Reduced Density Gradient Research Articles

Theoretical Analysis of Coordination Geometries in Transition Metal-Histidine Complexes Using Quantum Chemical Calculations.

A theoretical investigation utilizing density functional theory (DFT) calculations was conducted to explore the coordination complexes formed between histidine (His) ligands and various divalent transition metal ions (Mn2+, Fe2+, Co2+, Ni2+, Cu2+, and Zn2+). Conformational exploration of the His ligand was initially performed to assess its stability upon coordination. Both 1:1 and 1:2 of metal-to-ligand complexes were scrutinized to elucidate their structural features and the relative stability of the complexes. This study examined the ability of His to act as a bidentate or tridentate coordinating ligand, along with the differences in coordination geometry when solvent effects were incorporated. The reduced density gradient (RDG) analysis and local electron attachment energy (LEAE) analysis were employed to elucidate the interaction planes and the nucleophilic and electrophilic properties. The electronic properties were analyzed through electrostatic potential (ESP) maps and natural population analysis (NPA) of atomic charge distributions. This computational study provides valuable insights into the diverse coordination modes of His and its interactions with divalent transition metal ions, contributing to a better understanding of the role of this amino acid ligand in the formation of transition metal complexes. The findings can aid in the design and construction of self-assembled structures involving His-metal coordination.

Single-crystal X-ray structure, theoretical (Hirshfeld, electronic properties, NBO, NLO, RDG), and molecular docking studies of three phthalimidoethanesulfonamide derivatives

The three N-substituted-2-phtalimidoethanesulfonamide derivatives, 2-(1,3-dioxoisoindolin-2- yl)-N-(2-isopropylphenyl)ethane-1-sulfonamide (I), N-(2,6-dimethylphenyl)-2-(1,3-dioxoiso indolin-2-yl)ethane-1-sulfonamide (II) and 2-(2-(morpholinosulfonyl)ethyl) isoindoline-1,3‑dione (III), were analyzed using a combined approach including single-crystal X-ray diffraction (SC-XRD), theoretical calculations with Density Functional Theory (DFT), and molecular docking studies. Phthalimide and sulfonamide compounds have recently attracted attention for their inhibitory properties against AChE and BChE enzymes. In this study, molecular and crystal structures of compounds have been confirmed by the SC-XRD technique. Optimized molecular geometries and vibrational modes have been examined and compared to experimental results. Frontier molecular orbital (HOMO-LUMO) energies, molecular electrostatic potential (MEP), natural bond orbital (NBO) analysis, and non-linear optical (NLO) properties have been investigated by DFT/B3LYP/6–311G++(d,p) method. The reduced density gradient (RDG) analysis has been performed to analyze the non-covalent interactions. The Hirshfeld surfaces and 2D fingerprint analyses have been used to determine the intermolecular interactions of compounds. Moreover, in silico docking studies are performed to investigate the interactions between N-substituted-2-phtalimidoethane sulfonamide derivatives and AChE and BChE enzymes.

Natural deep eutectic solvent-ultrasound for the extraction of flavonoids from Fructus aurantii: Theoretical screening, experimental and mechanism

To reduce the environmental pollution caused by organic solvents and improve the extraction efficiency, a green and high-effective natural deep eutectic solvent (NADES) was screened out and prepared for the extraction of flavonoids from Fructus aurantii based on the COMOS-RS and experimental verification. The results showed the results of theoretical screening and experimental verification were consistent, and Ch-Lea was the best extraction solvent, which further proved the COMOS-RS was an efficient tool for the solvent screening. Then, the extraction conditions were investigated. The optimum extraction conditions were as follows: molar ratio (1:2), water content (30%), solid–liquid ratio (1/60 g/g) and extraction time (15 min), yet the extraction temperature and power did not significantly affect the extraction yield. Under the optimal extraction condition, the extraction yield of flavonoids was 122.68 mg/g. Compared with the traditional extraction solvents (methanol and ethanol), Ch-Lea has a higher extraction yield. And the green assessment was conducted based on Eco-Scale methodology, which results indicated the Ch-Lea was more environmentally friendly than methanol and ethanol. Meanwhile, the Ch-Lea has good reusability, and the extraction yields from four reuses were 122.68 mg/g, 125.13 mg/g, 122.56 mg/g and 105.63 mg/g, respectively. Moreover, the extraction mechanism was delved into using molecular dynamics (MD) simulation and reduced density gradient (RDG) analysis. The hydrogen bond interaction, particularly the O-H bonds, between Ch-Lea and the naringin molecule emerged as the primary force driving the extraction process. In summary, Ch-Lea is a green, economical, and highly effective solvent, making it a promising candidate for flavonoid extraction from Fructus aurantii. Its potential as an alternative to traditional extraction solvents further underscores its value.

