Molecular Electrostatic Potential Analysis Research Articles

Synergistic Activity of Noble Trimetallic Nanofluids: Unveiling Unprecedented Antimicrobial Potential and Computational Insights.

Nanofluids hold significant promise in diverse applications, particularly in biomedicine, where noble trimetallic nanofluids outperformed their monometallic counterparts. The composition, morphology, and size of these nanofluids play pivotal roles in their functionality. Controlled synthesis methods have garnered attention, focusing on precise morphology, content, biocompatibility, and versatile chemistry. Understanding how reaction parameters such as time, reducing agents, stabilizers, precursor concentration, temperature, and pH affect size and shape during synthesis is crucial. Trimetallic nanofluids, with their ideal composition, size, surface structure, and synergistic properties, are gaining traction in antimicrobial applications. These nanofluids were tested against seven microorganisms, demonstrating a heightened antimicrobial efficacy. Computational analyses, including molecular docking, dynamics, density functional theory (DFT), molecular electrostatic potential (MESP) analysis, and absorption, distribution, metabolism, elimination, and toxicology studies (ADMET) provided insights into binding interactions, energy, reactivity, and safety profiles, affirming the antimicrobial potential of trimetallic nanofluids. These findings emphasize the importance of controlled synthesis and computational validation in harnessing the unique properties of trimetallic nanofluids for biomedical applications.

Dissolution behavior and thermodynamic study of N-ethyl-2,2-diisopropylbutylamide in fourteen mono solvents by experiments and molecular simulation

N-ethyl-2,2-diisopropylbutylamide (WS-27) is a new cooling agent with a soothing, long-lasting cooling effect, widely used in personal care and cosmetic products. The dissolution behavior of WS-27 in fourteen mono solvents (methanol, ethanol, n-propanol, isopropanol, n-butanol, n-pentanol, methyl acetate, ethyl acetate, isopropyl acetate, propyl acetate, butyl acetate, dichloromethane, cyclohexanone, and acetone) was measured using a dynamic laser monitoring method from 263.15 K to 298.15 K under 101.6 ± 1.2 kPa. In these selected solvents, the solubility of WS-27 increased with increasing temperature. The van't Hoff equation, λh equation, modified Apelblat equation, Wilson model, and NRTL (non-random two-liquid) model were applied to correlate the experimental solubility data of WS-27, and the modified Apelblat equation showed the best-fitting results. In addition, the intermolecular interactions and solvent effect were analyzed using the Hirshfeld surface analysis, molecular electrostatic potential surface analysis, and KAT-LSER model analysis to understand the dissolution behavior of WS-27. The results indicate that the solubility of WS-27 is influenced by multiple factors, and there can be other factors as well. These fundamental data can provide essential information for the crystallization and purification process of WS-27.

Nanoscale Dodecahedral and Fullerene-Type Organoboroxine and Borazine Cages from Planar Building Units.

Boroxine- and borazine-cage analogs to C20, C60, and C70 were calculated and compared in terms of structure, strain indicators, and physical properties relevant to nanoscale applications. The results show C60 and C70 type cages are less strained than the smaller congener, primarily due to minimized bending in the B-arylene-B segments. The smallest cage calculated has a diameter of 2.4 nm, which increases up to 4.9 nm by either variation of the polyhedron (C20 < C60 < C70-type cage) or organic spacer elongation between boron centers. All calculated cages are porous (apertures ranging from 0.6 to 1.9 nm). Molecular electrostatic potential and Hirshfeld population analysis revealed both nucleophilic and electrophilic sites in the interior and exterior cage surfaces. HOMO-LUMO gaps range from 3.98 to 4.89 eV and 5.10-5.18 eV for the boroxine- and borazine-cages, respectively. Our findings provide insights into the design and properties of highly porous boroxine and borazine cages for nanoscience.

