Molecular Electrostatic Potential Maps Research Articles

Solvent Effects on the Absorption and Emission Spectra of the [5-amino-1-bromoindolizin-3-yl](4-bromophenyl)methanone Molecule.

The effects of solvent on the absorption and emission spectra and dipole moments of the 5ABBM have been extensively studied in a series of solvents. The dipole moments in the excited state are observed to be greater than those in the ground-state in all the solvents studied for the chosen molecule. The dipole moment increase in the excited singlet state ranges from 2.42 to 24.14 D. The experimentally calculated ground state and excited state dipole moments were determined using the solvatochromatic shifts in the absorption and emission spectra as a function of dielectric constant (ɛ) and refractive index (n). These data are used to estimate the excited-state dipole moment using the experimentally determined ground-state dipole moment. A series of fifteen different organic solvents (toluene, methanol, n-butyl alcohol, ethyl acetate, DMS, acetonitrile, benzene, isopropyl alcohol, water, DMF, DCM, DIO, THF, ethanol, and octanol) were investigated at constant dye concentrations. Small changes in the fluorescence spectrum were observed for the different solvents; the highest fluorescence intensity was observed for DMS, and the lowest was observed for water. The Stokes shift in different solvents was studied for the 5ABBM molecule. This results in molecule being more polar in the excited state than in the ground state for the solvents used. The ground state dipole moments, HOMO-LUMO, and molecular electrostatic potential maps were also computed via ab initio calculations and evaluated via Gaussian 09W software.

Enhanced antioxidant activity in Imidazolium-based protic organic salts: An insight into structure activity relationship via experimental and modelling approaches

Sulfonyl hydroxide functionalized imidazolium based protic ionic liquids (PILs) have been evaluated as a new form of antioxidants. The antioxidant activity was performed using free radical quenching using UV–visible spectroscopy and cyclic voltammetry. The studies confirmed that the investigated ILs with variable anions exhibited substantial radical scavenging activity. In UV–Visible study, Glutamine based-IL ([1MeimPS][Gln]) showed least IC50 value of 95 µM indicating maximum radical quenching activity as an oxidant, while proline based-IL ([1MeimPS]Pro]) exhibited highest IC50 value of 675 µM, demonstrating least anti-oxidant activity. Moreover, cyclic voltammetry results complemented well the UV–visible findings with least IC50 value of 90 µM for [1MeimPS][Gln], showing maximum antioxidant activity, and highest IC50 value of 593 µM for [1MeimPS]Pro], exhibiting the least antioxidant activity. The presence of two primary amines moieties in glutaminate anion may be responsible for enhanced antioxidant activity by providing more active sites for radical quenching. Contrarily, lack of primary amine functionality in prolinate anion may contribute to reduced antioxidant activity of respective IL. The Density Functional Theory (DFT) calculations predicted that the trend of radical scavenging potential was comparable with the experimentally obtained IC50 values. Molecular Electrostatic Potential (MESP) Maps illustrated that [1MeimPS][Pro] has the maximum red zones indicating a poor potential against electron scavenging capacity among all the studied ILs, while blue region in [1MeimPS][Gln], corresponding to low electron density, suggested strong attraction for the incoming electrons. Also, the high electronic distribution of HOMO orbital, appreciable stability, and significant chemical potential to attack on radical species provided by [1MeimPS][Gln] with the maximum radical scavenging potential. Furthermore, the associated LUMO energy for [1MeimPS][Pro] (−1.297 eV) is quite higher than that of [1MeimPS][Gln] (−1.422 eV) which reduced the ability of [1MeimPS][Pro] to attack free radicals of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and thus have higher associated IC50 values. This is also supported by the results of chemical hardness (η) and chemical potential (μ) descriptors values indicating [1MeimPS][Pro] is least stable and reactive than [1MeimPS][Gln]. These findings further explain the least IC50 values observed experimentally and consequent enhanced antioxidant potential of [1MeimPS][Gln].

