Electrostatic Potential Maps Research Articles

Aluminum Fluorides as Noncovalent Lewis Acids in Proteins: The Case of Phosphoryl Transfer Enzymes.

The Protein Data Bank (PDB) was scrutinized for the presence of noncovalent O ⋅ ⋅ ⋅ Al Triel Bonding (TrB) interactions, involving protein residues (e. g. GLU and GLN), adenosine/guanine diphosphate moieties (ADP and GDP), water molecules and two aluminum fluorides (AlF3 and AlF4 -). The results were statistically analyzed, revealing a vast number of O ⋅ ⋅ ⋅ Al contacts in the active sites of phosphoryl transfer enzymes, with a marked directionality towards the Al σ-/π-hole. The physical nature of the TrBs studied herein was analyzed using Molecular Electrostatic Potential (MEP) maps, the Quantum Theory of Atoms in Molecules (QTAIM), the Non Covalent Interaction plot (NCIplot) visual index and Natural Bonding Orbital (NBO) studies. As far as our knowledge extends, it is the first time that O ⋅ ⋅ ⋅ Al TrBs are analyzed within a biological context, participating in protein trapping mechanisms related to phosphoryl transfer enzymes. Moreover, since they are involved in the stabilization of aluminum fluorides inside the protein's active site, we believe the results reported herein will be valuable for those scientists working in supramolecular chemistry, catalysis and rational drug design.

DFT and Monte Carlo simulation studies of potential corrosion inhibition properties of some basic heterocyclic compounds

ABSTRACT This study utilises a combination of density functional theory (DFT) approach, 6-31G (d, p) basis set, and Monte Carlo (MC) simulations. The goal is to understand the relationship between the structure and properties of heterocyclic inhibitors and how they interact with Fe (110) surfaces. Furan, pyrrole, thiophene, pyridine, pyridazine, pyrimidine, indole, benzofuran, carbazole, quinolone, isoquinoline, and imidazole are the chemicals that were looked at in this study. The DFT calculations provide important insights into various properties of the inhibitors, such as molecular structure, dipole moments, electrostatic potential maps, Reduced Density Gradient (RDG), UV spectroscopy, and thermal characteristics. Carbazole has the smallest energy difference (4.789 eV) and the highest softness (0.209 eV−1), It also has the most chemical activity, Furthermore, the Monte Carlo models demonstrate that these derivatives have favourable adsorption energies on the Fe (110) surface. Among them, carbazole shows significant inhibitory potential. The study confirms that the carbazole compound with the biggest negative adsorption energy (−95.495) actually has the smallest energy difference and fits with the MC simulation for adsorption on Fe (110) when it is not charged. Carbazole has much stronger adsorption than oxazole, showing how the structure of a molecule affects how well an inhibitor works.

Electronic, thermodynamic, NLO, and spectroscopic properties of OAFLC compounds via DFT: A focus on 1F6B, 1F6Bi, 1F6BiN, and 1F6BN

This study presents a comprehensive quantum mechanical investigation of four novel liquid crystalline compounds: 1F6B, 1F6Bi, 1F6BiN, and 1F6BN. Using Density Functional Theory (DFT) with the B3LYP functional and 6-311G(d,p) basis set, we optimized the molecular geometries and analyzed their electronic and vibrational properties. Atomic Polar Tensor (APT) charge analysis showed significant charge distributions. Electrostatic potential (ESP) mapping identified potential reactive sites, while Electron Localization Function (ELF) and Localized Orbital Locator (LOL) analyses depicted the electron density distributions. Thermodynamic parameters indicated the compounds’ vibrational stability and responsiveness to thermal changes. Non-linear optical (NLO) properties were characterized by significant dipole moments and polarizabilities, suggesting potential in optoelectronic applications. Frontier molecular orbital analysis indicated stability with HOMO-LUMO gaps ranging from 4.15 to 4.64 eV. UV–Vis spectra revealed key electronic transitions, while Raman spectroscopy detailed various vibrational modes. The study offers valuable insights into the molecular behavior of these compounds, laying the groundwork for their future applications in material science and advanced technologies.