Novel series of hydrazones carrying pyrazole and triazole moiety: Synthesis, structural elucidation, quantum computational studies and antiviral activity against SARS-Cov-2

The novel series of hydrazones carrying both pyrazole and triazole moiety were synthesized and characterized using single crystal X-ray diffraction studies. It is found that the compound crystallizes in the triclinic system in the space group P1̅. Hirshfeld analysis was carried out to visualize the noncovalent intermolecular interactions which are responsible for molecular packing in the crystal. Further, density functional theory (DFT) calculations were used to calculate optimized molecular structure, stability, and a few of the quantum chemical parameters. Derived results are in good agreement with the experimentally obtained results. Analysis of frontier molecular orbitals (HOMO and LUMO) and their energy gap of the optimized structure revealed that the compound is stable in the gaseous state. Molecular electron densities, and electrostatic potential maps provide the reactive site and charge distribution of triazole group. Quantum theory of atoms in molecules (QTAIM) and reduced density gradient (RDG) analysis were carried out to explore the weak interactions present in the molecule. In addition, the synthesized compound was investigated as an inhibitor for SARS CoV-2 protease using in-silico molecular docking analysis to understand the mode of binding. The docking results showed the good binding score with Mpro protease 6LU7. Further, molecular dynamics (MD) were carried out for the best hit docked complexes.

Enhancing the Glucose Sensing Properties of Silicene Through Transition Metal Doping: a DFT Investigation

AbstractThe attractive physiochemical properties of two dimensional materials demonstrate them to be an emerging class of potential candidates for use in sensing devices. Studies have shown that silicene can act as an excellent chemical sensor; however, no work has been studied about silicene as a glucose sensor. In this paper, using density functional theory, the interaction of pristine silicene and transition metal‐doped (Ag, Au, Cu, Ni, and Pt) silicene is studied with glucose molecules. The calculated adsorption energy, energy gap, and charge transfer value confirmed that the nickel‐doped silicene sheet can be a good glucose sensor with high sensitivity, moderate recovery time, and high conductivity. Further, the electron localization function and the reduced density gradient confirm the physisorption between the glucose molecule and the metal‐doped silicene sheets.

Self-associates of 1,2,4-triazole: FTIR studies, quantum chemical calculations and topological analysis

The Fourier Transform Infrared (FTIR) spectroscopic technique has been employed to study the self-associates of 1,2,4-triazole (Htrz) in solid phase. The self-associates have been identified using density functional theory (DFT) calculations carried out on various multimers of Htrz under B3LYP/6–311++ G(d, p) level. Comparison of the experimental and theoretical frequencies of N−H andC−Hstretching absorptional bands indicate that Htrz exists as multimers upto hexamer. The Occupancy of the anti-bonding orbitals of the proton donors, Natural bond Orbital (NBO), Frontier Molecular Orbital (FMO), Electrostatic potential surface (ESP), reduced density gradient (RDG) analyses have also been executed. In addition, topological parameters have also been analysed to characterize the hydrogen bonds and proton donating covalent bonds. The analyses show that pentamer is the most stable among all the H-bonded associates and the dimer 3 in which classical and non-classical H-bond interaction coexists is the least stable. The topological parameter values suggest that the N−H bonds of dimer1/pentamer are with the highest/smallest covalent character. The criteria proposed in literature to describe the covalent nature of bonds, in particular proton donor bonds, appears to fails in the Htrz dimer in which classical and non-classical hydrogen bonds coexist.