Quantum Chemical-Based Investigations and Lipophilicity Evaluations on Some Structurally Related Quinazoline Derivatives

This work was chiefly conceived to explore the substituent effects on thermodynamic, electronic and lipophilic characteristics of some quinazoline derivatives (Q1-Q4) from theoretical aspects. The variations caused by methyl, ethyl, chlorine and bromine substituents on the same carbon of the aromatic ring were evaluated with a computational approach. In accordance with this purpose, simultaneously, DFT-based calculations were performed for vacuum and two different surroundings (DMSO and water) on methaqualone (Q1), etaqualone (Q2), mecloqualone (Q3), and mebroqualone (Q4) compounds by using the B3LYP functional and 6-311++G(d, p) split-valence triple zeta basis set. The computed thermodynamic quantities revealed that the halogen substitution was more preferable. The effect of substituent modification on electrostatic surface features was evaluated visually by molecular electrostatic potential (MEP) mapping technique. To shed light on the chemical reactivity behaviors of the Q1-Q4, DFT-based reactivity identifiers were computed. Also, the intramolecular interactions affected by substitution were evaluated on the basis of the Natural Bond Orbital (NBO) theory. The NBO results revealed that π-π* interactions predominate for each compound. The lipophilic character analyzes of the mentioned compounds were evaluated both numerically and visually. The data of both methods support each other.

Evaluation of the binding efficacy of flavonol derivatives on estrogen receptors (ER) with respect to ring B hydroxylation

RationaleFlavonols are a class offlavonoidsthat have a 3-hydroxyflavonebackbone with an additional ketone group. Galangin is a form of flavonols formed with additional hydroxy groups at ring A positions 5 and 7. The hydroxylation at ring B of galangin may result in resonance and delocalization of electrons and the formation of different derivatives like kaempferol, quercetin, and myricetin. Most of these flavonols have a similarity to 17β-estradiol, the steroid sex hormone which bound to estrogen receptors (ER), a class of nuclear transcription factors involved in the regulation of many complex pathophysiological processes including breast cancer genesis and progression. Various studies have reported that most of the flavonols are antiestrogenic and show anticancer potential, but the mechanisms may be varied like estrogenic, anti-estrogenic, non-estrogenic, and biphasic activities and their mechanisms of action have not been systematically evaluated. AimThe goal of this study is to ascertain the possible interactions of flavonol derivatives to ER with respect to ring B hydroxylation and the unsaturation degree of the C2′=C3′ bond. MethodsThe variations in structure, frontier molecular orbital, molecular electrostatic potential maps, Mullikan charge population of derivatives was determined by Density functional theory (DFT) calculations at B3LYP/6-311G (d,p) level on model molecular systems. A deep insight into these interactions with ER was described by molecular docking studies. Results and discussionResults shows that the flavonol was found more affinity to ERβ and the efficacy was increased with respect to the OH group on ring B. The hydroxyl group at position 3 and 5 in ring A and C are not found much relevant. The site of ERβ is more hydrophilic while binding ligand and the electropositive and electronegative area of the molecule was increased and reaches a maximum for quercitin with the 3 OH group; after that, it found to diminish. Moreover, the reduced cavity size of ERβ and the replacement of LEU 384 with polar HIE 475 and MET 336 increased the polarity and hydrophilicity of the cavity and led to more electrostatic interaction with ligands. ERα is found to be hydrophobic and the polar interaction between the ligands and ERa is less due to open confirmation of the cavity and bulk empty space. The results also emphasize that myricetin and quercetin require less energy to activate while accounting for the values of Gibbs free energy, the electronic configuration of frontier molecular orbitals, and entropy. ConclusionThe hydroxylation on ring B has a significant importance in the chemical reactivity as well as estrogenic activity of flavonol.

Synthesis and density functional theory study of functionalized Oxazolidine-2-ones using a novel MnFe2O4@SiO2-SiO3H magnetic nanocatalyst