Exploring the structure and dynamics of a fluorescent schiff base (1E,1′E)-1,1′-(1,4-phenylene) bis(N-(4-chlorophenyl) methamine: Synthesis, spectroscopic analysis, thermal, electronic and crystallographic study with biological applications

Schiff bases have emerged as attractive biological agents with a wide range of uses due to the extraordinary physical, chemical, and pharmacological characteristics that they possess. This study focuses on the effective synthesis of a Schiff base that is produced from 4-chloroaniline and terephthaldehyde. The success of this synthesis is supported by a variety of spectroscopic methods and Single crystal XRD analysis. The chemical that was synthesised had significant fluorescence qualities, with measured values at 457.13, 481.49, and 524.15 nm, highlighting the fact that it has the potential to be utilised in a variety of applications within the field. Using thermogravimetric analysis, the thermal stability of the compound was studied, which revealed an excellent stability at 399 °C. Thermal stability is an essential component of compound usefulness. Molecular insights were obtained by the utilisation of Density Functional Theory, which revealed an energy gap of 1.70 electron volts (eV) and electrophilic behaviour in certain atoms. The distribution of charges was brought to light through the use of Mulliken charges and molecular electrostatic potential analysis, which brought attention to the distinctive qualities of the subject molecule. An examination of the electron localization function revealed that the electron density inside carbon, nitrogen, and chlorine atoms had been delocalized. Additionally, the localised orbital locator wave function and reduced density gradient maps offered vital insights into the non-covalent interactions that were taking place within the system under investigation. In the course of the evaluation of antimicrobial efficacy, it was discovered that the chemical exhibited more powerful antibacterial activity against gram-positive B. subtilis than the conventional antibiotic amoxicillin. The antibacterial findings were further supported by molecular docking tests, which involved using particular proteins from the target species. These investigations showed that B. subtilis had a higher affinity for binding. These findings were further validated by molecular dynamic simulations. The synthesised chemical was subjected to in silico toxicity assessment using seven models, which demonstrated its non-irritating properties on the skin and eyes. The extensive analysis that is given here lays the groundwork for more targeted research on novel antibacterial drugs, with a particular focus on the safety, molecular interactions, and effectiveness of these compounds. As a result of the compound's potential applicability in biocompatible antimicrobial formulations, it is a viable candidate for improving the development of antibacterial medicines that are both effective and safe.

A Novel Mechano-Synthesized Zeolitic Tetrazolate Framework for a High-Performance Triboelectric Nanogenerator and Self-Powered Selective Neurochemical Detection.

Designing a high-performing triboelectric novel material with eco-friendly, rapid, and cost-effective synthesis is the future of material research in triboelectric nanogenerators (TENG). We report a mechanochemical ball mill synthesis of a zeolitic tetrazolate framework (ZTF-8) that is isostructural with the well-known zeolitic imidazolate framework ZIF-8. ZTF-8 is extremely stable in water, 0.1 M aqueous acid/base solutions for 75 days at 25 °C, and boiling water (100 °C) for 7 days. Kelvin probe force microscopy and molecular electrostatic surface potential computational analysis exhibited that ZTF-8 has a very high positive surface potential. Atomic force microscopy and three-dimensional digital microscopy studies reveal the high roughness profile in the ZTF-8 film. The unique structure, exceptional acid/base stability, good dielectric property, and high roughness profile combined with the extremely electropositive nature of ZTF-8 make it a suitable candidate as a polymer-free triboelectric positive material in TENG with outstanding performance (power density of 720 mW/m2). High triboelectric output was further validated using the COMSOL Multiphysics simulation tool. Simple mechanical hand tapping of the ZTF-based TENG (ZTF-TENG) device generates high electric output, which was practically used to power numerous low-powered devices like tally counter, clinical thermometer, and digital clock and also illuminates 125 light-emitting diodes. In addition, the efficiency of ZTF-TENG was utilized as a self-powered device for a selective dopamine (DA) sensor with good sensitivity (377.76 mV/μM/cm2), wide range linearity (5-120 μM), and excellent limit of detection (0.42 μM).

