Localized Orbital Locator Research Articles

Quantum chemical investigations, Hirschfeld surface analysis, FMO, MESP, topology analyses, in-silico analysis and pharmacokinetics properties of 3-chloro-N-(4-hydroxy-3-methoxy-benzyl)-2,2-dimethyl propanamide [CHMBDP]

This article reports a comprehensive theoretical investigation of 3-chloro-n-(4-Hydroxy-3-Methoxy-Benzyl)-2,2-Dimethyl Propenamide (CHMBDP). Hirshfeld surface analysis provided a detailed visualization of intermolecular interactions within the crystal structure of CHMBDP. Analyses of Molecular Electrostatic Potential (MESP), Electron Localization Function (ELF), Localized Orbital Locator (LOL), and Reduced Density Gradient (RDG) offered insights into the compound’s reactivity and stability. The energies of the Highest Occupied Molecular Orbital (HOMO) and the Lowest Unoccupied Molecular Orbital (LUMO) indicated significant charge transfer within the molecule. In-silico analysis explored the compound’s interactions with TRPV1 (Transient Receptor Potential Vanilloid subtype 1), DNA, and BSA (Bovine Serum Albumin). The pharmacokinetic properties of CHMBDP were assessed using the Swiss ADME online tool to interpret its ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) characteristics. Overall, this study presents a thorough computational investigation of CHMBDP, characterizing its structure, properties, and potential applications.

Synthesis, experimental and theoretical spectroscopic electronic elucidation along with biological assessment and molecular docking studies on 2-(3-(1,4-diazepan-1-yl)propyl)isoindoline-1,3-dione − Antidepressant drug

The title compound, 2-[3-(1,4-diazepan-1-yl)propyl]-1H-isoindole-1,3(2H)-dione (2DPID), was synthesized from Boc-protected 2-[3-(1,4-diazepan-1-yl)propyl]-1H-isoindole-1,3(2H)-dione by treating it with trifluoroacetic acid in dichloromethane. This reaction involves the hydrolysis of the tert-butyloxycarbonyl (Boc) group under acidic conditions. The crude product was then purified by column chromatography. The purity and identity of 2DPID were confirmed through spectroscopic techniques, including 1H NMR, 13C NMR, and FT-IR. Additionally, the compound was theoretically investigated using density functional theory (DFT) to complement the experimental findings. This comprehensive approach ensured the accuracy and reliability of the synthesized compound’s characterization and confirmed its structure and purity. The research includes estimating the compound’s optimal structure and molecular geometry in both the gas and solvent phases (water, CCl4, and chloroform). Topological analysis utilizing Multiwfn 3.8 analyzer involved to elucidate the electron localization function (ELF), localized orbital locator (LOL), & Reduced density gradient (RDG) studies to locate important bonding sites and weak interactions inside the molecule. The IEFPCM framework was utilized to analyze the consequences of solvation on distinct solvents. Investigations into the effects of solvation on the electrical characteristics (Frontier molecular orbital (FMO) & UV–visible), Molecular electrostatic potential (MEP), and nonlinear optics (NLO) attributes revealed differences in the compound’s action among the gas & liquid phases. The significant presence of the solvent has a major impact on the compound’s reactivity, as the FMO’s study demonstrates by showing a higher electrophilicity index m4-descriptive value. Natural bond orbital (NBO) simulations were implemented to evaluate inter and intramolecular charge transferand stabilization. According to the MEP study, the electronegative atoms act as electrophiles, whereas the hydrogen & carbon atoms are nucleophilic. Investigations utilizing thermodynamics confirmed that significant molecular characteristics improved with temperature. Drug-likeness evaluations were used to describe the chemical’s drug attributes. Lastly, targeted protein stability was ensured by molecular docking towards antidepressant protein receptors, which was demonstrated by Ramachandran graphs. The chemical interacted with four desired protein targets (3MDM, 4HRG, 5KZN, and 7LWD) according to the molecular docking data; 4HRG had the best binding energy, at −7.63 kcal/mol.