Semilocal Kinetic Energy Density Functionals on Atoms and Diatoms.

An accurate semilocal kinetic energy density functional (KEDF) is crucial for reliable orbital-free density functional theory calculations. In our study, we assessed the performance of representative semilocal KEDFs using a more stringent indicator. Our findings highlight the superiority of the Perdew-Constantin (PC) functional in delivering energies close to the reference values. Upon analysis of the PC functional, we identified that enhancing its performance can be achieved through a more effective region selection regime. Experimenting with various region selection indicators, we discovered that the Laplacian-dependent reduced density gradient proves to be helpful. Subsequently, we empirically constructed an augmented variant of the PC functional, which not only yields energies close to the references but also, more importantly, demonstrates qualitative predictions for stable molecules and provides reasonable quantitative estimates for bond lengths in diatomic systems.

1D-Coordination Polymer of Copper(I) thiocyanate complex with metronidazole: Synthesis, crystal structure, Hirshfeld surface analysis, PXRD, Spectroscopic properties, MEP, QTAIM, π(CN)···tetrel interaction, RDG, and thermal analysis

Within 24 h of slow evaporation of the solution containing CuCl2·2H2O, metronidazole, and NH4SCN, a red-like crystalline Cu(I) complex titled [Cu(SCN)(mnz)]n (1), [where mnz = metronidazole; SCN = thiocyanate], was synthesized. The presence of SCN− during the synthesis induces reduction of the Cu(II) to Cu(I) giving rise to novel 1D coordination polymer. The compound was characterized by single crystal X-ray diffraction, powdered X-ray diffraction, spectroscopic proprieties, and Hirshfeld surface analysis. [Cu(SCN)(mnz)]n crystallizes in the monoclinic space group P21/c. The complex possesses a 1D layer structure constructed by linking the staircase-like [CuSCN]n chains. Intermolecular interactions in the crystals investigation via Hirshfeld surface analysis reveals the major contribution is from O···H/H···O interaction (22.9 %), which is due to the presence of hydrogen bonds of the O − H···O type. The thermal properties were investigated using DTA-TGA and DSC. The study comprises the interpretation of non-covalent interactions through Quantum Theory of Atoms in Molecules (QTAIM), Natural Bond Orbital (NBO) analyses, and Reduced Density Gradient (RDG). The results show the role of interactions between SCN− and mnz through multiple connections involving the oxygen, nitrogen, and sulfur lone pairs and π-bonds for constructing the unit cell. The non-covalent arrangements include very weak hydrogen bonds that cooperatively stabilize the crystal. Along with SCN− bridging copper atoms, growth in the ab plane is favored by an uncommon π···π interaction between SCN− and the imidazole ring of mnz. In this interaction, the π(SN) and π(CN) orbitals perturb the imidazole π(CN) orbital with energies of 0.36 and 0.22 kcal/mol, respectively. In the c direction, a hydrogen bond between the hydroxyl group and CH- fragment from different mnz molecules assists structure stabilization. It is accompanied by a rarely observed π(CN)···tetrel interaction, wherein SCN− donates π-electron density to the antibonding σ(CH) orbital of the methyl carbon.

Tandem Four-Component Reaction to Access Fused Polycycles Exhibiting Aggregation-Enhanced Through-Space Charge Transfer Emission.

Rapid construction of new fluorescence emitters is essential in advancing synthetic luminescent materials. This study illustrated a piperidine-promoted reaction of chiral dialdehyde with benzoylacetonitrile and malonitrile, leading to the formation of the 6/6/7 fused cyclic product in good yield. The proposed reaction mechanism involves a dual condensation/cyclization process, achieving the formation of up to six bonds for fused polycycles. The single crystal structure analysis revealed that the fused cyclic skeleton contains face-to-face naphthyl and cyanoalkenyl motifs, which act as the electronic donor and acceptor, respectively, potentially resulting in through-space charge transfer (TSCT) emission. While the TSCT emissions were weak in solution, a notable increase in luminescence intensity was observed upon aggregation, indicating bright fluorescent light. A series of theoretical analyses further supported the possibility of spatial electronic communication based on frontier molecular orbitals, the distance of charge transfer, and reduced density gradient analysis. This work not only provides guidance for the one-step synthesis of complex polycycles, but also offers valuable insights into the design of aggregation-enhanced TSCT emission materials.