Identification of New Triazolo Annulated Dipyridodiazepine Derivatives as HIV-1 Reverse Transcriptase Inhibitors: Design, Synthesis, DFT, Molecular Modelling and In silico Studies

With the tremendous increase in viral infection spread and drug resistance, it is imperative to explore new efficient antiviral agents. Two series of novel compounds, triazole-annulated dipyridodiazepines 9(a-e) and methyl-substituted triazole-annulated dipyridodiazepines 10(a-e), were successfully synthesised and characterised by IR, NMR spectroscopy and mass spectrometry. The in vitro reverse transcriptase inhibitory ability of synthesized derivatives was determined using an HIV-1 reverse transcriptase assay kit. Results revealed that 9a and 10a were most potent with an IC50 of 66 and 71 nM compared with reference drug nevirapine 88nM. A density functional theory (DFT) study of the synthesized compound showed that both triazole series possess noticeably distorted butterfly-like structures, triazole and pyridine rings tilted relative to the diazepine ring and the phenyl ring is perpendicular to the diazepine ring. Significant HOMO/LUMO gap values for both series, 3.71ࣧ4.59 eV for the compounds 9(a-e) and 3.69ࣧ4.68 eV for compounds 10(a-e), suggest their quite noticeable stability. Further, these analogues were in silico analysed for molecular docking, drug-likeness, physicochemical and ADMET studies. The good binding scores (high interaction energies) obtained in the molecular docking studies are in good agreement with the molecular electrostatic potential (MEP) analysis results showing accumulations of negative and positive electrostatic potential on different parts of the molecules of the compounds studied. In conclusion, all these results suggest that synthesized analogues could be a potential candidate to inhibit HIV-1 reverse transcriptase and may be considered as lead molecules in the development of new anti-reverse transcriptase agents.

Preparation of Fe(II) − 6-chloro-3-hydroxy-7-methyl-2-(2′-thienyl)-4-oxo-4H-1-benzopyran complex for analytical, biological & computational studies

An easy, rapid, sensitive and selective spectrophotometric method which shows maximum absorbance at 433 nm to detect micro amount of Fe(II) with 6-chloro-3-hydroxy-7-methyl-2-(2′-thienyl)-4-oxo-4H benzopyran(CHMTB) has been developed which form a stable dark brownish complex in an acidic environment which is extractable in dichloromethane (DCM). The complex showed molar absorptivity coefficient and sandell’ssensitivity 2.335 x 104 l mol-1and 0.0023 µg cm−2 respectively.The correlation value and detection limit for this method is 0.9998 and 0.0893 µg ml−1 respectively. Various cations and anions/complexing agents had no effect on the detection of divalent iron.The DFT/B3LYP/6-31G(d,p) method is a commonly used computational approach used for studying molecular properties and to calculate energy gaps for complex and ligand which are foundto be 0.0767 eV and 0.1380 eV respectively. Global reactivity descriptors provide valuable information about the reactivity and stability of molecules. Molecular Electrostatic Potential (MEP) analysis is a useful tool for identifying potential sites for nucleophilic or electrophilic attacks on chemical structures. The complex interaction with anti-cancer, antibacterial, and antifungal agents had been thoroughly studied along with the selectivity of the method by its detection in presense of other metal ions.

Molecular electrostatic potential (MEP), thermodynamic properties and spectral analysis of methyl orange doped L–lysine sulfate (MLLS) semi organic crystals

AbstractSemi organic compounds enable several structural and bonding methods for the molecular engineering of novel materials. The optical analysis, methyl orange doped L‐lysine sulfate (MLLS) is an innovative NLO material enabling the rate of frequency up change for stronger systems with lasers in the UV range with clear absorption. With this experimental studies the theoretical studies of the L‐lysine sulfate and its molecules were studied using Gaussian09w software. X‐ray analysis, UV, FTIR, NMR, Mulliken Charges, HOMO‐LUMO, MEP and some related thermodynamic properties were studied. The chosen nucleophilic site is symbolized by the color red, the more popular electrophilic site has been highlighted during MEP mapping. Spectroscopical and thermodynamical properties related to functional behavior of molecules were also discussed with obtained results.