Charge Transfer Interaction Dynamics between 2-Methyl-8-hydroxyquinoline and 2,4-Dinitrophenol: Synthesis, Spectroscopic Characterization, DNA Binding and DFT Studies

A novel charge transfer (CT) complex was formed by combining the electron-acceptor 2,4-dinitrophenol (DNP) with the electron-donor 2-methyl-8-hydroxyquinoline (MHQ). The complex obtained was further characterized using both experimental and theoretical methods. The Benesi-Hildebrand equation can be utilized to determine various spectroscopic physical measurements such as the molar absorptivity (εCT) and formation constant (KCT). The CT complex has a stoichiometry of 1:1. Multiple spectroscopic methods were employed to investigate the resultant solid compound. The existence of charge and proton transfer in the resultant complex was confirmed by FT-IR, 1H NMR, SEM-EDX and powder-XRD studies. An electron absorption spectroscopy examination was done to analyze the complex DNA binding capability. The resulting complex was determined to have an intercalative binding mechanism, with an intrinsic binding constant (Kb) value of 4.2 × 106 M-1. The experimental results were corroborated by performing theoretical calculations using DFT using a CAM-B3LYP/6-31G(d,p) basis set. The geometrical parameters, electrostatic potential maps (MEPs) and Mullikan charges were computed and examined in agreement with the experimental observations. In addition to electron transmission, the stability of the complex is influenced by the presence of a hydrogen bond.

Synthesis, XRD structural analysis and theoretical studies of a potential inhibitor against rheumatoid arthritis (RA).

This work focused on analyzing the properties of N-(5-nitrothiazol-2-yl)furan-2-carboxamide (C8H5N3O4S, NTFC) as a possible inhibitor of the rheumatoid arthritis process. The synthesis of NTFC was carried out and good-quality crystals were obtained and studied by NMR (1H and 13C), DEPT 135, UV-Vis, IR, MS and single-crystal X-ray diffraction. The structure of NTFC consists of two rings, thiazole and furan, and a central C-N-C(=O)-C segment, which appears to be planar. This central amide segment forms angles of 2.61 (10) and 7.97 (11)° with the planes of the thiazole and furan rings, respectively. The crystal structure of NTFC exhibits N-H...N, N-H...O and C-H...O hydrogen bonds, and C-H...π and π-π interactions that facilitate self-assembly and the formation of hydrogen-bonded dimers, which implies the appearance of R22(8) graph-set motifs in this interaction. The stability of the dimeric unit is complemented by the formation of strong intramolecular C-S...O interactions of chalcogen character, with an S...O distance of 2.6040 (18) Å. Hirshfeld surface (HS) analysis revealed that O...H/H...O interactions were dominant, accounting for 36.8% of the total HS, and that N-H...N interactions were fundamental to the formation of the dimeric structure. The molecular electrostatic potential (MEP) map showed a maximum energy of 46.73 kcal mol-1 and a minimum of -36.06 kcal mol-1. The interaction energies of molecular pairs around NTFC are highest for those interactions linked by N-H hydrogen bonds. The properties of the NTFC ligand as a potential inhibitor of the DHODH (dihydroorotate dehydrogenase) enzyme were evaluated by molecular docking, showing coupling energies very close to those obtained with the control drug for rheumatoid arthritis, i.e. leflunomide.