Synthesis, quantum chemical calculations, in silico and in vitro bioactivity of a sulfonamide-Schiff base derivative

The sulfonamide Schiff base compound (E)-4-((4-(dimethylamino)benzylidene)amino)-N-(5-methylisoxazol-3-yl)benzenesulfonamide was successfully prepared and fully characterized. The foremost objective of this study was to explore the molecular geometry of the aforementioned compound and determine its drug likeness characteristics, docking ability as an insulysin inhibitor, anticancer and antioxidant activities. The molecular structure of this compound was optimized using the B3LYP/6−311G+(d,p) level of theory. The compound was completely characterized utilizing both experimental and DFT approaches. Molecular electrostatic potential, frontier molecular orbitals, Fukui function, drug likeness, and in silico molecular docking analyses of this compound were performed. Wave functional properties such as localized orbital locator, electron localization function and non-covalent interactions were also simulated. The compound was screened for anticancer and antioxidant activities using in vitro technique. The observed FT-IR, UV–Vis, and 1H NMR results compared with simulated data and both results were fairly consistent. The experimental and computational spectral findings confirm the formation of the Schiff base compound. Both π—π* and n—π* transitions were observed in both experimental and computational UV–Vis spectra. The examined compound followed to Pfizer, Golden Triangle, GSK, and Lipinski's rules. Consequently, it possesses a more favorable absorption, distribution, metabolism, excretion, and toxicity (ADMET) profile, making it a suitable candidate for non-toxic oral drug use. Moreover, the compound exhibited promising insulysin inhibition activity in an in silico molecular docking. The compound showed in vitro anticancer activity against A549 cancer cells with an IC50 value of 40.89 μg/mL and moderate antioxidant activity.

Two-Dimensional Transition Metal Phosphides As Cathode Additive in Robust Lithium-Sulfur Batteries.

The development of advanced cathode materials able to promote the sluggish redox kinetics of polysulfides is crucial to bringing lithium-sulfur batteries to the market. Herein, two electrode materials: namely, Zr2PS2 and Zr2PTe2, are identified through screening several hundred thousand compositions in the Inorganic Crystal Structure Database. First-principles calculations are performed on these two materials. These structures are similar to that of the classical MXenes. Concurrently, calculations show that Zr2PS2 and Zr2PTe2 possess high electrical conductivity, promote Li ion diffusion, and have excellent electrocatalytic activity for the Li-S reaction and particularly for the Li2S decomposition. Besides, the mechanisms behind the excellent predicted performance of Zr2PS2 and Zr2PTe2 are elucidated through electron localization function, charge density difference, and localized orbital locator. This work not only identifies two candidate sulfur cathode additives but may also serve as a reference for the identification of additional electrode materials in new generations of batteries, particularly in sulfur cathodes.

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.

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.

DFT Calculations, Molecular Docking, and Pharmacological Properties Investigation for 5-Benzoxazolecarboxylic Acid as a Target Anti-Cancer Agent

In this study, the electronic properties of the 5-Benzoxazolecarboxylic acid molecule, a benzoxazole derivative, were calculated at the DFT/B3LYP/6-311++G(d,p) level of theory. Electronic properties and chemical reactivity of the optimized structure, such as Frontier molecular orbital (FMO), global and chemical reactivity descriptors, molecular electrostatic potential (MEP), and charge analyses (APT, Hirshfeld, and NBO), were investigated. Also, electronic properties are supported by electron localization function (ELF) and localized orbital locator (LOL) analyses. Toxicity effects such as mutagenic, tumorigenic, irritant, reproductive effect, and physicochemical properties such as druglikeness and drugscore were investigated. Molecular docking studies were conducted with the vascular endothelial growth factor receptor VEGFR-2 and the PARP-2 inhibitor, which is involved in many critical cellular processes, including DNA single-stranded fracture repair and cell death control, and its effectiveness in cancer treatment was investigated.

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

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

Supramolecular clumps of μ2-1,3-acetate bridges of Cd(II)-Salen complex: Synthesis, spectroscopic characterization, crystal structure, DFT quantization's, and antifungal photodynamic therapy

The article divulges the crystal growth, synthesis, and X-ray structure characterization of one centrosymmetric cadmium complex, [Cd{CdL(μ2-1,3-acetate)}2] using Salen ligand (SL). The complex is further characterized using spectroscopic and analytical techniques, including DRS, SEM-EDX, PXRD, and ICP-MS. The crystallographic study showed that the complex has a monoclinic space P21/c. Addison parameters (Ʈ) show the hexagonal geometry of the central Cd(II) metal ion. Hirshfeld surface and 2-D fingerprint confirm supramolecular contacts despite weak C–H⋯O and C–H···π interactions. Energy frameworks, FMOs, global reactivity parameters, MEP, and energy bandgap explain the complex reactivity outlook. The complex inter- and intramolecular bonding interactions were explored through natural bond orbital (NBO), QTAIM, NCI-RDG, Electron Location Function (ELF), and Localized Orbital Locator (LOL) quantization methods. In addition, the complex and its synthetic components in vitro antibacterial efficacy were investigated using Gram-positive and Gram-negative microbial strains. SAR (structure-activity relationship) correlates with biological potency. Molecular docking assessed antimicrobial potency with proteins S. aureus (PDB ID: 1JIJ), C. albicans (PDB ID: 1M7A), E. coli (PDB ID: 1T9U), P. aeruginosa (PDB ID: 2UV0), and A. Niger (PDB ID: 3K4P). The findings are backed by the Protein-Ligand Interaction Profiler (PLIP). The antifungal potency and cell viability test of C. albicans were conducted using photodynamic therapy (APDT).