This study introduces MnFe2O4@SiO2-SiO3H as a novel magnetic catalyst and thoroughly investigates its structure, catalytic activity, and reusability. The synthesis of the magnetic catalyst was meticulously characterized using an array of analytical techniques. Utilizing MnFe2O4@SiO2-SiO3H, the synthesis of functionalized oxazolidine-2-ones were performed, versatile compounds widely employed in chiral auxiliaries, protecting groups, and medicinal chemistry. Remarkably, the two-step process from chalcones demonstrated one of the shortest reported pathways, highlighting the efficiency of our novel nanocatalyst. To elucidate the stability and reactivity of the synthesized products, we employed Density Functional Theory (DFT) calculations, including molecular electrostatic potential (MEP) mapping and reactivity indices such as electronegativity, electrophilic index, softness, and hardness, as well as frontier molecular orbitals (HOMO-LUMO). Furthermore, our investigations extended to the recycling capabilities of the nanocatalyst. Through a comprehensive evaluation of at least five reaction cycles, MnFe2O4@SiO2-SiO3H showcased a remarkable retention of activity (97–92 %), reaffirming its reusability and long-term potential. Our research presents MnFe2O4@SiO2-SiO3H as a highly effective and recoverable nanomagnetic catalyst for organic reactions, with demonstrated applications in synthesizing functionalized oxazolidine-2-ones. As such, our findings offer a promising alternative to traditional methods, presenting new opportunities in catalysis and materials science.

Exploring the Spectral and Nonlinear Optical Properties of Phenyl Isothiocyanate through Density Functional Theory and Molecular Docking Studies: A Comprehensive Analysis of a Potent Biologically Active Phytochemical

Quantum chemical calculations employing Density Functional Theory (DFT) with 6–31G (d,p) basis sets have yielded valuable insights into the molecular structure, Frontier Molecular Orbitals (FMOs), Mulliken Charges, and Molecular Electrostatic Potential Maps of the phenyl isothiocyanate (PITC) molecule. Spectral analysis of PITC has been conducted including Fourier transform infrared (FTIR), Fourier transform Raman (FT-RAMAN), Nuclear Magnetic Resonance (NMR), and ultraviolet-visible (UV-Vis) spectroscopy by theoretical method. Additionally, global descriptive parameters and thermal properties have also been determined. The Nonlinear Optical characteristic (NLO) has been assessed in the gas phase using the same level of theory. The investigation into toxicity revealed that the studied molecule exhibits drug-like characteristics and is non-toxic. Molecular docking studies have been employed to investigate hydrogen bond interactions, elucidating the minimal binding energy of the compound. The outcomes of the docking studies strongly suggest the significant biological activity of Phenyl Isothiocyanate, emphasizing its potential as a potent phytochemical.

Thermal, X-ray spectroscopy, morphological, density functional theory and molecular modeling studies on yttrium(III), germanium(IV), tungsten(VI), and silicon penicillinate antibiotic complexes

This manuscript elucidates the thermal stability analysis of four distinct penicillinate complexes, comprising yttrium(III), germanium(IV), tungsten(VI), and silicon, over a temperature ranging from 25 to 800°C. Thermal data revealed the high thermal stability nature of the decomposition steps. According to the spectroscopic measurements, the chemical formula of penicillinate complexes were [Y(Pin)2].Cl.6H2O complex (1), [Ge(Pin)2].2Cl.2H2O complex (2), [W(Pin)2].4Cl complex (3), and [Si(Pin)2].2Cl.2H2O complex (4). The powder XRD pattern revealed crystalline to polycrystalline natures. The synthesized penicillinate complexes were subjected to theoretical calculations utilizing density functional theory (DFT) calculations, employing the lanL2DZ/6-311G++ level of theory. The optimized geometry of each penicillinate complex was discerned, and a comprehensive evaluation of various properties, including the HOMO→LUMO electronic energy gap, molecular electrostatic potential map, and additional physical parameters, was conducted and validated against experimental findings. Molecular docking tool was used to explore the anticancer activity of the synthesized penicillinate complexes in comparison with penicillin potassium drug (Pin). For the computational investigation, two kinases — CSF1R (PDB ID: 7MFC) and MEK2 (PDB ID: 1S9I) associated with breast cancer progression and estrogen-dependent breast cancer were utilized. This comprehensive analysis provides a deeper understanding of the synthesized penicillinate complexes and their potential applications. KEY WORDS: Penicillinate complexes, TGA-DrTGA, TEM, XRD, DFT/TD-DFT, Molecular docking Bull. Chem. Soc. Ethiop. 2024, 38(4), 973-988. DOI: https://dx.doi.org/10.4314/bcse.v38i4.13