Structural modified coumarin fused triazole analogues for Fe3+ metal ion detection: A comprehensive photophysical and fluorescent chemosensor study

This study investigates the potential of coumarin fused thiadiazole (CTR-1 and CTR-2) derivatives as chemosensors for Fe3+ ions detection. The photophysical and solvatochromic properties were examined using spectroscopic and theoretical techniques. Key parameters such as the energy bandgap, chemical hardness, softness, electronegativity, chemical potential, and electronic charge of electrophilic groups were computed using frontier molecular orbitals and compared with experimental results. Molecular electrostatic potential map studies indicated a strong electrophilic site in the molecules. Fluorescence quenching techniques demonstrated that both CTR-1 and CTR-2 exhibit strong, selective, and sensitive interactions with Fe3+ ions, with detection limits of 4.15 μM for CTR-1 and 5.02 μM for CTR-2, and rapid detection times of less than 6.5 min. Intramolecular interactions between the chemosensors and Fe3+ ions were analyzed using density functional theory and spectroscopic techniques, revealing a 1:1 binding ratio. These findings suggest that CTR-1 and CTR-2 are effective chemosensors for detecting Fe3+ions.

Synthesis and theoretical study of the stability and reactivity of some 2-[(benzimidazolyl)methylthio]-4,5-diphenylimidazole derivatives using the density functional theory (DFT) method

The stability and reactivity of the five (5) 2-[(benzimidazolyl)methylthio]-4,5-diphenylimidazole derivatives were studied using density functional theory at the B3LYP/6-31+ G (d, p) level. Analysis of the molecular electrostatic potential (MEP) map and determination of the dual descriptor showed that nitrogen N13, sulfur S5 and carbons C19 and C21 are nucleophilic. They are therefore susceptible to electrophilic attack. The nitrogens N2, N3 and N14 are shared between electrophilic and nucleophilic sites. The study of the chemical reactivity of our compounds was carried out based on the analysis of molecular frontier orbitals (HOMO and LUMO), energy gap (ΔƐ), chemical hardness (η), electrophilicity (ω) and chemical softness (S). Compound 1 was found to be the most stable, the least reactive and electron-donating. This study also opens up a new way of synthesizing biologically active molecules by modulating the C19 carbon with inductive electroattractant groups. Keywords: Benzimidazole, Imidazole, DFT, ESP, reactivity, stability.

Morphology studies, optic proprieties, hirschfeld electrostatic potential mapping, docking molecular anti-inflammatory, and dynamic molecular approaches of hybrid phosphate

The above current study intends to identify new prospects for developing viable epilepsy treatments. To attain this purpose, the created P-carboxylammonium di-hydrogen monohydrate called (I). The research reveals the existence of both intermolecular (O–H⋯O) as well as N–H⋯O intramolecular hydrogen bonding in crystal packing patterns. As the fingerprint plots illustrate the different sorts of interactions and the hybrid system's relative abundance of each, However, the molecular docking results clearly demonstrate five typical hydrogen bonds, with the best binding posture of −4.757 kcal/mol for Lys244, Val272, Arg241, and Glu273 proteins when docked with (I) ligand. As a result, we may deduce that if the (I) ligand is a pharmaceutical used to treat epilepsy, it will probably be more potent than the conventional medication. As a result, (I) was simulated using molecular dynamics (MD) and is proposed as a viable therapeutic target for antiepileptic therapy. Reduced Density Gradient (RDG) analysis, highlighted the presence of significant non-covalent interactions (NCI) that contribute to the stability and structural integrity of the compound, emphasizing the importance of these interactions in the context of its potential applications, particularly in drug design and molecular interactions. Finally, the ELF and LOL analyses collectively enhance the understanding of the electronic structure of compound I, revealing critical information about electron distribution, localization, and the nature of interactions within the molecular framework. These insights are essential for predicting the compound's reactivity and potential applications in fields such as pharmaceuticals and materials science.