Amplifying the nonlinear optical response of sunflower-like C16S8 through superhalogen doping

Superhalogens, known for their higher electron affinity compared to halogens, exhibit a unique ability to accept electrons from any electron donor specie. Leveraging this property, the doping of superhalogens onto electron-rich surfaces has emerged as a potent approach to augment nonlinear optical (NLO) response. Herein, we investigated the doping of beryllium trifluoride (BeF3), calcium trifluoride (CaF3) and magnesium trifluoride (MgF3) superhalogens on thia[8]circulene (C16S8) sunflower through density functional theory (DFT) calculations, to observe the improvement in the NLO response of resultant complexes. The study explores the thermal stability of complexes through interaction energy analysis, revealing robust structural properties. Conducting properties of the resultant complexes are examined via frontier molecular orbitals (FMOs) analysis, demonstrating notable changes. Molecular electrostatic potential (MEP) and Fukui function analyses gave an idea about the reactivity of the pure C16S8 and superhalogen doped C16S8 complexes. To quantify the NLO response, we assessed the first hyperpolarizability (β o) via comprehensive analysis. Remarkably, the MgF3@C16S8 complex reflects the highest hyperpolarizability value (1.85 × 104 au), signifying its exceptional NLO enhancement potential. Ultra-violet visible (UV–vis) analysis illustrated the increase in the wavelengths (red shift) of C16S8 complexes after doping of superhalogen. To elucidate the underlying factors contributing to the improved NLO response, a rationalization is provided through a two-level model.

Basic magnesium sulfate@TiO2 composite for efficient adsorption and photocatalytic degradation of 4-dodecylmorpholine in brine

More than 70% of the potash fertilizer globally is produced by the froth flotation process, in which 4-dodecylmorpholine (DMP) serves as a reverse flotation agent. As the potash fertilizer production rapidly rises, the increased DMP levels in discharged brine pose a threat to the production of high-value chemicals. In this paper, composite particles of basic magnesium sulfate@TiO2 (BMS@TiO2) were prepared using a simple and mild loading method. These particles were utilized for the adsorption and photocatalytic degradation of DMP in brine. Compared with normal powdered materials, the granular BMS@TiO2 in this study can be easily separated from liquid, and the degradation intermediates will not enter the brine without causing secondary pollution. BMS@TiO2 consists of 5·1·7 phase (5Mg(OH)2·MgSO4·7H2O) whisker clusters embedding 2.3% TiO2. The adsorption equilibrium of DMP on BMS@TiO2 particles was achieved through hydrogen bonding and pore interception with the adsorption capacity of approximately 5 mg g−1 after 6 h. The photodegradation efficiency of DMP adsorbed on BMS@TiO2 reached about 92% within 16 h, which is compared with that of pure TiO2 nanoparticles. Additionally, excellent stability and recyclability of BMS@TiO2 were also observed in five cycle tests of adsorption and photocatalytic degradation of DMP, and the possible photocatalytic degradation pathways and mechanism of DMP are proposed following molecular electrostatic potential analysis. This work provides a sustainable and environmentally friendly approach for eliminating organic micropollutants from water environments.