Theoretical Study of Radical Scavenging Antioxidant Activity of Coumarin Derivatives in Licorice Using DFT

Nowdays, much research is focused on exploring antioxidant activity based on natural compounds. Licorice, a traditional natural product rich in antioxidant components, has been widely used in clinical medicine. However, there is a lack of theoretical studies on the active components in licorice. In this context, the antioxidant activity of several common active components of coumarin derivatives in licorice was investigated using a density flooding theory (DFT) approach. The free radical scavenging ability of the compounds was achieved by hydrogen atom transfer (HAT), sequential electron transfer proton transfer (SET-PT) and sequential proton loss electron transfer (SPLET) mechanisms. The effect of solvent on antioxidant activity was also investigated. It was found that in the gas and benzene phases, the compounds studied preferred to undergo the HAT mechanism, while SPLET was favoured in polar solvents. In addition to the above mechanism, the HOMO and LUMO energies of the compounds as well as molecular descriptors and electrostatic potential maps were calculated and applied to predict the antioxidant activity of the compounds. The above studies allow a better understanding of the mechanism of free radical scavenging activity of coumarin derivatives from licorice.

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.

The influence of catalyst structure on acidic strength of –SO3H groups for alkyl levulinate synthesis from biomass–derived feedstocks using sulfonic acid functionalized flexible MOF catalyst

A Brönsted acidic BUT−8(Cr)–SO3H metal–organic framework was used for the synthesis of ethyl levulinate from two different biomass–derived platform chemicals viz. furfuryl alcohol and levulinic acid. The catalyst was well characterized using various methods such as PXRD, FTIR spectroscopy, acid–base titration, NH3–TPD, TGA–DTA, SEM, TEM as well as the computational density functional theory (DFT) method. The performance of BUT–8(Cr)–SO3H catalysts was found to be superior to other catalysts (HZSM–5, H–Beta, and amberlyst –15) taken in this study. The sulfonic acid moieties bound to the aromatic naphthalene structure of BUT–8(Cr)–SO3H MOF were found to have a much stronger influence on the catalytic performance than the sulfonic acid moieties bound to the styrene framework of amberlyst–15. The key discoveries regarding the Brönsted acidic characteristics were computed via DFT incorporating the hydrogen removal energy, molecular electrostatic potential maps, and stability of the conjugate base of –SO3H moieties. The trend in the DFT–derived values was in the following order: BUT–8(Cr)–SO3H > Linker–naph –SO3H > Amberlyst–15. The results also indicate the influence of Cr metal on MOF structure to increase the acidic strength of the –SO3H group. The reaction optimization using DOE, recyclability, leaching study, and substrate scope study for both pathways using BUT–8(Cr)–SO3H were obtained.

Synthesis, in vitro Anti-HIV-1RT evaluation, molecular modeling, DFT and acute oral toxicity studies of some benzotriazole derivatives

This study synthesized and evaluated a series of benzotriazole derivatives denoted 3(a-j) and 6(a-j) for their anti-HIV-1 RT activities compared to the standard drug efavirenz. Notably, compound 3 h, followed closely by 6 h, exhibited significant anti-HIV-1 RT efficacy relative to the standard drug. In vivo oral toxicity studies were conducted for the most active compound 3 h, confirming its nontoxic nature to ascertain the safety profile. By employing molecular docking techniques, we explored the potential interactions between the synthesized compounds (ligands) and a target biomolecule (protein)(PDB ID 1RT2) at the molecular level. We undertook the molecular dynamics study of 3 h, the most active compound, within the active binding pocket of the cocrystallized structure of HIV-1 RT (PDB ID 1RT2). We aimed to learn more about how biomolecular systems behave, interact, and change at the atomic or molecular level over time. Finally, the DFT-derived HOMO and LUMO orbitals, as well as analysis of the molecular electrostatic potential map, aid in discerning the reactivity characteristics of our molecule.

