereas the acetylene group accepts partial electrons from the Au atom, resulting in weaker back-donation bonds. The adsorption experiments align with the DFT adsorption energy results. [ABSTRACT FROM AUTHOR]

Fractionation of the stem bark of Enantia chlorantha Oliv yields three alkaloids, palmatine (1), jatrorrhizine (2), columbamine (3), and β-Sitosterol (4). In this investigation, density functional theory (DFT) calculations were carried out to evaluate the electronic structure and properties of 1–4 by DFT-B3LYP/6-31G level of theory using Gaussian 09 software. The highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), HOMO-LUMO energy difference (band gap), hardness (η), softness (S), dipole moment (μ), electronegativity (χ), hydrophobicity (logP), topological surface area (TPSA), and energy gap (Eg) were calculated. The in vitro cytotoxicity of the compounds was investigated against MCF-7 and HCT116 cancer cell lines using Wi-38 cells as a control. The compounds inhibited the proliferation of the MCF-7 and HCT116 cell lines and induced apoptosis via upregulation of caspase-3, Bax, PARP cleavage, and downregulation of Bcl-2. DFT analyses revealed that compounds 1 and 3 have smaller energy gaps, 0.072 and 0.071eV, respectively, with the highest dipole moments; hence, these compounds are more chemically reactive and exhibit better modulation of caspase-3 enzyme and inhibitory activities of the MCF-3 and HCT116 cell lines. The antimicrobial and antiparasitic evaluation of 1–4 showed moderate efficacy against the bacterial strains and moderate antiparasitic activity against Cichlidogyrus tilapia. [ABSTRACT FROM AUTHOR]

The 2D network having porphyrin like internal core are well established in literature due to their remarkable molecular tunability, photophysical and optoelectronics properties. Therefore, in the quest to attain the high performance nonlinear optical (NLO) response we have designed single Benzo‐bisimidazole (BIZ) unit which has porphyrin like motif and expanded it strategically in such a way that it forms cage and further it convert into 2D nanosheet. Density functional theory (DFT), sum‐over‐state models and time dependent‐DFT (TD‐DFT) simulation were performed for geometric and electronic properties calculation. Expanding the BIZ plays a pivotal role in enhancement of the first static hyperpolarizability (βtot) from 205.65 to 13754.59 au. Further, alkali metals substitution leads to gigantic enhancement of βtot value from 2200.17 to 636673.60 au which is enormously higher than that of recently reported porphyrin derivative (47950 au). Calculated results revealed that the gap between highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) become narrow down from 6.28 eV (1) to 1.70 eV (6). It is to note that the designed molecules exhibit red shift of absorption. Further, density of states (DOS), and transition density matrix (TDM) analysis have also performed to explore the charge transfer and structure property relationship. [ABSTRACT FROM AUTHOR]

The molecular structure of 1-(4-hydroxy-3-methoxyphenyl) ethenone has been optimized, and its various parameters were ascertained, using Density Functional Theory. The molecule's Fourier Transform-Infra Red and Raman spectra are recorded and examined. By comparing the computational and experimental results, molecular structure, bond length, and vibrational band intensity were all interpreted. The Integral Equation Formalism polarizable continuum model's depictions of electronic and Frontier Molecular Orbital solvent interaction investigations are sported to perceive the charge transfer among the atoms of the molecule in eco-green solvents such as water, acetone, and ethanol. The reactivity sites can be studied by locating and charting the electron density on the surface. The compound's hardness, softness, electrophilicity, and ionization potential were all analyzed. The pharmacological effects and intra-molecular hyper conjugative interactions are liable for its molecular stability, as shown by Natural Bond Orbital research. Topological studies, including Electron Localized Function, Localized Orbital Locator, and Reduced density gradient analysis, were performed to locate the compound's bonding area and Vander Waals interactions. Urea was used as a reference compound to examine the substance's non-linear optical characteristics. Total Density of States has investigated the role of molecular orbitals. Drug-likeness, a Ramachandran plot, and molecular docking were also performed to further analyze 1-(4-hydroxy-3-methoxyphenyl) ethanone's biological activity. The docking results lend credence to the idea that the title compound could function as a powerful cancer treatment. [ABSTRACT FROM AUTHOR]

An investigation based on synthesis of 6‐arylated‐pyridine‐3‐yl)methanol derivatives: 6‐(2‐benzofuranyl)pyridin‐3‐yl)methanol (BFPM), (6‐([biphenyl]‐4‐yl)3‐pyridinyl methanol (BPPM), 6‐(3‐Flourophenyl)‐4‐pyridine‐methanol (FPPM), and 6‐(4‐Chlorophenyl)‐4‐pyridine‐methanol (CPPM) compounds is presented in this study. Furthermore, a comparison of experimental spectroscopic data (NMR, FTIR, UV‐Vis), structural factors, nonlinear optical characteristics with theoretical frontier molecular orbital analysis, natural population analysis, natural bond orbitals analysis of pyridine derivatives is drawn using density functional theory (DFT) and time‐dependent density functional theory (TD‐DFT) at the B3LYP/6‐311+G (2d,p) level of theory was used. Therefore, the DFT‐based findings and experimental data were in perfect accord. By using NBO analysis, it has been possible to understand how charge delocalization and HP interactions contribute to molecule stability. Moreover, the FMO energy levels were used to calculate global reaction characteristics, which showed that FPPM with the highest ▵ELUMO – HOMO of 4.91 eV, was less reactive and more stable than BFPM, BPPM, and CPPM. Compared to the prototype compound, NLO studies revealed that BFPM, BPPM, FPPM, and FPPM exhibit better characteristics, revealing their potential for use in photoelectric technology. [ABSTRACT FROM AUTHOR]

