Molecular Electrostatic Potential Maps Research Articles

Quantum study of the competition and interplay between complexes resulting from the interaction of methylamine and halogen cyanides

In this study, quantum calculations were conducted to investigate the nature, formation mechanism, and properties of complexes resulting from the interaction between methylamine (MA) and halogen cyanide molecules (XCN, X = F, Cl, Br, and I). Three types of complexes were formed from the interaction of MA with XCN, characterized as Tetrel bond-hydrogen bond (TB-HB), Tetrel bond (TB), and Halogen bond (XB), denoted by symbols A, B, and C, respectively. The data obtained from the interaction energy indicated that complexes with structure C are significantly more stable compared to the other two structures. Molecular electrostatic potential map (MEP) analysis revealed that the size of the σ-hole of the halogen atom ligand plays a crucial role in the stability of structure C complexes. To further evaluate the properties of the resulting complexes, various analyses were conducted, including Molecular electrostatic potential map (MEP), Geometry optimization, Spectroscopy, Interaction energy (SE), Natural bond orbital (NBO), Atoms in molecules (AIM), Non-covalent interaction index (NCI), and Energy decomposition analysis (EDA).

Probing the Adsorption Sites of 5‐amino‐2‐mercaptobenzimidazole Conformations on Colloidal Gold Nanoparticles Investigated by SERS and DFT

AbstractGold nanoparticles (AuNP) have shown great potential in biomedical applications due to their unique and tunable properties. Understanding the ligand conformation on AuNP has profound interest in nanoparticle research leading to a precise drug delivery system. Colloidal AuNPs were synthesized using trisodium citrate as reducing agent. Normal Raman spectrum (NRS) in solid and aqueous phase identifies that 5‐amino‐2‐mercaptobenzimidazole (5A2MBI) mainly exist as thione form. Surface enhanced Raman scattering (SERS) investigation of 5A2MBI depending on pH was performed to explore the adsorption mechanism of thiolate and thione conformations on AuNPs. Density functional theory (DFT) calculations were used to find the band assignments and molecular electrostatic potential (MEP) mapping to identify the electron rich site where metal can interact preferentially. Using SERS spectral analysis and DFT results, surface adsorption scheme was proposed. At basic pH, 5A2MBI adsorbs on AuNP as thiolate form bidentately via Sulfur and nitrogen atom of imidazole ring with tilted geometry. However, in acidic condition the thione form adsorbs on nanosurface with perpendicular orientation.

Organo Mediated Sustainable Synthesis and In‐Silico Studies of Novel Benzisoxazole‐Chromene Acyl Hydrazones as AChE Inhibitors

AbstractA new class of benzisoxazole‐Chromene (BC) analogues containing acyl hydrazones BCA (5a‐5m) were obtained by the condensation of different benzo hydrazides with BCs in good yield. All the synthesized BCA analogues were evaluated for their in‐silico activity against Acetylcholine Esterase (AChE). According to docking experiments, the co‐crystallized ligand was outperformed by derivatives 5e (4‐benzisoxazole‐chromene‐3‐(4hydroxyphenyl) acrylohydrazide), 5m (7‐chloro,4‐hydroxy) and 5l (8‐methyl, m‐nitro) showed superior binding modes and binding free energies whereas compound 5j (8‐methyl, 4‐hydroxy) showed appropriate binding energy. These moieties containing acyl hydrazone has shown 4‐fold increase in the binding interactions and orientation. According to ADMET and toxicity studies, derivatives 5e, 5m, 5j, and 5l had the potential to be drugs and have proven to be safe when evaluated using seven toxicity models. Further on checking selectivity with the other cholinesterase enzyme, 5l came out to be selective towards AChE whereas 5e & 5j were acting on another target as well. Finally, DFT analysis validated the binding of the derivatives towards AChE and moreover Molecular Dynamic investigation revealed that 5l is the most capable candidate to interact with the target receptor by comparing its molecular orbital energies, molecular electrostatic potential maps, and ligand movement against the co‐crystallized Ligand.