Synthesis of new pyridine based ONNO type schiff bases and Cd(II) complexes, investigation of structural, electronic and anti-cancer properties as computationally and experimentally

Pyridine based Schiff bases and their Cd(II) complexes were synthesized and characterized by spectral techniques which are ATR-IR, 1H NMR, 13C NMR, LC/QTOF-MS, and Single Crystal XRD. Structural properties and geometric parameters of these compounds were investigated both experimental and computational analyses. Electronic properties of Schiff bases were investigated by Hirshfeld surface analyses and molecular electrostatic potential (MEP) map calculations. All experimentally obtained data were supported by computational chemistry methods. B3LYP/6–31G(d) level was used for synthesized Schiff bases while B3LYP/6–31G(d)(LANL2DZ) level was used for Cd(II) complexes. Cell viability assays were performed to determine anticancer properties of related compounds against breast adenocarcinoma (MCF-7), colorectal adenocarcinoma (HT-29), and gastric carcinoma (SNU-16) cell lines. It was found that anticancer activity increased with complexation. The synthesized molecules were found to be more effective against HT-29. Furthermore, molecular docking calculations for each compounds were done against histone deacetylase 1 (HDAC1) due to the fact that expression level of HDAC1 is acceptable range.

Deciphering the Nitrogen Activation Mechanisms on Group VIII Single Atoms at MoS2.

The activation of nitrogen (N2) is vital for sustainable ammonia production and nitrogen fixation technologies. This study employs density functional theory (DFT) to investigate the nitrogen activation and reduction capabilities of Group VIII single-atom catalysts anchored on MoS2. Among these, osmium anchored on MoS2 (Os@MoS2) emerged as the most promising catalyst, exhibiting the highest N2 activation and the lowest nitrogen reduction reaction (NRR) overpotential (0.624 V). A pronounced "electron drift" effect was observed for Os@MoS2, leading to significant charge redistribution that weakens the N ≡ N triple bond, facilitating its activation. The N-N dissociation energy barrier at the *N-NH2 intermediate was calculated to be only 0.82 eV, confirming Os@MoS2's superior catalytic efficiency. Detailed analyses, including electrostatic potential maps, electron localization functions, spin density, and charge transfer, revealed the pivotal role of orbital interactions in driving N2 activation. Interestingly, the trends in adsorbed N2 bond energies and NRR overpotentials showed a consistent diagonal pattern across the Group VIII catalysts, emphasizing the importance of electronic and geometric factors. This work offers valuable insights into nitrogen activation mechanisms and provides a framework for designing efficient catalysts, highlighting Os@MoS2's potential in sustainable ammonia synthesis.

Synthesis, photophysical properties, and in-silico nonlinear optics of 3-hydroxy-N-phenyl-2-naphthamide and its acetate, acrylate, and benzoate derivative

In this study, we report the successful growth of single crystals of 3-hydroxynaphthalene-2-carboxanilides (NAS) with a monoclinic structure in the P21/c space group and space group number of 14 for the first time. We have developed a yield and time-effective modified synthetic procedure using a synthetic reactor by replacing the traditional microwave method. Additionally, acylated derivatives of NAS, including novel acryloyl derivative (NAS AC), are synthesized with a modified procedure, replacing pyridine with triethylamine.We investigate the structural, photophysical, and quantum chemical properties of N-(4-acetylphenyl)-2-oxo-2H-chromene-3-carboxamide (NAS) and its acylated derivatives (NAS AC, NAS ACT, NAS BZ). Photophysical studies reveal significant Stokes shifts observed in different solvents, including time-enhanced fluorescence in DMSO, attributed to solvent relaxation processes. Natural bond orbital (NBO) analysis, molecular electrostatic potential (MEP) maps, and frontier molecular orbital (FMO) provide insights into electronic interactions and asymmetric charge distribution. Low-lying LUMO values of these compounds (-2.31 eV to -1.95 eV) support candidature for the electron acceptor applications. Nonlinear optical properties were thoroughly investigated, with NAS displaying the highest static first-order hyperpolarizability (17.89 × 10−30 esu) and NAS BZ exhibiting the highest second-order hyperpolarizability (113.09 × 10−36 esu), indicating significant nonlinear optical responses. Thermal stability (TGA and DTA) highlights the significant range of temperatures for the NLO applications.