SF6/N2 mixture is an alternative gas of SF6, which is already used in electrical equipment. When a malfunction occurs, SF6/N2 will decompose and further react with trace water and oxygen to produce nitrogen-containing gases such as NO, NO2, N2O and NF3. It is necessary to monitor these gases to ensure the safe operation of the equipment. This paper is based on density functional theory (DFT), the nanomaterial Ti3C2T x doped with Au atom was selected as sensing material. The result shows that Au/Ti3C2T x has larger adsorption energy when NO and NO2 adsorbed on the surface, the stable structures were conformed more easily with NO and NO2 compared with N2O and NF3. The density of states analysis and the frontier molecule orbital analysis reveal more change of the system before and after NO and NO2 adsorption, suggesting the material showed good sensitivity performance to NO and NO2. Thus, Au/Ti3C2T x is considered to have the potential for sensing NO and NO2. [ABSTRACT FROM AUTHOR]

(E)-N2,N2-dimethyl-6-styryl-1,3,5-triazine-2,4-diamine and (E)-N-(4-(dimethylamino)-6-styryl-1,3,5-triazin-2-yl) acetamide are important intermediates for the synthesis of triazine compounds. The structure of the target compounds were confirmed using 1H NMR, 13C NMR, HRMS and FT-IR spectroscopy. The precise structure of (E)-N2,N2-dimethyl-6-styryl-1,3,5-triazine-2,4-diamine and (E)-N-(4-(dimethylamino)-6-styryl-1,3,5-triazin-2-yl) acetamide were analyzed using single-crystal X-ray diffraction. The molecular structures were further calculated using density functional theory (DFT), which were compared with the X-ray diffraction value. The results of the conformational analysis indicate that the molecular structures optimized by DFT were consistent with the crystal structures determined by single crystal X-ray diffraction. In addition, the molecular electrostatic potential and frontier molecular orbitals of the title compounds were further investigated by DFT, and some physicochemical properties of the compounds are revealed. [ABSTRACT FROM AUTHOR]

Due to their widespread availability and lower costs Na-ion batteries have grabbed attention as a promising substitute for lithium-ion batteries. In this paper, we delve into a computational investigation of the potential use of 2,4-Chloronitrotoluene and pyrazine as electrode materials for SIBs. We utilized Density Functional Theory (DFT) calculations to examine their properties and suitability for energy storage applications. Adsorption energies, highest occupied molecular orbital, lowest unoccupied molecular orbital, HLG energies, total energies, and bond lengths were computed using computational theories for aromatic compounds. This computation is based here on the DFT and computational engineering modelling approach. The results indicate that both 2,4-chloronitrotoluene and pyrazine exhibit favorable adsorption energies for Na-ion adsorption, indicating their potential as electrode materials. Furthermore, the investigation delved into the electronic properties of the materials. Notably, the analysis showed that the EHOMO, ELUMO, and EHLG are facilitative to the efficient transfer of electrons during the operation of the battery. Moreover, the computed bond lengths indicate that stable Na-ion adsorption can appear on both materials, further solidifying their potential for integration into the framework of Na-ion batteries. In essence, this study yields valuable insights into the electrochemical aspects of 2,4-chloronitrotoluene and pyrazine, highlighting their promising candidacy as electrode materials for SIBs. [ABSTRACT FROM AUTHOR]

Context: Bis(terpyridine)manganese(III) exhibits Jahn–Teller distortion due to the inequivalent occupation of the degenerate eg orbitals of this high-spin d4 pseudo octahedral complex. Due to the spatially constrained nature of the terpyridine ligand, the central Mn-N bonds will always be shorter than the Mn-N terminal bonds, making it more difficult to distinguish between compression and elongation Jahn–Teller structures for bis(terpyridine)manganese(III). Density functional theory (DFT) calculations were utilized as a tool to evaluate the type of Jahn–Teller distortion in the high-spin d4 bis(terpyridine)manganese(III). The nature of the Jahn–Teller distortion calculated does depend upon the choice of density functional approximation (DFA) with the B3LYP, M06, and OLYP-D3 DFAs giving compression and the PW6B95D3, MN15, and MN15-D3 DFAs giving elongation in gas-phase calculations. All solvent-phase calculations yield an elongated structure for the bis(terpyridine)manganese(III) compound, which is yet to be structurally characterized experimentally. However, both gas and solvent OLYP-D3 calculations result in a compressed structure for the only experimentally isolated and characterized bis(terpyridine)manganese(III) complex, specifically the complex with terpyridine = 4′-(4-methylphenyl)-2,2′:6′,2′′-terpyridine. This alignment with the experimentally observed compression Jahn–Teller structure enhances the credibility of OLYP-D3 calculations in reproducing the observed geometries. The compressed Jahn–Teller geometries were near D2d symmetry with the z-axis for compression defined along the Mn-N central bonds. Elongation Jahn–Teller distortion is not possible along the Mn-N central bonds, due to their spatially constrained nature. Thus, elongation occur along one pair of opposite Mn-N terminal bonds that are longer than the other pair of opposite terminal bonds, with shorter central bonds. The highest symmetry of the elongation Jahn–Teller distortion geometry of bis(terpyridine)manganese(III) is C2v. Criteria to distinguish between a compression and elongation Jahn–Teller geometry for bis(terpyridine)manganese(III) are identified. The nature of the singly occupied eg molecular orbital, exhibiting anti-bonding interaction with the nitrogen-p MOs involved, dictates the type of Jahn–Teller distortion that occurs. The low-energy occupied bonding t2g molecular orbitals establish bonds with and undergo mixing with the ligand molecular orbitals. The OLYP-D3 functional is recommended for calculating bis(terpyridine)manganese(III) and related compounds due to its consistent generation of metal–ligand bonds slightly longer than observed in experiments, in line with the required behavior. Additionally, OLYP-D3 offers a realistic electronic structure for Jahn–Teller distorted bis(terpyridine)manganese(III), correctly identifying alpha eg molecular orbitals as the highest occupied molecular orbital and lowest unoccupied molecular orbital in agreement with experimental electrochemical studies. Furthermore, OLYP-D3 accurately reproduces the experimental compression geometry for the only structurally known bis(terpyridine)manganese(III) compound, instilling confidence in its reliability for such calculations. Methods: DFT geometry optimization and frequency calculations were done on the two different modes of Jahn–Teller distortion of bis(terpyridine)manganese(III), using the OLYP, B3LYP, M06, PW6B95D3, and MN15 functionals, with and without the Grimme's D3 dispersion correction, and the 6-311G(d,p) or def2TZVPP basis set, as implemented in Gaussian 16. All optimizations were in the gas phase and also in the solvent phase with CH3CN as implicit solvent using IEFPCM. DFT calculations were utilized to determine the Jahn–Teller effect on the geometry of high-spin d4 bis(terpyridine)manganese(III) complex containing two structurally constrained tridentate ligands. [ABSTRACT FROM AUTHOR]