Hydrogen bond thermotropic ferroelectric liquid crystal of DL-tartaric acid and 4-heptyloxybenzoic acid (1:1): Experimental and density functional theory (DFT) approach

The current research work incorporates structural, experimental and computational studies of a hydrogen bond thermotropic ferroelectric liquid crystal (HBTFLC) complex synthesised from DL-tartaric acid (DLTA) and 4-heptyloxybenzoic acid (7OBA) with 1:1 ratio. Spectroscopic studies (XRD, NMR, FTIR, UV–Vis) and Density Functional Theory (DFT) are utilized to confirm intermolecular hydrogen bonds in the synthesised complex. Polarizing Optical Microscope (POM) study confirms the phase sequence (N*, Sm C*, Sm F* and Sm G*) while Differential Scanning Calorimetry (DSC) explore the thermal properties of the mesophases. The Frontier Molecular Orbital (FMO) and Molecular Electrostatic Potential (MEP) surface analysis also explore the donor-acceptor interactions, stability and chemical reactivity of the complex. The nature of H-bond is estimated by Natural Bond Orbital (NBO) studies with the support of Atom-in-Molecules (AIM) and Reduced Density Gradient (RDG) analysis. Nonlinear Optical (NLO) properties of the complex are studied by calculating its polarizability and hyperpolarizability.

Quantum chemical computational analysis, electronic transitions, interaction mechanisms analysis by spectroscopic, molecular docking, and molecular dynamic simulation of retinol

Quantum computational simulations based on density functional theory are employed to investigate the molecular structure of Retinol. Both geometrical parameters and electronic transitions for gas and green solvents are calculated. Characteristic frequencies were identified and band assignments were achieved through normal coordinate analysis. The calculated spectra and a comparative study of the vibrational spectra, which included a variety of vibration modes, were compared with the experimental spectra. A compound’s strong reactivity may be indicated by the bandgap, which also indicates the possibility of further charge exchange through the molecule. Determination of relative electrophilicity/nucleophilicity indices of retinol was undertaken through the prediction of condensed Fukui functions, complemented by the generation of molecular electrostatic potential surface maps. This exploration was validated through meticulous correlation with reduced density gradient and isodensity surface plots. The docking analysis of retinol with different proteins was performed to confirm anti-inflammatory activity. To gain comprehensive insights into macromolecule pliability concerning protein–ligand interactions, an effective molecular dynamics simulation was conducted.

Theoretically designed M@diaza[2.2.2]cryptand complexes: the role of non-covalent interactions in promoting NLO properties of organic electrides

ABSTRACT Organic excess electron compounds with significant nonlinear optical (NLO) properties are widely employed in optoelectronic applications. Herein, single-alkali metals with diaza[2.2.2] cryptand (M@crypt,M=Li, Na, and K) are investigated for optoelectronic and NLO properties by using the density functional theory. Thermodynamic and kinetic stabilities of present complexes are computed through interaction energy (Eint) and ab-initio molecular dynamic (AIMD) simulations. M@crypt complexes carry excess electrons and mimic molecular electrides. Quantum theory of atoms in molecules (QTAIM) analysis and reduced density gradient (RDG) spectra demonstrate the roles of the weak van der Waals (vdW) interactions between metal and complexant. The remarkable hyperpolarizability (βo) value up to 1.41 × 106 au may be credited to the presence of loosely bound excess electrons. The hyper Rayleigh scattering hyperpolarizability (βHRS) is recorded up to 1.31 × 106 au for the K@crypt. Furthermore, frequency-dependent first-order and second-order hyperpolarizability is more prominent at the applied frequency of ω = 0.042823 au. The electron localizing function (ELF) and localized orbital locator (LOL) analysis further disclose the nature of interaction between alkali metal and complexant. The TD-DFT method is adopted to get excited state parameters and absorbance properties. An electron density difference map (EDDM) is exploited to evaluate the orbital contributions in excited states. Hence, the studied electride may become a promising candidate for NLO materials. We anticipate that the present work will provide insight into further development of molecular electride for optoelectronic applications.