Quantum chemical treatment, electronic energy in various solvents, spectroscopic, molecular docking and dynamic simulation studies of 2-amino-N-(2-chloro-6-methylphenyl)thiazole-5-carboxamide: A core of anticancer drug

The titled molecule 2-Amino-N-(2-chloro-6-methylphenyl)thiazole-5-carboxamide (ANMC) is a core of anticancer drug dasatinib (leukemia). Its derivatives exhibited bioactivity against breast cancer. Experimentally, the titled compound was described using NMR (1H NMR and 13C NMR), FTIR and UV–visible spectroscopy. The results were compared with the theoretical predictions, showing good agreement such as theoretical NH vibrations showed symmetric stretching and asymmetric stretching at 3429 and 3440 cm−1 respectively, λmax values appear at 305 nm for experimental and 307.75 nm for theoretical observations in acetone medium. Hirshfeld surface analysis well described the secondary internal and external interactions obtained like dnorm and di ranges −1.8551 to 1.4590 and 0.0918 to 2.6756 respectively. Comparing UV–visible spectra obtained in various solvents with the calculated TD-DFT results revealed minimal solvent effects. Molecular electrostatic potential (MEP) map and Fukui functions were employed, which indicated reactive sites of the molecule and the obtained order of nucleophilic reactivity was C16 > C2 > C8 > Cl1 > C22 > C21. The bioactivity profile probability of ANMC was theoretically explored by calculation of electrophilicity index and drug-likeness. Molecular docking of the ANMC molecule was performed with ten receptors to obtain the best ligand–protein interaction and the minimum binding energy obtained was −8.0 kcal/mol. Biomolecular stability of ANMC was investigated by Molecular Dynamic Simulation (MDS). And also the analysis of free energies showed strong interactions between the ligand and the protein.

Synthesis, vibrational, thermal, topological, electronic, electrochemical stability and DFT studies of new DABCO based ionic liquids

The design of new ILs with different anions could provide interesting physico-chemical properties and for these reasons, the knowledge about the synthesis, the thermal, vibrational, topological, electronic, electrochemical properties and interaction between the selected cation-anion in these ILs are important subjects. Therefore, the understanding about these properties of these compounds is an important subject of study. In this work, we studied three ionic liquids based on the 1-decyl-1,4-diazabicyclo[2.2.2]octane, DABCO-cation, where the corresponding anions were [Br]-, [PF6]-, and [N(SO₂CF₃)₂]-. The syntheses of these bicyclic DABCO ionic liquids are based on an alkylation reaction of 1,4-diazabicyclo[2.2.2] octane and 1-bromodecanefollowed by anion exchange. The obtained ILs are characterized by 1H, 13C, 19F and 31P-NMR spectroscopy. Vibrational spectroscopy studies are conducted by infrared (FTIR/ATR) and Raman spectroscopy in the wavenumber range 600–4000 cm-1 and 45–3500 cm-1, respectively. Furthermore, the thermal stabilities were investigated using the thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) methods. Results indicate that the thermal stability follow the order [C10DABCO][Br]<[C10DABCO][PF6]<[C10DABCO][N(SO₂CF₃)₂]. Additionally, the structural parameters, electrostatic potential (ESP) maps, interaction energies, non-covalent interaction (NCI), atoms in molecule (AIM) analysis, natural bond orbital (NBO), frontier molecular orbital (FMO) analysis and Electrochemical window (ECW) are studied and analyzed by means of DFT calculations at the M06–2X-GD3/AUG–cc–pVDZ level of theory.