Substituent effect on the electronic and optical properties of newly designed pyrrole derivatives using density functional theory

Abstract This work explores six newly designed compounds obtained by several substitutions in 2,5-di(2-thienyl) pyrrole molecule. For this series of compounds, the electronic and optical properties were investigated using density functional theory and time-dependent density functional theory (TD-DFT). The new compounds were characterized by calculating the chemical parameters that correlated with their optical and electrical properties. The lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO) energies are calculated using the B3LYP functional with the 6-311G (d, p) basis set. The most low-lying energy level of the LUMO was found for Perr-NO2, indicating its effective electron injection capabilities and oxidation resistance. The HOMO and LUMO distributions of Perr-Cl and Perr-NO2 displayed a remarkable complementarity throughout each component of the two compounds, indicating an effective intermolecular charge transfer. The molecular electrostatic potential analysis demonstrated that the proposed compounds have a broad distribution of electrophilic and nucleophilic sites, which predict a high degree of chemical reactivity. The electron density analysis at the bonding and anti-bonding sites of the title compounds was performed using the electron localization function and local orbital locator techniques. Non-covalent interaction analysis using the reduced density gradient approach classified all types of interaction: repulsive, weak, and attractive interactions within compound fragments. All compounds exhibited a robust repulsive interaction, as proved by the red spikes at 0.038 a.u. The ultraviolet/visible (UV/vis) spectrum was obtained by TD-DFT using CAM-B3LYP models in conjunction with 6-311G (d, p) basis set and methanol as a solvent, the absorption bands were found within the UV range, and the maximum wavelength showed red-shifted increases. These compounds could serve as a base material for developing selective gas sensors with considerable UV/vis absorption (180–400 nm). According to the research results, the designed compounds are good candidates for use as precursors in polymer designs for optoelectronic and sensor applications due to their high electrical conductivity and photochemical properties.

Biphenyl based schiff base derivatives of 6-aminocoumarin: Design, synthesis, mesomorphic properties and DFT studies

The study focused on synthesizing two series of coumarin Schiff base liquid crystals. These series involved molecules with variations in alkoxy chains at aldehyde ends: one being the Schiff base with 4′‑hydroxy-[1,1′]-biphenyl-4-carbaldehyde (ASBP series) and the other being alkyl 4-formyl-[1,1′]-biphenyl-4-carboxylate (AEBP series). The compounds were characterized using FTIR, NMR, and Mass spectral analyses. All the compounds were studied for their mesomorphic properties, differential scanning calorimetry (DSC) and polarized optical microscopy (POM). In both the homologous series, variation of alkyl chain length showed intriguing phase transitions. In the first homologous series ASBP, compound with hexyloxy chain displayed an enantiotropic nematic (N) phase, while those with chain lengths n = 8–16 exhibited enantiotropic smectic A (SmA) mesophase. Similarly, in the AEBP series, compounds with n = 6,8 chain length showed an enantiotropic nematic (N) phase, while those with higher chain lengths n = 10–16 exhibited enantiotropic smectic A (SmA) phases. SmA mesophase was further confirmed by powdered XRD analysis. The study included DFT theoretical calculations to comprehend the compounds' mesomorphic behavior, comparing them with analogous reported compounds. Additionally, the investigation correlated experimental findings of individual compounds with calculated parameters like polarizability, dipole moment, and aspect ratio. Molecular electrostatic potential projections and analysis of frontier molecular orbitals were also employed to elucidate how polarity variations in terminal chains and mesogenic cores influenced the energy gap of FMOs and the distribution of electrostatic charges on these compounds. It has been found that the ASBP series has lower energy gap and higher dipole moment than the AEBP series.

Solid-liquid equilibrium of forchlorfenuron in four binary solvents: Experiments, hansen solubility parameter and molecular simulation

In this research, the solubility of forchlorfenuron in 4 binary solvent systems {(methanol, ethanol, n-propanol and acetone) + water} was determined at certain experimental conditions (pressure of 101.3 kPa, temperature of 278.15 K-323.15 K) using laser dynamic monitoring method. Five thermodynamic models were applied to correlate and analyze the experimentally measured data. The modified Apelblat model has the lowest value of ARD (100ARD = 2.046 %) indicates that it fits best. The apparent thermodynamic properties during the dissolution process of forchlorfenuron in the four mixed solvent systems were explored using Van't Hoff equation. The effect of solvent properties on the dissolution was explored by calculating Hansen solubility parameters. For further understanding the solubility behavior on the molecular scale, molecular electrostatic potential analysis and Hirshfeld surface analysis were conducted to visualize the molecular surface charge distribution and predict the contact behavior between forchlorfenuron and solvent. Finally, the influence of intermolecular interactions between solute and solvent on solubility behavior was explored using radial distribution function analysis based on molecular dynamics simulations. And the results show the stronger intermolecular force corresponds to the larger solubility.