Spectroscopic characterization, DFT, antimicrobial activity and molecular docking studies on 4,5-bis[(E)-2-phenylethenyl]-1H,1′H-2,2′-biimidazole

The newly synthesized imidazole derivative namely, 4,5-bis[(E)-2-phenylethenyl]-1H,1′H-2,2′-biimidazole (KA1), was studied for its molecular geometry, docking studies, spectral analysis and density functional theory (DFT) studies. Experimental vibrational frequencies were compared with scaled ones. The reactivity sites were determined using average localized ionization analysis (ALIE), electron localized function (ELF), localized orbital locator (LOL), reduced density gradient (RDG), Fukui functions and frontier molecular orbital (FMO). Due to the solvent effect, a lower gas phase energy gap was observed. Through utilization of the noncovalent interaction (NCI) method, the hydrogen bond interaction, steric effect and Vander Walls interaction were investigated. Molecular docking simulations were employed to determine the specific atom inside the molecules that exhibits a preference for binding with protein. The parameters for the molecular electrostatic potential (MESP) and global reactivity descriptors were also determined. The thermodynamic characteristics were determined through calculations employing the B3LYP/cc-pVDZ basis set. Antimicrobial activity was carried out using the five different microorganisms like Escherichia coli, Streptococcus pneumoniae, Staphylococcus aureus, Klebsiella pneumoniae and Candida albicans.

Synthesis, spectroscopic analysis (FT-IR, FT-Raman, UV, NMR), non-covalent interactions (RDG, IGM) and dynamic simulation on Bis(8‑hydroxy quinoline) salicylate salicylic acid

Using spectrum techniques and density functional theory (DFT) reckonings, structural, vibrational and electrical characteristics of Bis(8‑hydroxy quinoline) salicylate salicylic acid (8HQSA) were determined. Characterizing the chemical under inquiry involved employing FT-IR, FT-Raman, UV–vis spectral studies and single crystal X-ray diffraction (SCXRD). For the characterization, the B3LYP approach inside the structure of DFT was employed, with a 6–311++G(d,p) basis set. The structural study shows that the stability of 8HQSA crystalline structure arising from N–H⋯O, C–O⋯H and O–H⋯O hydrogen bonding interactions. The 1H and 13C NMR chemical shifts were calculated using Gauge Independent Atomic Orbital (GIAO) technical. Vibrational frequencies and molecular geometry were computed and likened with experimental data. Here, non-covalent interactions were deeply analyzed in terms of topological parameters (AIM), electron localization function (ELF), localized orbital locator (LOL), Hirshfeld surface and reduced density gradient (RDG) method. Weak interactions such as H-bonds, van der Waals and steric effect in 8HQSA were visualized and quantified by the independent gradient density (IGM) based on the trimolecular density. The hyper-conjugative and the delocalization of charge in 8HQSA have been elucidated by natural bonding orbital (NBO) while its chemical reactivity was studied and discussed by using molecular electrostatic potential surface (MEP), frontier molecular orbital (FMOs), density of state (DOS) and partial density of state (PDOS). The positions of the molecule's nucleophilic and electrophilic groups were ascertained using Fukui analysis. To describe the size, structure, and reactive sites of the molecules, the molecular electrostatic potential and total electron density are calculated. With a band gap (2.58 eV), FMO study indicates that the material is both bioactive and stable. The ADMET factor and drug similarity are used to predict 8HQSA's pharmokinetic characteristics. Based on the findings, it can be concluded that the 8HQSA particle is optimally crystallised and recommended as a preventative measure against bacterial and fungal infections. The stability of the title compound has been investigated via molecular dynamics simulations. In-vitro antimicrobial activity results clearly reveal that in all the four strains, activity increases with increase in compound concentration and the inhibition of the strains also increases. From both molecular docking and In-vitro Antimicrobial Activity the title compound can be certified that it inhibits antimicrobial activity.