Molecular insights into 5-hydroxymethylfurfural: a computational, spectroscopic, and docking investigation

The quantum chemical properties of 5-hydroxymethylfurfural were investigated using Density Functional Theory alongside vibrational spectroscopy. Key outcomes included optimizing molecular structure, vibrational frequencies, and various molecular parameters. By comparing DFT results with experimental infrared spectra, molecular motion was clarified. Reactive sites were identified through Molecular Electrostatic Potential and Fukui function analyses. Hirshfeld surface analysis revealed insights into the crystal structure’s intermolecular interactions and hydrogen bonding. Time-dependent Density Functional Theory combined with the Polarizable Continuum Model provided Ultraviolet spectra, highlighting charge transfer between the highest occupied and lowest unoccupied molecular orbitals. The compound’s electronegativity (4.7239) and electron affinity were assessed. Biological studies, including drug-likeness evaluations and molecular docking, also demonstrated potential physiological benefits, mainly through the compound’s low binding energy. A 100-nanosecond molecular dynamics simulation of the 5-HMF-4LB4 complex revealed its stability and dynamic behavior through analyses of Root Mean Square Deviation, Root Mean Square Fluctuation, hydrogen bonding, Solvent Accessible Surface Area, and radius of gyration.

In silico studies of thiazole derivative towards its potential use against SARS-CoV-2: An intuition from an experimental and computational approach

The N-(4-methoxyphenyl)-4-phenylthiazole-2-carboxamide (TT7) obtained via cyclization of methyl 2-((4-methoxyphenyl)amino)-2-oxoethanedithioate with ɑ-haloketone and then characterized by 1H-NMR and 13C-NMR spectroscopy, and single crystal X-ray diffraction method. Weak intermolecular interactions like C-H...O, C-H...π, C-O...π, and π...π interactions help to stabilize the compound TT7. The weak interactions formed in the solid structure of the compound TT7 were meticulously investigated using theoretical approach like Hirshfeld surface analysis using crystallographic information file (.cif). Further, the density functional theory calculations have been performed to obtain the optimized geometry of the structure, and to explore the electronic properties of the molecule. The charge distribution on the molecular surface is analyzed by the molecular electrostatic potential (MEP) map. QTAIM and RDG analyses were done to explore the weak interactions (intramolecular) in the compound TT7 in the gaseous phase. The compound TT7 displayed good in silico results against SARS-CoV-2 main protease. Molecular docking study on SARS-CoV-2 virus major protease (PDB IDs: 6LZE and 6LU7) shows higher docking scores. Molecular dynamics simulations confirmed the inhibitory action of the newly synthesized compound (TT7). The binding free energy and contributed energies were determined using the MM-GBSA technique. The 6LU7-ligand complex has the highest binding free energy, with considerable contributions from covalent and van der Waals interactions.

Isatin-Fluorene Schiff base as potent antidiabetic agent: Synthesis, DFT calculations, Topology, in silico ADME analysis and molecular docking studies

Diabetes mellitus is a rapidly evolving planetary challenge with substantial societal, salubrity, and financial connotations. Derivatives of isatin with hydrazides, coumarin and aldehydes have proven to possess anti-diabetic activities. Hence, as a novel perspective, isatin was merged with a polycyclic aromatic compound, 2-amino fluorene to build a Schiff base compound with anti-diabetic activity. The anti-diabetic characteristics of the designed compound were scrutinised through in silico molecular docking studies. The designed compound, (Z)-3-((9H-fluoren-2-yl)imino)indolin-2-one (FII) was synthesised in the laboratory using a simple condensation procedure. NMR, HRMS, and Infrared spectral analyses did the experimental structural characterisation of FII. The theoretical investigations of FII were evaluated via density functional theory (DFT). The DFT studies provide insight into the structure, reactivity, and electronic properties of compound FII. The most stable conformation of FII was identified and confirmed by the B3LYP method. The basis set 6-31+G(d) was used for the calculations. The DFT studies include frontier molecular orbital (FMO) analysis to define the global parameters and molecular orbital energy gap, molecular electrostatic potential (MEP) map to find out the reactive sites and natural bond orbital (NBO) analysis for understanding the electron density and charge delocalisation of the title compound, FII. Topological analyses such as ELF, LOL, RDG, and QTAIM were performed to investigate the electronic bonding parameters. Additionally, UV-visible and photoluminescence spectra were performed to investigate the optical properties of FII. The biological potential of the title compound was validated by calculating the physicochemical properties using Lipinski's rule. The molecular docking of the synthesised compound, FII, has been computed using two different proteins, exhibiting inhibitory activity against the α-Glucosidase enzyme. The binding energy and ligand efficiency of both the selected proteins with the ligand molecule were also calculated.