Computational insight into the spectroscopic and molecular docking analysis of estrogen receptor with ligand 2,3-dimethyl-N[2-(hydroxy)benzylidene] aniline

A comprehensive approach encompassing a blend of spectral techniques and Density Functional Theory (DFT) was employed to elucidate the electronic, vibrational, structural, and nonlinear optical properties of 2,3-dimethyl-N[2-(Hydroxy)benzylidene] aniline (DNHBA). The investigation of this chemical compound involved a meticulous examination using spectroscopic techniques (FTIR, FT-Raman). The DFT calculations utilized the B3LYP method in conjunction with 6-311G (d, p) basis sets. The findings were substantiated by comparing the estimated vibrational frequencies and molecule geometry with experimental data. Using the Time Dependent −Density Functional Theory (TD-DFT) method to calculate the energy band gap of the compound at different solvents. We looked into frontier molecular orbitals (FMO) Molecular electrostatic potential (MEP) and natural bond analysis (NBO) to determine the compound’s kinetic stability and chemical reactivity. Hirshfeld surface (HS) analysis calculated the O–H..O, H-H and intermolecular interaction energy of the compound. The electron density distribution, interactions, and excitation within the title molecule are illustrated by performing topological analyses (RDG, ELF and LOL) using the Multiwfn software. In addition to these assessments, molecular dynamics provides an understanding of the system's dynamic development over a predefined duration during which atoms and molecules are permitted to interact. Utilizing the molecular docking approach allows us to energize the atomic-level interplay between small molecules and proteins within the binding sites of target proteins. This approach enhances our comprehension of vital biochemical processes associated with the behavior of small molecule. The intricacy and hazards associated with drug discovery and development processes have increased dramatically, leading to higher drug research costs.

Synthesis, solvent role, absorption and emission studies of cytosine derivative

The (E)-4-((4-hydroxy-3-methoxy-5-nitrobenzylidene) amino) pyrimidin-2(1H)-one (C5NV) was synthesized from cytosine and 5-nitrovanilline by simple straightforward condensation reaction. The structural characteristics of the compound was determined and optimized by WB97XD/cc-pVDZ basis set. The vibrational frequencies were computed and subsequently compared to the experimental frequencies. We investiated the electronic properties of the synthesized compound in gas and solvent phases using the time-dependent density functional theory (TD-DFT) approach, and compared them to experimental values. The fluorescence study showed three different wavelengths indicating the nature of the optical material properties. Frontier molecular orbital (FMO) and molecular electrostatic potential (MEP) analyses were conducted for the title compound, and electron localized functions (ELF) and localized orbital locators (LOL) were used to identify the orbital positions of localized and delocalized atoms. Non-covalent interactions (H-bond interactions) were investigated using reduced density gradients (RDGs). The objective of the study was to determine the physical, chemical, and biological properties of the C5NV. The molecular docking study was conducted between C5NV and 2XNF protein, its lowest binding energy score is −7.92 kcal/mol.