Evaluating the reactivity of polyvinyl alcohol/graphene nanocomposites

The synthesis and characterization of polyvinyl alcohol (PVA)/graphene nanocomposite films, through the solution casting technique, were thoroughly explored and studied. The integration of varying concentrations of graphene was systematically explored to enhance the structural and optical attributes of the PVA matrix. Comprehensive characterization employing X-ray Diffraction (XRD), Fourier-Transform Infrared (FTIR) Spectroscopy, and Ultraviolet–Visible (UV–Vis) Spectrophotometry revealed significant interactions between PVA and graphene, manifesting in a decrease in crystallinity and optical bandgap with increasing graphene content. DFT:B3LYP/6-31g(d,p) quantum mechanical level, corroborated these findings by indicating a diminished HOMO/LUMO bandgap energy. Additionally, molecular electrostatic potential mapping underscored an increase in PVA's reactivity post-graphene integration. The investigation further extends to evaluating global reactivity descriptors, providing insights through PDOS plots and QSAR analysis. The outcomes of this research underscore the potential of PVA/graphene nanocomposites for next-generation applications in flexible photovoltaic cells, transistors, and diodes.

Synthesis of bis-(benzhydryloxy) substituted axially silicon(IV) phthalocyanine: investigation of photophysical, photochemical, and computational electronic properties

Synthesis of axially disubstituted silicon(IV) phthalocyanine bearing benzhydryloxy groups obtained by reaction of SiPcCl2 with diphenylmethanol is reported. Characterization of the compound was performed by 1H and 13C NMR, UV–Vis, mass spectrometry, and FT-IR spectroscopy. Photophysical and photochemical properties were investigated. Fluorescence spectra measurements were performed in DMSO as solvent. A preferred chemical method was used to determine the amount of singlet oxygen production. Optimizations were calculated for the single-molecule Si-Pc with the 6–311 G (d, p) basis set at the B3LYP and B3PW91 levels of density functional theory (DFT). The charge transfer (or) charge delocalization between intramolecular donor–acceptor groups was determined by NBO analysis. Furthermore, molecular electrostatic potential, Fukui functions, electrophilic and nucleophilic character maps were calculated. The electronic structure and energy parameters of the investigated compound were determined to be ΔE calc = 2.19 eV by DFT calculation and ΔE opt = 1.84 by experimental UV spectrum.

Crystallographic and theoretical analysis of a spirohydantoin derivative: 3-(4‑tert-butylbenzoyl)-1,3-diazaspiro[4.5]decane-2,4‑dione

Providing structural information on drug-like compounds is a significant step in efforts to develop innovative drugs with balanced solubility, cell permeability and target binding. In this paper, a new cyclohexane-5-spirohydantoin tethered with a 4‑tert-butylbenzoyl group was synthesized and its crystal structure was determined using the single crystal X-ray diffraction. The Hirshfeld surface analysis was used to gain a preliminary insight into the proportion and nature of the intermolecular interactions in the crystal structure, while their quantitative description is further presented in terms of a systematic analysis of dimeric motifs representing different recognition modes. A combination of N–H∙∙∙O and C(sp3)–H∙∙∙O hydrogen bonds, C(sp3)–H∙∙∙π, lone-pair∙∙∙π and π∙∙∙π stacking interactions links the molecules into a bilayer having two carbonyl O atoms exposed to the exterior. Further stacking of the bilayers occurs through C(sp3)–H∙∙∙O hydrogen bonds involving these O atoms as acceptors, C(sp3)–H∙∙∙π and π∙∙∙π stacking interactions between the phenyl groups. The molecular electrostatic potential surface map reveals that the carbonyl O atoms of the hydantoin ring and the phenyl ring are electrophilic centers, while the N1–H1 group is a nucleophilic center. The calculated HOMO and LUMO energies were used to semiquantitatively estimate the global reactivity descriptors suggesting the soft nature of the molecule.