In this study, tert-butyl 4-(5-bromopyridin-2-yloxy)piperidine-1-carboxylate was synthesized. The title compound was characterized using ¹H NMR, 13C NMR, MS, and FT-IR techniques, and its single crystal was evaluated using X-ray diffraction (XRD). The molecular structure was optimized using the density functional theory (DFT) at the B3LYP/6-311+G(2d, p) level. The optimized structure was also compared with the crystal structure determined using single-crystal (XRD), and the results were consistent. Molecular electrostatic potential (MEP) and frontier molecular orbital (FMOs) analyses of the title compound were preformed using computational methods. Infrared vibrational analysis of the target compound was also conducted. [ABSTRACT FROM AUTHOR]

In this study, for the first time, boron oxide nanoflake is analyzed as drug carrier for favipiravir using computational studies. The thermodynamic stability of the boron oxide and favipiravir justifies the strong interaction between both species. Four orientations are investigated for the interaction between the favipiravir and the B3O3 nanoflake. The Eint of the most stable orientation is −26.98 kcal/mol, whereas the counterpoise-corrected energy is −22.59 kcal/mol. Noncovalent interaction index (NCI) and quantum theory of atoms in molecules (QTAIM) analyses are performed to obtain insights about the behavior and the types of interactions that occur between B3O3 nanoflake and favipiravir. The results indicate the presence of hydrogen bonding between the hydrogen in the favipiravir and the oxygen in the B3O3 nanoflake in the most stable complex (FAV@B3O3-C1). The electronic properties are investigated through frontier molecular orbital analysis, dipole moments and chemical reactivity descriptors. These parameters showed the significant activity of B3O3 for favipiravir. NBO charge analysis transfer illustrated the charge transfer between the two species, and UV-VIS analysis confirmed the electronic excitation. Our work suggested a suitable drug carrier system for the antiviral drug favipiravir, which can be considered by the experimentalist for better drug delivery systems. [ABSTRACT FROM AUTHOR]

In this study, tert-butyl 4-(5-bromopyridin-2-yloxy)piperidine-1-carboxylate was synthesized. The title compound was characterized using ¹H NMR, 13C NMR, MS, and FT-IR techniques, and its single crystal was evaluated using X-ray diffraction (XRD). The molecular structure was optimized using the density functional theory (DFT) at the B3LYP/6-311 + G(2d, p) level. The optimized structure was also compared with the crystal structure determined using single-crystal (XRD), and the results were consistent. Molecular electrostatic potential (MEP) and frontier molecular orbital (FMOs) analyses of the title compound were preformed using computational methods. Infrared vibrational analysis of the target compound was also conducted. [ABSTRACT FROM AUTHOR]

In the current work, we have investigated the charge transport and Non-Linear Optical (NLO) characteristics of oxa[n]circulenes. Density functional theory (DFT) and Time dependent density functional theory (TD-DFT) are used to examine optoelectronic and NLO characteristics. TD-DFT calculations are utilized to simulate the absorption energies. Ionization potential (I.P.), electron affinity (E.A.), the frontier molecular orbitals (FMOs) i.e., Highest occupied molecular orbital (HOMO), Lowest unoccupied molecular orbital (LUMO) and HOMO-LUMO gap (Ege) are calculated for the reported molecules. Nuclear independent chemical shift (NICS) values are generated to find aromatic behavior and stability of oxa[n]circulenes. Along with first and second hyperpolarizabilities, optoelectronic properties are also reported for the designed compounds. [ABSTRACT FROM AUTHOR]

A novel single crystal of (3-(4-chlorophenyl)-4,5-dihydroisoxazol-5-yl)methyl benzenesulfonate has been synthetized via a one-pot sequential strategy under sonication. The single crystal has been investigated using X-ray diffraction analysis. Hydrogen bonding between C–H···O and C–H···N produces a layer structure in the crystal. According to a Hirshfeld surface analysis, interactions H···H (28.9%), H···O/O···H (26.7%) and H···C/C···H (15.8%) make the largest contributions to crystal packing. The optimized structure and the solid-state structure that was obtained through experiments are compared using density functional theory at the B3LYP/6-311 G + (d,p) level. The computed energy difference between the lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) is 4.6548 eV. [ABSTRACT FROM AUTHOR]

4-((furan-2-ylmethyl)amino)benzoic acid and N'-acryloyl-N'-phenylfuran-2-carbohydrazide are important intermediates for the synthesis of furan compounds with furan ring. In this paper, the title compounds were obtained by two-step reaction respectively. The structures of the title compounds were confirmed by FTIR, 1H and 13C NMR spectroscopy, and mass spectrometry. At the same time, single crystals of the title compounds were measured by X-ray diffraction and subjected to crystallographic and conformational analyses. The molecular structures were further calculated using density functional theory (DFT), which were compared with the X-ray diffraction value. The results of the conformational analysis indicate that the molecular structures optimized by DFT were consistent with the crystal structures determined by single crystal X-ray diffraction. In addition, the molecular electrostatic potential and frontier molecular orbitals of the title compounds are further investigated by DFT, and some physicochemical properties of the compounds are revealed. [ABSTRACT FROM AUTHOR]