Comprehensive investigation of 2-methylquinolinium-5-sulphosalicylate monohydrate: Synthesis, characterization, multifaceted analysis of molecular structure, optical, and nonlinear optical properties

We introduce the synthesis and characterization of a novel molecular salt crystal, 2-methylquinolinium-5-sulphosalicylate monohydrate (MQSSA), obtained through an equimolar reaction between donors (D) and acceptors (A) employing crystal engineering principles. The resulting proton transfer complex, MQSSA, crystallized into a monoclinic crystal system with space group P21/C, as revealed by SCXRD analysis. Significant peaks observed in PXRD analysis confirmed the crystallinity and purity of the material. FT-IR and FT-Raman spectroscopy were employed to analyze various functional groups present in the molecule. UV–Vis-NIR spectroscopy provided insights into absorbance transmittance, lower cutoff wavelength, and optical band gap, suggesting it's suitability for diverse optical applications, while characteristic emission was identified using PL measurements. Thermal stability was assessed via TG-DTA and TG-DSC techniques. Nonlinear absorption coefficient (β), nonlinear refractive index (n2), and third-order nonlinear susceptibility (χ3) were quantified using the Z-scan technique. Hirshfeld surface analysis and fingerprint plots were utilized to gain insight into intermolecular interactions and atomic arrangements within the MQSSA crystal, emphasizing the roles of crystal structure in H...H and O...H/H...O interactions. Additionally, quantum computational methods were employed to evaluate various molecular-level electronic characteristics, including molecular orbitals, molecular electrostatic potential maps, and first and second-order nonlinear optical (NLO) polarizability, providing insights into the molecular-level NLO response properties.

Structural characterization and biological activity evaluation of Magnoflorine alkaloid, a potential anticonvulsant agent

Magnoflorine (MGF), an isoquinoline alkaloid, emerges as a quaternary aporphine alkaloid derived from L-tyrosine amino acid, found in families Magnoliaceae plants and it presents important biological activity being noted for its effect on the nervous system. In this work, a deep study of structural, vibrational and electronic properties has been carried out for the MGF. From Potential Energy Surface (PES) scan the most stable conformer of alkaloid was identified and geometrical parameters were determined by Density Functional Theory (DFT) using B3LYP/6–311++G** method. A complete vibrational assignment of the normal modes was theoretical and experimentally achieved from FT-IR and Raman spectroscopies and scaled SQM methodology. Electronic transitions observed in UV–visible spectrum in aqueous medium were identified using TD-DFT methodology, with the π→π* transition being the most probable UV signal. The MEPs, the electric charge distribution along with the HOMO and LUMO frontier orbitals were analyzed and the GAP energy values justified the stability of the molecule in aqueous medium. The molecular electrostatic potential map reveals the most favourable region for electrophilic attack on MGF. Molecular docking was used to analyze the anxiolytic biological activity of the title molecule on the GABAA receptor. The results suggest an intermolecular binding capability of MFG toward both intracellular and extracellular domains of GABAA receptor, and the extracellular domain presents a higher affinity by alkaloid. Finally, the biological study infers that MGF could be used as a potential anxiolytic compound.

Investigation of sensing behavior of carbon nitride (C6N8) for detection of phosphine (PH3) and phosphorous trichloride (PCl3): A DFT approach

AbstractThis study shows the exploration of the gas‐sensing capabilities of C6N8 material against toxic gases like phosphine (PH3) and phosphorous trichloride (PCl3). First‐principles study based on M05‐2X/LanL2DZ (d, p) method was performed to investigate the interaction energy (Eint.), frontier molecular orbitals (FMOs), natural bonding orbital (NBO), noncovalent interactions (NCIs), partial density of states (PDOS), molecular electrostatic potential (MEP), and quantum theory of atoms in molecules (QTAIM) analyses. The interaction energy results showed that PCl3@C6N8 (−23.45 kJ/mol) is more stable than PH3@C6N8 (−14.79 kJ/mol). A considerable decrease in the HOMO‐LUMO band gap of C6N8 was observed as a result of its complexation with the analytes. QTAIM and NCI analyses indicated the presence of weak noncovalent interactions between C6N8 and gases (PH3 and PCl3). SAPT0 analysis was performed to quantify the NCIs. MEP maps of complexes revealed the localization of electronic density on C6N8. The little recovery time of complexes (determined at 300 K) showed that C6N8 can serve as a reusable sensing material against PH3 and PCl3. Our results demonstrate that the C6N8 surface is a reliable material for detecting phosphine and phosphorous trichloride gases.