Designing the electron push-pull chromophores through the joining of triphenylamine and triphenylborane for efficient nonlinear optical and photovoltaic properties

The benzoxadiazole class of organic compounds demonstrates exceptional versatility, particularly in the realm of nonlinear optical (NLO) materials, where their unique properties find impactful applications. In the present study, we have focused on systematically designed six benzoxadiazole (BDZ) derivatives named as BDZ-1 to BDZ-6 by using 2,3,1-benzoxadiazole as a central core/π-spacer between the donor and acceptor. Triphenylamine and triphenylborane are used as donor and acceptor in all derivatives with addition of nitro and methoxy group as substitutions. B3LYP/6-311G* method of density functional theory (DFT) is employed for optimization of purposed systems while M06/6-311G* is used to check the NLO properties. The isotropic polarizability (αiso) and anisotropic polarizability (αaniso) of BDZ-6, were found to be 110.1 × 10−24 esu and 106.3 × 10−24 esu, respectively. Among our designed compounds, the BDZ-6 exhibits the highest third-order NLO polarizability, which was found to be 5954.8 × 10−36 esu corresponding to lowest transition energy of 2.00 eV. Additionally, frontier molecular orbitals (FMOs), molecular electrostatic potential maps (MEPs), electron difference density maps (EDD) and UV–Vis analysis were performed. BDZ-6 shows minimum energy gap of 2.24 eV, while it shows maximum absorption at 620 nm. The density of states (DOS) analysis reveals distinct electronic contributions of various fragments in the formation of HOMO and LUMO orbitals resulting in efficient intramolecular charge transfer (ICT). Photovoltaic findings revealed that BDZ-4 have maximum open circuit voltage of 1.70 eV with minimum dye regeneration value (0.30 eV). Our findings shed light on the design and development of novel NLO materials with BDZ derivatives.

Spectroscopic characterizations, RDG and docking study of 2-[3-(4-chlorophenyl)-5-(4-(propane-2-yl) phenyl)-4,5-dihydro-1H pyrozol-1-yl]-4-(4-fluorophenyl)-1,3-thiazole

Abstract The theoretical calculations for 2-[3-(4-chlorophenyl)-5-(4-(propane-2-yl) phenyl)-4,5-dihydro-1H-pyrazol-1-yl]-4-(4-fluorophenyl)-1,3-thiazole (CPDFT) are performed using the Density Functional Theory (DFT) technique employing the B3LYP/cc-pVDZ and LanL2MB basis sets. Theoretical infrared (IR) and Raman frequencies as well as structural investigation were performed. The molecular structure demonstrating the presence of charge transfer and determining the bond length, bond angle of the header molecule. FMO deals about the both occupied and unoccupied orbitals of the molecule are computed. A molecular electrostatic potential map was created and analysed to identify the sites of electrophilic and nucleophilic areas of CPDFT. The ligand-protein interaction of the title compound was assessed by docking studies, indicating a strong affinity between the title compound and the target macromolecules. A reduced density gradient graph, electron localization electron and Localized orbital locator was employed to discern the non-covalent interactions of CPDFT.

New Cu(II) Schiff-base complex modified on magnetic nanoparticles: Oxidation and DFT investigation

A copper magnetic nanocatalyst was facilely synthesized by surface modification of silica magnetic nanoparticles (Fe3O4@SiO2) via reaction with 3-aminopropyltrimethoxysilane (Fe3O4@SiO2@APTMS), followed by a subsequent reaction with thiophene-2-carbaldehyde to form a Schiff base (Fe3O4@SiO2@SB). Sequentially, reaction with Cu(CH3COO)2·H2O in ethanol yielded Fe3O4@SiO2@[SB@Cu] (CH3COO)2. This nanomagnetic catalyst was comprehensively characterized using Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Thermogravimetric Analysis (TGA), and Vibrating Sample Magnetometry (VSM) techniques. The catalytic proficiency of these nanoparticles was evaluated through alkene and alcohol oxidation reactions. Under optimized conditions, the nanocatalyst exhibited significant efficacy in oxidizing styrene, cyclohexene, and benzyl alcohol, with notable selectivity values of 88 %, 100 %, and 100 % for the respective formation of styrene epoxide, 2-cyclohexene-1-one, and benzoic acid. The heterogeneous copper nanocatalyst offers advantages, including high conversion rates, facile separation, and exceptional selectivity in alkene and alcohol oxidation. Additionally, this study investigated density functional theory (DFT) methods, encompassing geometric optimization, natural charge analysis, molecular electrostatic potential maps, and vibrational normal modes of the chelating ligands.