Context: Understanding the photochemistry of boron nitrogen (BN)-containing compounds is an important aspect to enhance the various optical and electronic applications. In this work, we have explored the structure, bonding, reactivity, electronic absorption (UV–Vis), and light harvesting efficiency (LHE) of a series of BN3 ring and open-chain systems. The frontier molecular orbitals (FMO) analysis found that ring systems have a low HOMO–LUMO energy gap as compared to the open-chain systems which insinuates the feasibility of ring systems in the optoelectronic materials. Also, the molecular electrostatic potential (MEP) maps have been computed to pursue the electrophilic and nucleophilic sites available at the surface of the compound. Interestingly, we have found that the open-chain compounds show more molecular charge distribution range rather than the ring compounds. The investigation of photophysical properties showed that the UV–Vis absorption significantly red-shifted in BN3 ring systems as compared to open-chain counterparts. Furthermore, light harvesting efficiency (LHE) was also found higher in the ring systems as compared to the BN3 open-chain systems. Moreover, the computed structural parameters are found well corroborated with the available X-ray data. Methods: Structures of all compounds were optimized by using density functional theory (DFT) method, with M06-2X/6-31G(d,p) level. All the calculations in this work are carried out in Gaussian 16 program package. GaussView6.1 software was used for the modeling of initial geometries and for the plotting of MEP plots. To account the solvent effect on geometries the polarized continuum model (PCM) was used and tetrahydrofuran (THF) taken as solvent. The NBO6.0 program (incorporated in G16 software) was used for the exploration of bonding nature and stabilization energies of B-N bond. The absorption spectra were simulated by using ORCA 4.2 program. [ABSTRACT FROM AUTHOR]

In this work, we have investigated the complex formation capability of gemcitabine drug with host cucurbit[n]urils, Q[n] (n = 6, 7, and 8) using density functional theory (DFT). The DFT studies demonstrate that the most stable configuration is a fully encapsulated complex. In the encapsulated gemcitabine@Q[6] and gemcitabine@Q[7] complexes, the gemcitabine amino -NH2 and the alcoholic groups bond with the carbonyl units of Q[n]. The addition of sodium ions leads to the partial exclusion of the gemcitabine molecule and the sodium atoms lie close to the carbonyl portal of Q[7]. Thermodynamic parameters computed for the complexation process exhibit high negative Gibbs free energy change, implying that the encapsulation process is spontaneous and is an enthalpy-driven process. Frontier molecular orbitals are located mainly on the gemcitabine uracil ring, before and after encapsulation, indicating that the encapsulation occurs by pure physical adsorption. Quantitative molecular electrostatic potentials demonstrate a shift in electron density during the complex formation and are more pronounced in gemcitabine@Q[7]. Atoms-in-molecule (AIM) topological analysis illustrate that these complexes are stabilized by various non-covalent interactions including hydrogen bonding (HBs) and C···F interactions. The reduced density gradient (RDG) graph exhibits the presence of strong HBs and weak van der Waals interactions and the presence of steric repulsion. The isosurface non-covalent interactions (NCI) diagram shows predominant steric interaction in the gemcitabine@Q[6] complex. The NCI isosurface for gemcitabine encapsulated complexes with Q[7] and Q[8] host displays that the green patches are uniformly distributed in all directions. Finally, EDA results demonstrate Pauling's repulsive energy is predominant in gemcitabine@Q[6] complex, while the orbital and dispersion energies stabilize the gemcitabine@Q[7] complex. [ABSTRACT FROM AUTHOR]

A series of ten new hydrazide–hydrazone derivatives bearing a pyrrole ring were synthesized and structurally elucidated through appropriate spectral characteristics. The target hydrazones were assessed for radical scavenging activity through 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) tests, with ethyl 5-(4-bromophenyl)-1-(2-(2-(4-hydroxy-3,5-dimethoxybenzylidene)hydrazine-yl)-2-oxoethyl)-2-methyl-1H-pyrrole-3-carboxylate (7d) and ethyl 5-(4-bromophenyl)-1-(3-(2-(4-hydroxy-3,5-dimethoxybenzylidene) hydra zine-yl)-3-oxopropyl)-2-methyl-1H-pyrrole-3-carboxylate (8d) highlighted as the best radical scavengers from the series. Additional density functional theory (DFT) studies have indicated that the best radical scavenging ligands in the newly synthesized molecules are stable, do not decompose into elements, are less polarizable, and with a hard nature. The energy of the highest occupied molecular orbital (HOMO) revealed that both compounds possess good electron donation capacities. Overall, 7d and 8d can readily scavenge free radicals in biological systems via the donation of hydrogen atoms and single electron transfer. The performed in vitro assessment of the compound's protective activity on the H2O2-induced oxidative stress model on human neuroblastoma cell line SH-SY5Y determined 7d as the most perspective representative with the lowest cellular toxicity and the highest protection. [ABSTRACT FROM AUTHOR]

In this work, a new compound, 2-(N-allylsulfamoyl)-N-propylbenzamide, has been synthesized via a tandem one-pot reaction under sonication. The rotational orientations of the allylsulfamoyl and the amide groups in the title molecule, C13H18N2O3S, are partly determined by an intramolecular N—H···O hydrogen bond. In the crystal, a layer structure is generated by N—H···O and C—H···O hydrogen bonds plus C—H···π (ring) interactions. A Hirshfeld surface analysis indicates that the most important contributions to crystal packing are from H···H (59.2%), H···O/O···H (23.5%), and H···C/C···H (14.6%) interactions. The optimized structure calculated using density functional theory at the B3LYP/6–311 G (d,p) level is compared with the experimentally determined structure in the solid state. The calculated highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy gap is 5.3828 eV. [ABSTRACT FROM AUTHOR]

The main objective of the study is to analyze the structural behavior and non-linear optical activity of 1, 2-diphenyl-2-methoxyethanone oxime (DMEO) by theoretical spectroscopic techniques. Theoretical vibrational spectra of the title compound were interpreted by means of potential energy distributions (PEDs) using the MOLVIB program. The UV-Visible spectrum of DMEO in ethanol was simulated using the time-dependent density functional theory calculations. Molecular electron density, topology and natural bond orbital (NBO) analysis were used to explain the strength of interaction. The frontier molecular orbital energies, the HOMO-LUMO gap, and the global reactivity descriptors of the title compound are determined. Molecular electrostatic potential (MEP) is stimulated for identifying the better reactive sites for electrophilic and nucleophilic attacks. The first and second order hyperpolarizability of the title compounds has been exhibited using the computational methods to investigate the non-linear optical (NLO) response and inter/intra-molecular charge transfer mechanism of the mentioned compound. The molecular docking studies were performed to investigate the binding affinity of legend with target receptor. [ABSTRACT FROM AUTHOR]