Benzothiazole-derived Compound with Antitumor Activıiy: Molecular Structure Determination Using Density Functional Theory (Dft) Method

The Gaussian computational chemistry software package was employed to investigate the molecular structure and energetics of benzothiazole, a compound known for its anti-tumor properties. Density functional theory (DFT) calculations were conducted using the Becke, 3-parameter, Lee-Yang-Parr (B3LYP) method, coupled with the LanL2DZ basis set. Molecular structure optimization was carried out to determine the most stable configurations of the benzothiazole compound. Furthermore, thorough analyses of molecular orbital energies, molecular properties, and molecular electrostatic potential surface maps were performed on the optimized molecular system. Our current research suggests that the compound 2-(4-aminophenyl) benzothiazole, containing benzothiazole, maybe a potential drug candidate for free radical species on cells due to its anti-cancer properties.

Theoretical studies for the detailed electronic structure of organotin(IV) derivatives of 4-fluoroanthranilic acid, X-ray structure of n-dibutyltin bis(4-fluoroanthranilate)

The present study describes the detailed DFT-based electronic structure calculations without any symmetry constraints being performed on di- and triorganotin derivatives of 4-fluoroanthranilic acid (AFA), viz. Me2SnL2 (1), n-Bu2SnL2 (2), Me3SnL (3), and Ph3SnL (4) (where L= monoanion of AFA). The structural and atomic charge analysis have confirmed the previously reported our experimental results, i.e. bicapped tetrahedral and distorted tetrahedral geometry for di- and triorganotin derivatives, respectively, and all the complexes 1–4 contain a positively charged central tin atom surrounded by a negatively charged system. The single crystal X-ray structure of complex 2 (n-Bu2SnL2) also suggests that AFA acts as a monoanion and bidentate ligand resulting a bicapped tetrahedral environment around tin. Various population analysis such as Mulliken (MPA), Hirshfeld (HPA), and natural population analysis (NPA) have been employed to calculate the charges at all the atoms. A finite difference approximation method has been used to explain the charge distribution within the studied complexes 1–4 based on the conceptual global and local reactivity DFT-based descriptions, frontier molecular-orbital analysis (FMOA), and molecular electrostatic potential maps (MEP). Further, the conceptual DFT-based global reactivity descriptors and frontier molecular orbital analysis show that the interactions between CT-DNA and complexes 1–4 may be groove binding or electrostatic. The integral equation formalism-polarizable continuum model (IEF-PCM) has been employed to calculate the UV–visible spectra of 1–4 in the solvent field, whereas the same in the gas phase has been obtained with the help of time-dependent DFT (TD-DFT) at the same level of theory. The intramolecular charge distribution in 1–4 has been investigated with the help of natural bond orbital (NBO) analysis. The topological and energetic parameters at the selected bond critical points in the coordination sphere of complexes 1–4 have been calculated using atoms-in-molecules (AIM) theory. The analysis of different kinds of non-covalent interactions (NCI) in complexes 1–4 has also been investigated.

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.

Synthesis and characterization of novel quinaldic acid based Ni, Fe, and Cr Complexes: A computational and experimental study

Complexes ([Ni(quin-2-c)2(H2O)2]•2H2O, [Fe(quin-2-c)2(H2O)2], [Cr(quin-2-c)2(H2O)2] were synthesized from aqueous solutions of metal salts, quinaldic acid, and semicarbazide. In the crystal structure of the first complex, the nickel atom is chelated by the deprotonated quinaldic acid molecule through the oxygen atom of the carboxyl group, and the heterocyclic nitrogen atom, as well as two water molecules, are coordinated. The other two water molecules are located in the outer sphere. In the structure of the iron and chromium complexes, the metal atoms have a similar complex formation but do not have water molecules in the outer sphere. In all compounds, quinaldic acid acts as a bidentate ligand to form five-membered metallocycles. The electronic structure properties were investigated through theoretical modeling using the B3LYP method at the 6–31 + G(d,p) computational level. Density functional theory (DFT) was employed in quantum chemistry simulations to refine proposed structures and explore the characteristics of frontier orbitals via analysis of frontier molecular orbitals (FMOs). These computations facilitated the identification of specific sites on the surface of molecules by generating molecular electrostatic potential maps and provided insights into the structural and reactive properties. Hirshfeld surface analysis was conducted to examine intermolecular interactions, revealing a prevalence of H⋅⋅⋅H interactions.