Investigating the potential of graphene and nitrogen carbide nanosheets as efficient sensors for drug detection through theoretical analysis

Due to the advancements in nanoscience, there has been a steady rise in the utilization of low-dimensional nanomaterials as efficient sensors in clinical practice. This research undertook a theoretical investigation aimed at proposing a prospective sensor for the allopurinol (APN) drug. The study focused on examining the fundamental interactions between the drug molecule and two nanosheets, namely graphene (GNS) and nitrogen carbide (NC3NS), employing DFT B3LYP/6-31G(d,p) in both aqueous and gaseous media. A range of adsorption energy (Eads) values for APN-NC3NS conjugated structures (CSs) was observed, ranging between −31 kcal mol−1 and −20 kcal mol−1, indicating weak chemisorption. This observed interaction can be attributed to the transfer of charge from APN to NC3NS, a phenomenon verified and characterized using reduced density gradient analysis, natural bond analysis, and the quantum theory of atoms in molecules. The APN-NC3NS conjugated structure exhibited the most significant reductions in the energy gap (Eg), with a decrease of 42.37 % in the gas phase and 30.11 % in water. This observation was further supported by frontier molecular orbital (FMO) and molecular electrostatic potential (MEP) analyses. Additionally, the NC3NS nanosheet’s advantageous ability to quickly recover (within the millisecond range) positions it as a promising candidate for the efficient detection of APN molecules.

Absorption characteristics and molecular mechanism of a low viscosity iron-based ionic liquid for removing H2S

Aiming at the problem of by-product salt and volatile solvent component in industrial liquid redox process of H2S removal. A new absorbent, a 1-butyl-3-methylpyridine iron-based ionic liquid (rFeCl3/[BMP]Cl) with three iron-pyridine ratios (r=0.6, 0.8, and 1.0), was synthesized. The physicochemical properties and H2S solubility of rFeCl3/[BMP]Cl were measured and modeled. The molecular mechanism of chemical absorption of H2S by iron-based ionic liquids was explained from the interaction energy, reduced density gradient (RDG) and atoms in molecules (AIM) topology analysis, and standard reaction equilibrium constant by quantum chemical calculation. It was found that rFeCl3/[BMP]Cl have low viscosity, high solubility, and good thermal stability. Its Bronsted acidity avoids by-product salts produced in the absorption of H2S. The hydrophobicity makes the ionic liquid not diluted by the generated water during the absorption. The results of quantum chemical calculations show that rFeCl3/[BMP]Cl-H2S has moderate intermolecular interaction and large reactivity, which is consistent with the experimental results of the Henry's coefficient and reaction equilibrium constant.

Computational assessment of the use of graphene-based nanosheets as PtII chemotherapeutics delivery systems.

Graphene is the newest form of elemental carbon and it is becoming rapidly a potential candidate in the framework of nano-bio research. Many reports confirm the successful use of graphene-based materials as carriers of anticancer drugs having relatively high loading capacities compared with other nanocarriers. Here, the outcomes of a systematic study of the adsorption behavior of FDA approved PtII drugs cisplatin, oxaliplatin, and carboplatin on surface models of pristine, holey, and nitrogen-doped holey graphene are reported. DFT investigations in water solvent have been carried out considering several initial orientations of the drugs with respect to the surfaces. Adsorption free energies, calculated including basis set superposition error (BSSE) corrections, result to be significantly negative for many of the drug@carrier adducts indicating that tested layers could be used as potential carriers for the delivery of anticancer PtII drugs. The reduced density gradient (RDG) analysis allows to show that many kinds of non-covalent interactions, including canonical H-bond, are responsible for the stabilization of the formed adducts.