By using density functional theory (DFT), the FT-Raman, FT-IR, and UV–visible spectra of 1-amino-4-(4-hydroxyphenyl) piperazine (1AM4HPP), 1-chloro-4-(4-hydroxyphenyl) piperazine (1CL4HPP), and 1-methyl-4-(4-hydroxyphenyl) piperazine (1ME4HPP) are carried out. The comparative donor and acceptor interactions are studied for all title compounds using the NBO method. The charge transfer, chemical parameters, and biological activities are examined by highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy results. By density functional theory NLO properties of 1AM4HPP, 1CL4HPP, and 1ME4HPP are studied. The qualitative information of the molecules is carried out using molecular electrostatic potential (MEP) studies. The thermodynamic properties like entropy (S), enthalpy (H), and heat capacity (Cp) are estimated at various temperatures. For each compound, molecular docking is carried out with suitable proteins. [ABSTRACT FROM AUTHOR]

Four novel organoimido‐substituted hexamolybdate dyes featuring acridine/anthracene donors for dye‐sensitized solar cells (DSSCs) have been designed and studied using a combination of density functional theory (DFT) and time‐dependent density functional theory (TDDFT) calculations. The energy levels of frontier molecular orbitals, absorption spectra with electronic transition characters, and photovoltaic parameters of dyes 1–4 were systematically evaluated. The results confirm the suitability of all the studied dyes for n‐type DSSCs. The investigated dyes could be introduced as an active co‐absorbent as well as main dye. All dyes showed remarkable reorganization energy for electron transport (λe) and hence increased electron transfer rate. Due to the strong absorption in the visible region, as well as high light harvesting efficiency (LHE), dye regeneration efficiency (DRE), and electron injection efficiency (Φinj), dyes 2 and 3 are the most promising candidates for high performance DSSC materials. [ABSTRACT FROM AUTHOR]

Carbohydrates are plentiful naturally occurring macromolecules that are crucial to a range of biological activities. Therefore, the focus of our research group has been on computational studies of previously synthesized methyl a-D-glucopyranoside (a-MGP) derivatives. To determine the chemical descriptors of the synthesized compounds, quantum chemical research was conducted using Gaussian09 and the DFT (density functional theory) calculations. Frontier molecular orbital features, electrostatics potential, and thermodynamic properties of these optimized compounds are investigated. PASS (prediction of activity spectra for substances) showed the excellent thermodynamic and antimicrobial properties of the designed a-MGP derivatives. The binding energy and binding strategies of certain bacterial proteins from Pseudomonas aeruginosa (3PBN, and 3PBS) were investigated using molecular docking simulations, and adequate binding affinity was reported. QSAR (quantitative structure-activity correlations) analysis found a better drug-likeness profile for all a-MGP derivatives, and pharmacokinetic prediction demonstrated an enhanced drug-likeness profile of a-MGP derivatives. Furthermore, by side chain alteration in the a-D-glucopyranoside sequence, these compounds can be thought of as strong antibacterial agents. [ABSTRACT FROM AUTHOR]

The density functional theory and vibrational spectroscopy investigation were carried out on 6-Fluoro-4-oxo-3,4-dihydro-2H-chromene-2-carboxylic acid (FODHCC). The optimized structure, vibrational frequencies, and other chemical parameters are obtained using the B3LYP method with a 6-311++G(d,p) basis set. FT-IR studies are used to identify the various functional groups, which are then compared with simulated spectra. Atoms In Molecules (AIM) studies are carried out to know the bonding nature. NBO analysis is used to investigate the interactions between donors and acceptors. The stability, hardness, and softness are studied by Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO). The molecular electrostatic potential (MEP) is used to determine the molecule's reactive regions. The maximum absorption wavelength is determined using the UV-Vis spectrum and compared with the simulated spectrum created using TD-DFT/CAM technique with various solvents. The NLO studies were carried out on the molecule to know the dipole moment and other NLO parameters. The molecule is utilized in biological studies such as molecular docking and drug similarity. [ABSTRACT FROM AUTHOR]

The single crystal of syringic acid was crystallized by slow evaporation technique and characterized using XRD, FTIR, FT-Raman, and UV-Vis spectroscopy. XRD confirms the crystalline structure as centrosymmetric monoclinic with C2/c space group. The functional groups identified by FTIR and FT Raman studies and by UV-Vis give the cut off wavelength as 276 nm. Quantum chemical calculations were performed using density functional theory. The computed and experimental vibrational wavenumbers were assigned and compared. Frontier molecular orbital research reveals the reactivity and kinetic stability of the molecule. The molecule's reactive site is further confirmed by the Mulliken atomic charge distribution and molecular electrostatic potential surface analysis. The molecule's absorption spectra were computed in the liquid phase (ethanol), by TD-DFT with the same basic set, which established a π to π* electronic transition and was comparable to the observed UV-Vis spectrum. The Hirshfeld analysis was used to determine the effectiveness of interactions between distinct atoms as well as their contribution. The O...H and H...H contributions are highest due to the intermolecular hydrogen bonding. The natural bond orbital analysis demonstrates the molecule's bioactivity. The biological activity such as anti-bacterial, antioxidant and anti-cancer has been evaluated through disk diffusion, DDPH assay and molecular docking method. The zone of inhibition was clearly observed on gram-positive and gram-negative bacterium that showed the anti-bacterial property of syringic acid. The syringic acid prevents breast cancer, according to molecular docking research. Seven different types of breast cancer proteins based on different mechanisms were utilized to test the syringic acid molecule's docking efficiency, and it was revealed that PR and HER-2 have the highest docking scores with −7.7Kcal/mol. In addition, to better understand the safety profile of syringic acid, physicochemical and pharmacokinetic properties were investigated. [ABSTRACT FROM AUTHOR]