Synthesis, solvent role in TD-DFT (IEFPCM model), fluorescence and reactivity properties, topology and molecular docking studies on sulfathiazole derivative

A new class of Schiff base, 4-(butan-2-ylideneamino)-N-(thiazol-2-yl) benzenesulfonamide (EMKTH) was synthesized from sulfathiazole by simple condensation with methyl ethyl ketone. The molecular structure was characterized by infrared, 1H and 13C NMR, and UV–visible spectroscopic studies. These results were compared with theoretical values. Density functional theory (DFT) calculations were performed to determine the structure and reactivity of the molecule. Further, HOMO-LUMO, MEP, and NBO calculations were performed on this system to examine the electronic and chemical properties of this EMKTH system. The UV spectra were analyzed at ambient temperature to determine the electronic absorption maximum using TD-DFT. In the UV study, there was more solvent interaction in the solvent phase than in the gas phase, which is where the maximum wavelength was observed. Docking simulations were performed on the target protein (1W3R) in order to evaluate the binding affinity of EMKTH. It was found that the target protein had a larger energy of −3.99 kcal/mol. The findings showed that there is a significant correlation between the experimental and theoretical values. The molecule's effective charge transfer mechanism, which accounts for its high chemical reactivity, was suggested by a small orbital gap. The synthesized molecule EMKTH exhibited both intra- and intermolecular charge transfer capabilities in line with the NBO results. Analysis of the EMKTH compound's molecular electrostatic potential (MEP) revealed its reactive sites.

Quantum chemical calculation for synthesis some thiazolidin-4-one derivatives

In this study, outline the synthesis and spectroscopic characterization of novel 2-imino-thiazolidin-4-one derivatives. The synthesis process is divided into three main parts. Firstly, we prepared the starting material, 2-amino-4-(substitutedphenyl)-1,3-thiazole, by reacting thiourea with substituted acetophenone in the presence of iodine. The second part involved the synthesis of 2-chloroacetamido-4-(substitutedphenyl)-1,3-thiazole through the reaction of heterocyclic amine with chloroacetyl chloride in benzene. The third part focused on the cyclization reaction of synthesized intermediate compounds, leading to the formation of a new series of desired products, namely, 2-imino-3-[4-(substitutedphenyl)-1,3-thiazol-2-yl] thiazolidin-4-ones. The structures of the synthesized compounds were determined based on spectral data, including IR, 1HNMR, and 13CNMR. Various analytical methods were employed to explore intermolecular interactions, nonlinear optical properties, HOMO-LUMO energy gap, potential energy maps, Natural Bond Orbital (NBO) analysis, and thermodynamic parameters of diverse compounds. The assessment of weak intermolecular interactions using Noncovalent interactions (NCI) and reduced density gradient (RDG) methods revealed the presence of robust hydrogen bonds, van der Waals forces, and steric effects within the compounds. Topological parameters highlighted significant hydrogen bonding capabilities among the studied compounds. Additionally, the analysis of the HOMO-LUMO energy gap and other quantum chemical parameters unveiled the influence of protonation on polarization, chemical reactivity, and corrosion resistance. Molecular Electrostatic Potential (MEP) analysis indicated changes in electrophilicity and nucleophilicity upon the addition of protons, altering chemical reactivity. Stabilization energies of donor-acceptor interactions, assessed through Natural Bond Orbital (NBO) analysis, provided insights into charge transfer and conjugative interactions, particularly emphasizing electron delocalization within the compounds' phenyl rings.

Fe2+-NTA synergized UV254 photolytic defluorination of perfluorooctane sulfonate (PFOS): Enhancing through intramolecular electron density perturbation via electron acquisition