Efficient wastewater decontamination using magnetic bentonite-alginate beads: A comprehensive study of adsorption dynamics, regeneration, and molecular interactions

This study enhances wastewater treatment methodologies by developing magnetic bentonite-alginate beads (MBent-A beads) for adsorbing methylene blue (MB) from aqueous solutions. Experimental and computational analyses were employed to evaluate the beads' adsorption efficiency, utilizing characterization techniques including Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), point of zero charge (pHpzc), Brunauer-Emmett-Teller method (BET), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) to examine the composite’s morphology and chemistry. Findings reveal a significant adsorption capacity with the beads' specific surface area at 3.94 m2/g and a maximum adsorption capacity of 774.32 mg/g. Adsorption kinetics adhered closely to the pseudo-second-order model, indicating a rapid adsorption process, while Langmuir isotherm analysis confirmed a uniform monolayer adsorption and temperature-dependent capacities. Thermodynamic analysis showed the adsorption process to be spontaneous and exothermic, reflecting a strong affinity between MB molecules and the bead surface. The beads demonstrated durability with more than 90% removal efficiency after five regeneration cycles, highlighting a minimal decrease from 98.54% to 90.60%. In-depth theoretical investigations using density functional theory (DFT), frontier molecular orbital (FMO), reduced density gradient (RDG), and quantum theory of atoms in molecules (QTAIM) analyses identified van der Waals forces and hydrogen bonding as primary interactions driving the adsorption. The synthesis of MBent-A beads and their confirmed efficacy in dye adsorption integrates experimental research with theoretical modeling, offering a robust solution for treating dye-contaminated wastewater and underlining the potential of MBent-A beads in environmental remediation.

Molecular Hydrogen Acts as a Hydrogen Bond Proton Acceptor: From Protonated Betaine Tagging to the Weakest Hydrogen Bond.

In an attempt to gain further insights into the intermolecular interactions implied by Rizzo's group's cautionary tale related to molecular tagging in infrared multiple photon dissociation (IRMPD) spectroscopy with molecular messengers [Masson, A. . J. Chem. Phys. 2015, 143, 104313], in the present study, we provide an in-depth analysis of the noncovalent interaction between the molecular hydrogen and protonated betaine molecule in the gas phase. We aim to shed some new light on the fundamental issues concerning the wide diapason of hydrogen-bonding-type intermolecular interactions, with a wide variety of proton acceptors. We demonstrate that in the course of tagging the protonated betaine with molecular hydrogen from the OH group side, it is the σ bond of molecular hydrogen that plays the role of hydrogen-bonding proton acceptor. The tagging thus induces a small yet significant red shift of the protonated betaine O-H stretching mode. We investigate the performance of a wide range of density functional theory (DFT) functionals for the calculation of anharmonic vibrational frequency shifts of the studied system, which are essential for the correct interpretation of the experimental IRMPD data. For an accurate prediction of the OH stretching frequency shifts, specifically designed functionals such as Handy's group HCTH/407 should be applied. The empirical dispersion correction enhances the systematic overestimation of the anharmonic frequency shift, characteristic of the most widely used DFT functionals. Combining the full-wave function approach with the charge field perturbation and natural bond orbital (NBO) deletion analyses, we demonstrate that the frequency shift in the OH-tagged structure is governed by the σHH → σ*OH intermolecular charge transfer. This interaction stabilizes the OH-tagged dimer as well, in contrast to the dipole-quadrupole electrostatic interaction energy term. Topological analysis of the electron density reveals the presence of an intermolecular bond critical point with a positive value of the density Laplacian very close to the lower limit for hydrogen bonds. NCI analyses demonstrate that the OH···H2 interaction is weaker than the intramolecular CH···O one within the protonated betaine molecule, with the through of reduced density gradient appearing at less negative sign(λ2)·ρ values. Analyzing the O-H stretching vibrational potential with the second-generation absolutely localized molecular orbitals energy decomposition analysis (ALMO-EDA 2) revealed that in the case of betaineH(+) tagged from the OH group side, the permanent electrostatics (ΔEelec), polarization (ΔEpol), and charge-transfer (ΔEct) contributions to the total intermolecular interaction energy contribute favorably to the weak hydrogen bond formation and to the red shift of the fundamental O-H stretching frequency, the ΔEct contribution being the most significant in the last context. The Pauli repulsion term, on the other hand, favors an O-H stretching frequency blue shift as a consequence of the vibrational confinement effects.