Context: The design and synthesis of safe and highly active sulfonylurea herbicides is still a challenge. Therefore, following some principles of structure-activity relationship (SAR) of sulfonylurea herbicides, this work focuses on evaluating two sulfonylurea derivatives bearing electron-withdrawing substituents, namely, –(CO)OCH3 and –NO2 on the aryl group, on herbicidal activity. To understand the effects caused by the substituent groups, the molecular and electronic structures of the sulfonylureas were evaluated by density functional theory. Likewise, the crystalline supramolecular arrangements of both compounds were analyzed by Hirshfeld surface, QTAIM, and NBO, with the aim of verifying changes in intermolecular interactions caused by substituent groups. Finally, through a toxicophoric analysis, we were able to predict the interacting groups in their biological target, acetolactate synthase, and verify the interactions with the binding site. Methods: All theoretical calculations were conducted using the highly parameterized empirical exchange-correlation functional M06-2X accompanied by the diffuse and polarized basis set 6-311++G(d,p). The atomic coordinates were obtained directly from the crystalline structures, and from the energies of the frontier molecular orbitals (HOMO and LUMO), chemical descriptors were obtained that indicated the influence of the functional groups in the sulfonylureas on the reactivity of the molecules. The intermolecular interactions in the crystals were analyzed using the Hirshfeld, QTAIM, and NBO surfaces. Toxicophoric modeling was performed by the PharmaGist webserver and molecular docking calculations were performed by the GOLD 2022.1.0 software package so that the ligand was fitted to the binding site in a 10 Å sphere. For this, genetic algorithm parameters were used using the ChemPLP scoring function for docking and ASP for redocking. [ABSTRACT FROM AUTHOR]

The potentiality of the β12 borophene (β12) and pristine graphene (GN) nanosheets to adsorb tetrahalomethanes (CX4; X = F, Cl, and Br) were investigated using density functional theory (DFT) methods. To provide a thorough understanding of the adsorption process, tetrel (XC-X3∙∙∙β12/GN)- and halogen (X3C-X∙∙∙β12/GN)-oriented configurations were characterized at various adsorption sites. According to the energetic manifestations, the adsorption process of the CX4∙∙∙β12/GN complexes within the tetrel-oriented configuration led to more desirable negative adsorption energy (Eads) values than that within the halogen-oriented analogs. Numerically, Eads values of the CBr4∙∙∙Br1@β12 and T@GN complexes within tetrel-/halogen-oriented configurations were −12.33/−8.91 and −10.03/−6.00 kcal/mol, respectively. Frontier molecular orbital (FMO) results exhibited changes in the EHOMO, ELUMO, and Egap values of the pure β12 and GN nanosheets following the adsorption of CX4 molecules. Bader charge transfer findings outlined the electron-donating property for the CX4 molecules after adsorbing on the β12 and GN nanosheets within the two modeled configurations, except the adsorbed CBr4 molecule on the GN sheet within the tetrel-oriented configuration. Following the adsorption process, new bands and peaks were observed in the band structure and density of state (DOS) plots, respectively, with a larger number in the case of the tetrel-oriented configuration than in the halogen-oriented one. According to the solvent effect affirmations, adsorption energies of the CX4∙∙∙β12/GN complexes increased in the presence of a water medium. The results of this study will serve as a focal point for experimentalists to better comprehend the adsorption behavior of β12 and GN nanosheets toward small toxic molecules. [ABSTRACT FROM AUTHOR]

In this study, we investigated the electronic properties and selective adsorption for CO2 of nickel boride clusters (NiB)n, (n = 1~10) using the first principles method. We optimized the structures of the clusters and analyzed their stability based on binding energy per atom. It was observed that (NiB)n clusters adopt 3D geometries from n = 4, which were more stable compared to the plane clusters. The vertical electron affinity, vertical ionization energy, chemical potential, and highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) gap were calculated. Our results revealed that (NiB)6 and (NiB)10, with high chemical potential, exhibit a higher affinity for CO2 adsorption due to a charge delivery channel that forms along the Ni→B→CO2 path. Notably, (NiB)10 demonstrated a more practical CO2 desorption temperature, as well as a broader window for the selective adsorption of CO2 over N2. The density of states analysis showed that the enhanced CO2 adsorption on (NiB)10 can be attributed to the synergistic effect between Ni and B, which provides more active sites for CO2 adsorption and promotes the electron transfer from the surface to the CO2 molecule. Our theoretical results imply that (NiB)10 should be a promising candidate for CO2 capture. [ABSTRACT FROM AUTHOR]

1,1-Diisopropyl-3-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)urea was given by two-steps method, then the single crystal was measured by using X-ray diffraction. According to density functional theory (DFT) by using the 6-311 ± G (2d, p) basis set, the optimized structure of the molecule was calculated with the B3LYP method, then the calculated value was compared with the value of X-ray diffraction. The analysis of optimized conformation by DFT indicated that the crystal structure was consistent with single crystal by X-ray diffraction. Finally, DFT was used to study the molecular electrostatic potential and frontier molecular orbitals of the title compound, which revealed its physicochemical properties. [ABSTRACT FROM AUTHOR]

The structure of a triazole derivative, (E)-4-((furan-2-ylmethylene)amino)-3-methyl-1H-1,2,4-triazole-5(4H)-thione (4FAMTT), has been elucidated using spectroscopic and single crystal X-ray diffraction studies. The crystal structure is stabilized by N2--H2···S1 intermolecular interaction that leads to the formation of a dimer. The computational investigations using Density Functional Theory (DFT) have been performed to optimize the geometrical parameters which, by and large, agree with the X-ray data. The Frontier Molecular Orbitals (FMOs) have been studied to estimate the kinetic stability and reactivity of the molecule. The global reactivity descriptors and molecular electrostatic potential (MEP) may help identify the molecule's reactive locations for possible interactions. The Hirshfeld surface (HS) and 2D fingerprint plot analysis have been employed to investigate intercontacts in the crystal structure. The interaction energies that stabilize the crystal packing have been calculated and represented graphically. The molecular docking analysis indicates a high binding affinity of 4FAMTT for the COX-2 protein (PDB ID: 5KIR) and is able to bind its active site with a relatively strong interaction. [ABSTRACT FROM AUTHOR]