Synthesis, Spectral Analysis, and DFT Studies of the Novel Pyrano[3,2-c] quinoline-based 1,3,4-thiadiazole for Enhanced Solar Cell Performance

In this study, we synthesized a novel compound, 3-(5-amino-1,3,4-thiadiazol-2-yl)-6-ethyl-4-hydroxy-2H-pyrano[3,2-c]quinoline-2,5(6H)-dione (ATEHPQ), through a condensation reaction between 6-ethyl-4-hydroxy-2,5-dioxo-5,6-dihydro-2H-pyrano[3,2-c]quinoline-3-carboxaldehyde and thiosemicarbazide, followed by oxidative cyclization. We characterized ATEHPQ using elemental analysis, IR, 1H and 13C NMR spectroscopy, and mass spectrometry. Density Functional Theory (DFT) calculations with the B3LYP/6-311++G(d,p) basis set were employed to optimize the molecular geometry and analyze global reactivity descriptors, including HOMO-LUMO energies. The Molecular Electrostatic Potential (MEP) map was used to identify reactive sites, and drug-likeness studies indicated potential pharmaceutical applications. Notably, ATEHPQ showed a higher first hyperpolarizability (βtot) compared to urea, suggesting its suitability for nonlinear optical applications. We also determined the Miller indices for ATEHPQ’s preferred orientations using a specialized program. Williamson–Hall analysis revealed an average crystal size of 26.08 nm and a lattice strain of 6.3 × 10−3. The thin films exhibited three distinct absorption peaks at 2.8, 3.41, and 4.21 eV, with a direct energy gap of 2.43 eV. Dispersion parameters from the single oscillator model provided oscillator and dispersion energies of 3.12 eV and 14.21 eV, respectively, with a high-frequency dielectric constant of 4.71. The ATEHPQ thin films, when combined with n-Si, demonstrated significant improvements in photovoltaic performance: the open-circuit voltage (Voc) rose from 0.13 V to 0.521 V, the short-circuit current (Isc) increased from 0.253 mA to 2.94 mA, the fill factor (FF) improved from 0.238 to 0.33, and the efficiency (η) grew from 0.71% to 4.64% with increased illumination intensity. These results highlight the excellent photovoltaic and photodetection capabilities of ATEHPQ thin films, underscoring their potential for advanced optoelectronic and solar cell applications.

Single crystal structure features, optimization of ultrasonic conditions, density functional theory studies, and antibacterial activity of a new organic compound

The synthesis of a novel water-soluble organic compound, N’-acetyl-4-nitrobenzohydrazide, was successfully achieved using hydrothermal and sonochemical methods. The resulting products, denoted as 1 and 2, were obtained as single crystals and powder, respectively. Characterization of the crystals through single-crystal X-ray diffraction (SC-XRD) indicated a monoclinic system with space group -P 2yn. Elemental analysis (CHN), energy-dispersive X-ray spectrometer (EDS), Fourier transform infrared spectroscopy (FT-IR), thermal analysis (TGA/DTA), and powder X-ray diffraction pattern (PXRD), were utilized to analyze the molecular structure of 1 and 2, confirming their identical nature. Furthermore, scanning electron microscopy (SEM) was employed to examine the surface morphology of compounds 1 and 2, revealing distinct morphological features and varying particle dimensions. The impact of time, temperature, and ultrasonic energy was examined to optimize the morphology and particle size of compound 2. A density functional theory (DFT) study was performed to find the role of intramolecular hydrogen bond (IHB) interactions on the capability of the different tautomers of newly synthesized organic compounds. Various properties such as total energies of tautomers, energies of the most important molecular orbitals, electronegativity, thermodynamic functions, molecular electrostatic potential (MEP) maps, electron charge densities, and aromaticity were computed. The antimicrobial activity of 1, and 2 have been evaluated against one Gram-positive (Staphylococcus aureus, ATCC 25923) and one Gram-negative (Escherichia coli, ATCC 25922) using the disc diffusion method. The analysis of the inhibition zones revealed that 2 exhibit enhanced antibacterial efficacy compared to 1. This observation suggests that particle size reduction may contribute to increased antibacterial activity, potentially due to enhanced interaction with bacterial targets.