Exploring Polyaniline Nanofilaments for Enhanced Optical Recognition of Lead in Water: An Integrated Approach of Experimental and Theoretical Studies

In this study, the behavior of lead adsorbed onto polyaniline composite was examined theoretically with the DFT method and experimentally using spectrophotometry. The synthesis and characterization of polyaniline nanofilaments (PANI) were executed. Density functional theory and Becke's three‐parameter exchange functional approach were employed for quantum mechanical calculations of geometry and energy. The 6.311G** basis set and the Lee‐Yang‐Parr correlation functional method (B3LYP/DFT) were used in a water solution environment to complement the experimental data. Experimental results were visualized using 3D molecular electrostatic potential maps (MEP), which aided in the determination and explanation of various properties, including mean polarizability, total static dipole moment, anisotropy of polarizability, and mean first‐order hyperpolarizability. The findings indicate that Pb‐PANI‐EB shows promise as a potential material for non‐linear optical (NLO) applications. PANI demonstrate efficacy as a sensor capable of detecting Pb concentrations as low as 0.05 ppm. These results justify further exploration of the use of PANI in the development of a fast, economical, robust, and highly sensitive lead (Pb) sensor.

Exploring the mechanisms of diazinon adsorption onto alpha and beta cyclodextrins through molecular dynamics simulations: Insights into environmentally friendly pesticide remediation

This study investigated the adsorption of Diazinon on α and β-Cyclodextrins (CDs) through Molecular Dynamics Simulations. The entrance point variation in diazinon adsorption is analyzed, revealing distinct preferences for entry into α and β-CDs. The center of mass distance of diazinon and CDs is investigated, highlighting the dynamic behavior within β-CD. Interaction energies between diazinon, CD, and water are explored, emphasizing the significance of van der Waals interactions in diazinon adsorption. Hydrogen bonding analysis reveals preferential adsorption of diazinon on α-CD, attributed to the number and arrangement of hydrogen bonds. Free energy calculations using the Bennett acceptance ratio method indicate a stronger affinity of diazinon for α-CD, supported by molecular electrostatic potential maps. The study also examines the hydration capacity and water molecules' distribution, indicating differences between α and β-CD. Radial distribution function analysis (RDF) illustrates the adsorption process, emphasizing water molecule expulsion upon diazinon entry. Structural stability is assessed through root mean squared deviation, indicating equilibrium attainment. Gibbs free energy calculations suggest stronger hydrophobic interactions in the α-CD cavity. This comprehensive analysis contributes valuable insights into the MD of diazinon-CDs interactions, shedding light on their adsorption mechanisms and potential applications in wastewater treatment.

Unveiling the unique properties of carbon nitride (C6N8) monolayer as a novel flexible sensor for hydrogen cyanide and hydrogen fluoride: A DFT study

Surge for the advancement of sensor that accurately and selectively detect toxic materials particularly cyanides and fluorides, is expanding every day. Herein, we analyze the sensing ability of carbon nitride (C6N8) monolayer for precise detection of hydrogen cyanide (HCN) and hydrogen fluoride (HF) using DFT approach. Interaction energy analysis reveals that HF binds strongly to C6N8 monolayer which is probably due to chemical bond formation whereas, HCN adsorbed to the surface by weak van der Waals forces. The atom in molecules (AIM), the density of states (DOS), non-covalent interaction (NCI), molecular electrostatic potential (MEP), electron localization function (ELF), frontier molecular orbitals (FMO), and QNBO were used to gain a thorough understanding of the complexation of HCN and HF with monolayer. HCN and HF analytes with C6N8 monolayer exhibit slight variations in band gap energy in FMO analysis (4.206 to 4.267 eV) indicating weak NCIs. Furthermore, MEP map demonstrate that more charge transfer is occurred from the C6N8 monolayer towards HF@C6N8 resulting in a strong ionic bonding. In addition, the existence of non-covalent interactions among complexes confirmed by NCI-RDG and QTAIM analysis. A short recovery period for HCN@C6N8 (1.677 × 10−7 s) makes desorption process simpler. Appreciable selectivity of monolayer towards analytes and prospects of all findings will provide an experimentalist with practical suggestions to build highly sensitive sensors for HCN and HF using C6N8 monolayer.