Multifaceted investigation of Sulfamerazine: Insights from computational methods, experimental techniques, and molecular simulations

The powerful sulfonamide antibiotic Sulfamerazine has been the subject of in-depth study to clarify its complex molecular interactions. In order to understand Sulfamerazine's pharmacological behaviour and interactions with biological components, this comprehensive study uses computational tools such as Density Functional Theory (DFT) calculations, spectroscopic analyses, and molecular docking simulations. Exploitation B3LYP/6-311++G(d,p) basis set, DFT simulations have provided important new understandings of the structure, vibrational properties, and binding mechanisms of this system. Vibrational assignments have been conducted by analyzing individual vibrational modes and comparing them to experimental data. The molecule's weak interactions have been identified grounded on electron density using Reduced Density Gradient Analysis. Fukui and MEP plot analyses have been employed to pinpoint the molecule's electrophilic and nucleophilic sites. Frontier molecular orbital analysis supported the observation of charge transfer within the molecule. Sulfamerazine is a viable option for further pharmaceutical development, as shown by drug-likeness and ADME (absorption, distribution, metabolism, and excretion) studies. In docking analysis, the inhibitor 6qzh stood out as particularly potent, capable of forming up to three hydrogen bonds, resulting in a binding energy of -8.2 kcal/mol. Molecular dynamics simulations have also shed light on the stability, solubility, and possible interactions of Sulfamerazine in diverse settings. This all-encompassing strategy promises to increase our understanding of the mechanism of action of Sulfamerazine, creating new opportunities for the logical development of more potent pharmaceuticals.

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.

Synthesis, characterization, and comprehensive computational analysis of aromatic hydrazone compounds: Unveiling quantum parameters, evaluating antioxidant activity, and investigating molecular docking interactions

This study presents a synergistic approach encompassing experimental synthesis, computational analysis, and antioxidant activity evaluation of two aromatic hydrazone compounds, namely 4-[(2E)-2-(2-nitrobenzylidene) hydrazinyl] benzoic acid (NBHZ) and 4-[(2E)-2-(2-hydroxybenzylidene) hydrazinyl] benzoic acid (HBHZ). Efficient synthesis yielded impressive quantities (70 % and 58 %, respectively), and structural characterization employed IR, UV–Vis, and NMR spectroscopy. Antioxidant potential was assessed using the DPPH free radical scavenging assay, revealing distinct capabilities of NBHZ and HBHZ, each featuring a nitro (NO2) and a hydroxy (OH) group, respectively, at the ortho position. HBHZ exhibited superior efficacy (IC50 = 1.15 μg/mL) compared to NBHZ (IC50 = 2.1 μg/mL) and the standard antioxidant BHT (IC50 = 1.83 μg/mL). Computational analyses using Gaussian 09 at the B3LYP/6–311 G(d,p) level elucidated electronic characteristics, molecular electrostatic potential (MEP), HOMO-LUMO energies, and global reactivity descriptors. VEDA 4 further investigated vibrational behavior and potential energy distribution (PED), topological analyses electron localization function (ELF), localized orbital locator (LOL), average localized ionization energy (ALIE), and reduced density gradient (RDG) were identified to evaluate their interactions. Thermochemical parameters explored antioxidant mechanisms (hydrogen atom transfer (HAT), single electron transfer–proton transfer (SET–PT), and sequential proton loss electron transfer (SPLET)). Molecular docking via iGEMDOCK revealed binding interactions with the target NADPH oxidase. These findings not only provide insights into the compounds' antioxidant potential but also underscore the impact of specific molecular features on their properties. This integrated approach contributes to advancing the understanding of hydrazone compounds, guiding the design of materials with tailored functionalities for applications in oxidative stress mitigation.