Exploring the Corrosion Potential of Three Bio-Based Furan Derivatives on Mild Steel in Aqueous HCl Solution: An Experimental Inquiry Enhanced by Theoretical Analysis.

This research deals with the corrosion inhibition of mild steel in a highly corrosive aqueous HCl medium with a concentration of 0.5 M, using three different corrosion inhibitors: furan-2-carboxylic acid (1), furan-2,5-dicarboxylic acid (2), and furan-2,5-diyldimethanol (3). Various electrochemical tests, such as potentiodynamic polarization (PP or Tafel curve) and electrochemical impedance spectroscopy, were systematically performed. The experimental results underscore the remarkable corrosion mitigating properties of inhibitors 1-3 on mild steel, showing inhibition efficiencies of 97.6, 99.5, and 95.8%, respectively, at a concentration of 5 × 10-3 M and temperature T = 298 K. Notably, the inhibition efficiency of each inhibitor 1-3 shows a positive correlation with its concentration. In addition, consistent results from all electrochemical methods confirm that 1-3 act as mixed inhibitors. These findings remain robust across different experimental techniques, ensuring the reliability and comprehensiveness of the results. Theoretically, the inhibitors were optimized using the Density Functional Theory/B3LYP/6-311++G(d,p) method in gas and aqueous phase to evaluate their reactivity and stability. Among them, compound 2 stands out for its enhanced reactivity and stability, highlighted by optimal EHOMO and ELUMO values. Negative electrostatic potential mapping suggests potential reaction centers, while Fukui functions reveal localized sites of reactivity, supported by a favorable electronic distribution and specific interactions with metal surfaces. Reduced density gradient analysis also confirms the suitability of this compound for noncovalent interactions, in agreement with experimental data.These theoretical results are in good agreement with experimental data, confirming the excellent performance of compound 2 as a corrosion inhibitor.

Influence of the Fe(II) Spin State on Iron-Ligand Bonds in Heme Model Iron-PorphyrinComplexes with 4, 5 and 6 Ligands.

In this work heme models with four [Fe(II)(P)], five [Fe(II)(P)Im], [Fe(II)(P)(Im)O2] and six ligands [Fe(II)(P)(Im)O2], where P = porphyrin, with different spin states (ms =5, 3 and 1) of the iron atom were investigated using relativistic-corrected quantum chemistry methods (PW6B95-D3-DKH/jorge-TZP-DKH). Dependence of the iron-ligand bond properties on (i) spin state and (ii) number of ligands were analyzed using natural bond orbital analysis, electron density topology, electrostatic potential and electron localization function. It is shown that reversible binding of O2 is possible in case of formation of semicoordination bond between Fe(II) and imidazole. Binding of the fifth and sixth ligand from the energetic and orbital points of view is more favorable for the triplet Fe(II) state. At the same time for the six-coordinated complex [Fe(II)(P)(Im)O2] interconversion of Fe(II) electrons of valent 3d orbital from quintet to triplet and vice versa is possible under thermal fluctuations (energy barriers less than 2 kcal/mol).