Investigation of Anticancer Properties of 2-benzylidene-1-indanone and Its Derivatives by DFT and Molecular Docking

In this study, 2-benzylidene-1-indanone and its derivatives, which is a chalcone compound and contains indanone in its structure, were examined. Quantum chemical parameters for these compounds were calculated with the B3LYP method and the 6-31G(d) basis set and evaluated for their biological activity. The effect of different functional groups (F, Cl, Br, CF3, CH3 and OCH3) attached to the 2-benzylidene-1-indanone compound on biological activity was investigated. Some quantum chemical parameters such as highest energy filled molecule orbital energy (EHOMO), lowest non-bonding empty molecule orbital energy (ELUMO), energy gap (ΔE), hardness (η), softness (σ), global molecular electrophilicity (ω) index, global molecular nucleophilicity (ɛ) index, electron-accepting (ω+) and electron-donating (ω-) electrophilicity index were calculated for the biological activities of the compounds. Frontier molecular orbitals and molecular electrostatic potential (MEP) maps were interpreted. The biological activities of 2-benzylidine-1-indanone and some of its derivatives bearing the 1-indanone skeleton were evaluated by performing molecular docking studies with the target protein PDB ID = 1HJD corresponding to the melanoma cell line. The activity ranking obtained with quantum chemical parameters was found to be compatible with the binding energies obtained from docking results.

Molecular structure, optical, first-order hyper polarizability, electronic properties, reactivity (ELF and LOL) − computational analysis using DFT and Multiwfn for 2, 3-diaminopyridinium selenate

A detailed study on the first principle calculations of 2,3-diaminopyridinium selenite (2,3-DAPS) – an organometallic salt has been performed using B3LYP/6–311++G(d,p). Single crystal X-ray diffraction (XRD) analysis confirms that the crystal formed exhibits a monoclinic crystal structure, specifically belonging to the centrosymmetric space group P21/c. The obtained primitives and interfacial angles are as follows: a = 7.4978(15)Å, b = 7.6681(15) Å, c = 14.314(3) Å, α = γ = 90°, β = 93.75(3)°, and the volume of the unit cell V = 821.2(3) (Å)3. The structure was optimized with a global minimum. The natural bonding orbital charge transfer studies between the cation and anion was performed to gain insights into their electronic interactions. Energy gap and other global chemical reactivity descriptors have been computed with the aid of molecular orbital studies. The influence of solvent on the absorption spectra provided the evidence of solvent–solute interactions and their impact on the electronic transitions within the molecule. The presence of electrophilic and nucleophilic reactivity in the chemical is indicated by the molecular electrostatic potential (MEP) map. From the nonlinear optical (NLO) studies, it has been found that the first-order hyperpolarizability value is 30.771 × 10−31 esu, which is 8.252 times that of urea. This suggests that the compound may be a better non-linear optical material and suitable for laser applications. To calculate the proportion of intermolecular interactions and examine the distribution compound's electrostatic potential, a Hirshfeld surface analysis was conducted. The analysis provided insights into the spatial arrangement of molecules and their interactions. Additionally, topology path calculations elucidated the intrinsic connectivity between critical points, shedding light on the bonding characteristics within the compound. The likelihood of electron density at bonding and anti-bonding sites was also determined using the Electron Localization Function (ELF) and Localised Orbital Locator (LOL) plots. These analyses aided in understanding the electron distribution and the nature of chemical bonding within the compound, providing valuable information about its electronic structure and reactivity.

Spectroscopic characterization and quantum chemical calculations on Favipiravir-Guanine biomolecular complex

Favipiravir, a medication, has drawn a lot of interest recently as a possible therapeutic option for viral illnesses such as the COVID-19 pandemic. In the current work, Favipiravir + Guanine combination is being spectroscopically characterized using Fourier Transformed Infrared Spectroscopy, Raman, and Surface-Enhanced Raman Spectroscopy tools. Density functional theory along with the Becke 3-Parameter, Lee-Yang-Parr method and the basis set 6-311++ G(d,p) is used to explore the molecular interactions between the monomers of Guanine and Favipiravir. The stability of the complex resulting from the charge delocalization is thoroughly examined by natural bond orbital analysis that demonstrates the C=O∙∙∙H intermolecular hydrogen bond formation. The nature of the intermolecular hydrogen bond is described using atoms in molecules analysis. Molecular electrostatic potential mapping depicts various regions of electrostatic potential for the molecules, characterizing their reactive nature. The complex’s frontier molecular orbital gap of 2.39 eV indicates a higher possibility of electronic charge transfer, which in turn enhances the chemical reactivity of the complex. An analysis of the complex’s hyperpolarizability reveals a good non-linear optical response. The antiviral activity of the Favipiravir + Guanine complex is demonstrated by its molecular docking against the 6LU7 receptor (−5.61 kcal/mol).

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.

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.

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.

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.