In this study, the target compound was synthesized from 6-(benzylthio)pyridine-3-amine. The single crystal of the title compound was identified by X-ray diffraction. The molecular structure was further calculated by the density functional theory (DFT) and compared with the X-ray data. The results of conformational analysis showed that the DFT-optimized molecular structure was consistent with the crystal structure determined by single-crystal X-ray diffraction. The molecular electrostatic potential and frontier molecular orbital of the title compound were further studied by the DFT. The molecular interactions and contacts were quantified using Hirshfeld surface analysis and two-dimensional fingerprint plots. [ABSTRACT FROM AUTHOR]

In this study, 6-chloro-1-isobutyl-3-methylpyrimidine-2,4(1H,3H)-dione was successfully synthesized and its structure was characterized via spectroscopic techniques, including 1H NMR, 13C NMR, FT-IR, and HRMS. Single crystals of this compound were grown in a suitable solvent system and optimized using single - crystal X-ray diffraction and density functional theory (DFT). The theoretical and experimental values were in good agreement, as indicated by the diffraction values. DFT was used to investing ate the physicochemical properties of the compounds by analyzing their frontier molecular orbitals and molecular electrostatic potentials. [ABSTRACT FROM AUTHOR]

Three proton‐transfer salts of diphenylphosphinic acid (DPPA) with 2‐amino‐5‐(X)‐pyridine (AMPY, X = Cl, CN or CH3), namely, 2‐amino‐5‐chloropyridinium diphenylphosphinate, C5H6ClN2+·C12H10O2P− (1, X = Cl), 2‐amino‐5‐cyanopyridinium diphenylphosphinate, C6H6N3+·C12H10O2P− (2, X = CN), and 2‐amino‐5‐methylpyridinium diphenylphosphinate, C6H9N2+·C12H10O2P− (3, X = CH3), have been synthesized and characterized by FT–IR and 1H NMR spectroscopy, and X‐ray crystallography. The crystal structures of compounds 1–3 were determined in the space group P for 1 and 2, and C2/c for 3. All three compounds contain N—H...O hydrogen‐bonding interactions due to proton transfer from the O=P—OH group of DPPA as donor to the pyridine N atom of AMPY as acceptor. The proton transfer of compounds 1–3 was also verified by 1H NMR and FT–IR spectroscopy. The stoichiometry of all three proton‐transfer salts was determined to be 1:1 and the Benesi–Hildebrand equation was applied to determine the formation constant (KCT) and the molar extinction coefficient (ϵCT) in each case. Theoretical density functional theory (DFT) calculations were performed to investigate the optimized geometries, the molecular electrostatic potentials (MEP) and the highest occupied molecular orbitals (HOMO) and lowest unoccupied molecular orbitals (LUMO) of all three proton‐transfer salts. The results showed good agreement between the experimental data and the DFT computational analysis. [ABSTRACT FROM AUTHOR]

The adsorption of SO2, NO2, and NH3 toxic gases on Al24N24 and Al24N23C nanocages was investigated by using density functional theory (DFT) calculations. The adsorption energies, frontier orbitals, charge transfer using natural bonding orbital (NBO) analysis, dipole moment, the partial density of states (PDOS), thermodynamic relationships, non-covalent interaction (NCI), and quantum theory of atoms in molecules (QTAIM) were considered. The results reveal that carbon-doped Al24N24 nanocage increases the adsorption energies for SO2 and NO2 gases while decreasing the adsorption energy of NH3 gas. The ΔG for all configurations were negative except the configurations A1 and G2 confirming the weak adsorption of these two complexes. In conclusion, Al24N24 and Al24N23C nanocages are in general promising adsorbents for the removal of SO2, NO2, and NH3 toxic gases. The Al24N24 and Al24N23C nanocages are ideal electronic materials. [ABSTRACT FROM AUTHOR]

Surface enhanced Raman scattering (SERS) experiments were used to evaluate the adsorption and orientation of 5‐bromo‐N‐[4‐bromo‐3‐(trifluoromethyl)phenyl]‐2‐hydroxybenzamide (BTB) adsorbed on silver colloid and the results were compared to normal Raman spectra of BTB. Density functional theory (DFT) analysis was used to theoretically validate the observed spectra of BTB. BTB and BTB‐Ag6 molecular structures were optimized at first. The BTB molecule is adsorbed with the Ag6 with energy of −10.67 eV through atoms, O9, F22 and Br17 atoms. The charge transfer interaction between Ag6 clusters and BTB, which lead to BTB adsorption on Ag6 metal clusters, is confirmed by the Frontier Molecular Orbitals (FMOs) study. The BTB chemisorbed on silver with a tilted orientation, as confirmed by SERS spectral analysis and the accompanying results were theoretically justified. [ABSTRACT FROM AUTHOR]

This study determined the corrosion inhibition levels of benzimidazole (BIA), 1-hydroxybenzotriazole (HBT), methylbenzimidazole (MBI) and 4-phenylimidazole (PIZ). By using simulation, it was possible to have a complete relationship with the experimental work because the results were completely consistent. Density functional theory (DFT) and Monte Carlo simulations were used to calculate several quantum chemical parameters. The molecules are simulated using quantum chemical calculations with Gaussian09 software. Fundamental factors determining the corrosion order of molecules are the highest-energy occupied and lowest-energy unoccupied molecular orbitals (HOMO and LUMO), frontier molecular orbital energy, back donating energy, electrophilicity, nucleophilicity, energy gap ∆E, absolute electronegativity (χ), softness, the number of electrons (∆N) transferred from inhibitors to iron, the dipole moment (μ), the global hardness (η) and the total energy. [ABSTRACT FROM AUTHOR]