Perfluorooctane sulfonate (PFOS) is a persistent organic pollutant posing a risk in environmental persistence, bioaccumulation and biotoxicity. This study was to reach a comprehensive and deeper understanding of PFOS elimination in a UV254 photolytic treatment with the co-presence of Fe2+ and nitrilotriacetic acid trisodium salt (NTA). PFOS defluorination was noticeably enhanced in the UV/Fe2+-NTA treatment compared with UV/NTA, UV/Fe2+ and our previously studied UV/Fe3+ treatments. UV–vis, FTIR, and UPLC/MS-MS results indicated the formation of PFOS-Fe2+-NTA complex in PFOS, Fe2+ and NTA mixture. The transition energy gap of PFOS-Fe2+-NTA decreased below the excitation energy supplied by UV254 irradiation, corresponding with red shift appearing in UV–vis scanning spectrum. This favored intramolecular electron transfer from Fe2+-NTA to PFOS under UV254 irradiation to form electron-accepting PFOS. Molecular electrostatic potential and atom charge distribution analyses suggested electron density rearrangement and perturbation in the perfluorinated carbon chain of electron-accepting PFOS, leading to the decrease in bond dissociation energies. Intermediate products detection suggested the parallel defluorination pathways of PFOS desulfonation, middle carbon chain scission and direct C-F cleavage. NTA exhibited crucial functions in the UV/Fe2+-NTA treatment by holding Fe2+/Fe3+ in soluble form as a chelant and favoring water activation to generate hydrated electrons (eaq−) under UV irradiation as a photosensitizer. Fe2+ acting as the conduit for electron transfer and the bridge of PFOS anion and NTA was thought functioning best at 200 µM in this study. The degree of UV/Fe2+-NTA -synergized PFOS defluorination also depended on eaq− yield and UV254 photon flux. The structure dependence on the electron transfer process of PFOS and PFOA was explored incorporating molecular structure descriptors. Because of possessing greater potential to acquire electrons or less likeliness to donate its electrons than PFOA, PFOS exhibited faster defluorination kinetics in the published “reduction treatments” than “oxidation” ones. Whereas, PFOA defluorination kinetics were at similar level in both “reduction” and “oxidation” treatments.

In silico evaluation of a new compound incorporating 4(3H)-quinazolinone and sulfonamide as a potential inhibitor of a human carbonic anhydrase

The present study investigates the potential of a new compound containing sulfonamide and 4(3H)-quinazolinone to inhibit the hCA-IIX enzyme using in silico methods. Density functional theory-based calculations of electronic properties have been addressed through the analysis of frontier molecular orbitals, molecule electrostatic potential, and IR and UV–vis spectroscopy data. A molecular electrostatic potential analysis predicts that the target protein will be most inhibited by the sulfonamide groups since it has the highest potential spots for electrophile and nucleophile attack. The investigated compound exhibited good ADMET properties and satisfied the Lipinski rule of drug likeness. The hCA-IIX protein binding affinity with the proposed compound was determined by molecular docking analysis, which revealed a stable conformation with more negative binding energy (−12.19 kcal/mol) than the standard AZA drug (−7.36 kcal/mol). Moreover, a molecular dynamics study confirmed the docking results through trajectory analysis. The RMSD and RMSF both showed convergence and no significant fluctuations during the simulation time, which revealed a stable interaction within the active domain of the target protein. According to these findings, the proposed compound has a good pharmacological nature and could potentially be an efficient drug against hCAIX enzymes.

An efficient copper(II) salamo-based complex fluorescence chemosensor for detecting sulfide ions: Structure exploration and practical application

A novel salamo-based fluorescent chemical sensor l-Cu2+ was designed and prepared via the reaction of H2L and Cu(OAc)2·H2O. The whole research has found that Cu(II) atom in the complex crystal are located in the N2O2 cavity of H2L, forming a four-coordination system. Hirshfeld surface analysis confirmed the presence of hydrogen bonding and π···π stacking interactions. As a probe molecule, l-Cu2+can selectively and sensitively detect S2- without interference from other ions, and can be effectively used within the biological pH range. In addition, DFT theoretical calculations and molecular electrostatic potential analysis (ESP) were used to investigate the electron cloud density and positive and negative electrostatic potentials inside the probe, as well as the mechanism for identifying sulfur ions. Finally, the probe l-Cu2+has shown good practical application effects and can recognize S2− in three different water samples. It can also be used as a qualitative detection strip. l-Cu2+complex possesses excellent application prospect in bacteriostasis.