N,N'-Bis(3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-oxalamide (NNB) was synthesized via a non-solvent reaction mechanism. NNB was characterized using Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (1HNMR) spectroscopy. Inhibition of corrosion in carbon steel was studied in the presence and absence of NNB in 1 M HCl solution using standard gravimetric technique and potentiodynamic polarization at 303–323 K. This was further subjected to quantum chemical parameters using density functional theory (DFT). FTIR and 1HNMR results confirmed the synthesis of NNB. The inhibition of carbon steel corrosion by NNB obeyed Langmuir isotherm at an efficiency of 78.10%. Lowest unoccupied molecular orbital (LUMO) as well as the highest occupied molecular orbital (HOMO) revealed insight into the interaction between NNB and the corroded carbon steel. The free energy of adsorption () increased as the temperature increased while the enthalpy () revealed the inhibition process to be exothermic. [ABSTRACT FROM AUTHOR]

In this study, 1-(2-bromo-4-(dimethylamino)phenyl)-4-(2-chlorobenzyl)-[1,2,4] triazolo[4,3-a]quinazolin-5(4H)-one was synthesized via a five-step reaction and its single-crystal was obtained via solution crystallization, which was followed by crystallographic analysis. The molecular structure was calculated using density functional theory (DFT) and conformational analysis showed that the optimized molecular structure from DFT was comparable with that elucidated using X-ray diffraction. At the same time, the physicochemical properties of the compound could be understood by analyzing its frontier molecular orbitals and molecular electrostatic potentials. [ABSTRACT FROM AUTHOR]

In this research work, we study the structural, optical, electronic, and photovoltaic properties of eight thiophene-based π-conjugated organic molecules using quantum methods namely time-dependent density functional theory. In particular, we identify the relationships between the chemical structure of these π-conjugated organic molecules and their optoelectronic properties. Moreover, we calculate and compare the highest energy occupied molecular orbital and lowest energy unoccupied molecular orbital energy levels of these compounds which act as donor with the ones of the acceptorphenyl-C61-butyric acid methyl ester. As a result, the investigated molecules show a low band gap, suitable open-circuit voltage and appropriate alignment energy level between the engineered donor molecules and the acceptor phenyl-C61-butyric acid methyl ester. This theoretical study shows that these new molecules have potential properties for the development of organic heterojunction photovoltaic cells. [ABSTRACT FROM AUTHOR]

The present work focuses on the structural and antioxidant ability of the naturally occurring flavonol Hibiscetin and its glycoside Hibiscitrin investigated in gas, water, and benzene media using M06-2X functional level of density functional theory with 6–311 + G (d, p) basis set. Relaxed potential energy scans of the hydroxyl groups and the quantum theory of atoms in molecules are used to study the strength of intramolecular hydrogen bonding and non-covalent interactions, which are critical for the antioxidant action of polyphenols. Thermodynamic factors associated with polyphenols' three primary anti-radical mechanisms have been investigated. Both molecules were found to exhibit the same trend in their reaction enthalpies. The bond dissociation enthalpies of Hibiscetin are lower than Hibiscitrin. However, the difference is not well pronounced. Their comparable reactivity is confirmed by the examination of Frontier molecular orbitals (FMO) and global descriptive characteristics. According to the study, radical attacks prefer to occur at the 8-OH position. The FMO and electrostatic potential map confirm the location of the active site. [ABSTRACT FROM AUTHOR]

Gas and solvent phase stability of half sandwich complexes between cycloalkanes viz. cyclopropane, cyclobutane, cyclopentane, cyclohexane, bicyclo[2.2.2]octane and adamantane with alkali metal cations (Li+, Na+ and K+) are analysed using density functional theory (DFT). M06-2X/6-31++G(d,p) level is primarily used for the study. The studied half sandwich complexes are stable in gas phase (stabilization energy upto 26.55 kcal mol−1). Presence of solvent phase irrespective of its dielectric, imparts negative impact on the stability of the chosen complexes. The formation of the complexes is exothermic in nature. The process of complexation is both enthalpy (ΔH) and free energy (ΔG) driven. Variation in HOMO (highest occupied molecular orbital) energy also indicates towards the chemical stability of complexes. The interaction is non-covalent with primary contribution from induction component. NBO analysis indicates that C–H bond is the donor and antibonding metal orbital is the acceptor site in the process of complexation. Stability of the complexes depends on the size of the interacting monomers. [ABSTRACT FROM AUTHOR]

Context: In this study, new visible light harvesting dyes (MBR1–MBR5) have been designed as efficient materials with silyl based anchoring abilities on semiconducting units for future dye-solar cells applications. Their unique molecular structures of novel D-π-ASemiconductor type were evaluated thoroughly by density functional theory (DFT) calculations. To enhance the optical performance in visible region, a novel dye structure (MBR) was derived from the chemical structure of mordant black (MB) dye with electron acceptor semiconducting units (MBR1–MBR5). Methods: The Coulomb-attenuating Becke, 3-parameter, Lee–Yang–Parr (CAM-B3LYP) functional, which had a hybrid and long-range correlation with 6-31G + (d,p), generated a λ max (683 nm) that was very comparable to its experimental value (672 nm). The energies of highest occupied molecular orbitals (HOMO), lowest unoccupied molecular orbitals (LUMO), and their HOMO–LUMO energy gaps (HLG) were calculated. Their ionization potentials (IP) varied from 5.616 to 8.320 eV, demonstrating their good electron donating trend. The λ max values of dyes displayed a significant red shift from MBR (682 nm) value with range 565–807 nm except MBR1 which was slightly blue shifted. The dye MBR4, which had the smallest HLG (0.23 eV) had the greatest second order nonlinear optical (NLO) response of 144,234 Debye-Angstrom−1. The DFT calculated results provided insight into the creation of new silyl anchoring groups for future DSSCs material designs with increased stability and effectiveness. The goal of the current study is to forecast the development of novel NLO materials with a D-π-ASemiconductor design that use semiconductors as anchoring groups to adhere to a surface. [ABSTRACT FROM AUTHOR]