Application of density function theory (DFT) to study the microstructure property of ethyleneglycoldiacetate + 1-alcohols (C3-C8) systems from experimental point of view

For a more discussion of non-covalent interactions of binary mixtures of ethyleneglycoldiacetate (EGDA) with 1-alcohols (C3-C8), the density functional theory (DFT) calculation is applied at the ωB97XD/cc-PVDZ level of theory. The adsorption and interaction energy, thermodynamic parameters, the highest occupied molecular orbitals (HOMO) and lowest unoccupied molecular orbital (LUMO), the reduced density gradient, the localized orbital locator (LOL), and the atom in molecule (AIM) and topological parameters are also calculated for all binary mixtures at T = 298.15 K. The quantum computational reveals that the interaction of EGDA with1-alcohols is van der Walls type and all adoption process are exothermic. The computational results confirm the behavior of experimental results in the form of excess molar volumes VmEatT=298.15K and ambient pressure (81.5 kPa). The results were correlated with Redlich-Kister relation.

An efficient synthesis for Cd(II), Cu(II), and UO2(II) complexes with N-ethyl-2-(1-(naphthalen-1-yl)ethylidene)hydrazine-1-carbothioamide under solvent-free condition using ball milling as green protocol

In this study, the potent ligand of N-ethyl-2-(1-(naphthalen-1-yl)ethylidene)hydrazine-1-carbothioamide (H2AN) was synthesized by condensation reaction between 1-(naphthalen-1-yl)ethan-1-one and N-ethylhydrazinecarbothioamide. Subsequently, a series of Cd(II), Cu(II), and UO2(II) complexes were prepared via the green ball milling method and characterized using various instrumental techniques like (IR, UV-Visible,1H-NMR,13C-NMR, SEM, EDX, elemental analysis & magnetic measurements). Molecular modeling and DFT studies were carried out to confirm the proposed binding manner. Also, both electron localization function (ELF) and localized orbital locator (LOL) methods were used to approximate the concentration of electron density in the compounds. Moreover, MIC as well as the colorimetric assay for isolated solid compounds were tested. Moreover, molecular property and drug-likeness prediction of prepared compounds were estimated for conformity to the Lipinski rule of five. Furthermore, docking studies were applied for ligand and complexes on the active site of E. coli (PDB ID: 6F86), S. aureus (PDB ID: 3BL6) and C. albicans (PDB ID: 1IYL) receptors. Finally, cyclic voltammetry experiments were done in both absence/presence of H2AN in 0.1M KCl at fixed temperature (298.15 K) and a potential window (1 to -1v). Various concentrations of Cu(II) were used in 0.1M KCl to study the electrochemical behavior and calculate some thermodynamic parameters.

Exploring Pyrimidine-Based azo Dyes: Vibrational spectroscopic Assignments, TD-DFT Investigation, chemical Reactivity, HOMO-LUMO, ELF, LOL and NCI-RDG analysis

Theoretical computations of pyrimidine-based azo dyes were performed by the DFT approach using the B3LYP/6 − 31G(d,p) basis set. The molecules were optimized based on the same basis set by calculating the minimum energy. FMOs, DOS and GCRD were computed for kinetic stability and chemical reactivity of the selected compounds. The MEP surface was studied to locate nucleophilic and electrophilic attack zones. The energy gap was carefully studied for pyrimidine-based azo dyes. Vibrational spectroscopy was studied in the most prominent regions with respect to PED assignments. Similarly, the UV–Vis absorption technique was calculated using the TD-DFT approach in different solvent media. The electronic structure of each atom in a molecule was examined via the electron localization function (ELF) and localized orbital locator (LOL). Non-covalent interactions were explored using reduced density gradient analysis. The combination of experimental and theoretical data allowed us to correlate the structural modifications with the observed photophysical properties, facilitating the design of azo dyes with tailored characteristics. This work contributes to the fundamental understanding of azo dyes and offers a foundation for the development of new materials with enhanced photophysical and electronic properties.

A theoretical and electrochemical impedance spectroscopy study of the adsorption and sensing of selected metal ions by 4-morpholino-7-nitrobenzofuran

The selectivity of a novel chemosensor, based on a modified nitrobenzofurazan referred to as NBD-Morph, has been investigated for the detection of heavy metal cations (Co2+, Pb2+, Mg2+, Ag+, Cu2+, Hg2+, Ni2+, and Zn2+). The ligand, 4-morpholino-7-nitrobenzofurazan (NBD-Morph), was characterized using spectroscopic techniques including FT-IR and 1H NMR. Vibrational frequencies obtained from FT-IR and proton NMR (1H) chemical shifts were accurately predicted employing the density functional theory (DFT) at the B3LYP level of theory. Furthermore, an examination of the structural, electronic, and quantum chemical properties was conducted and discussed. DFT calculations were employed to explore the complex formation ability of the NBD-Morph ligand with Co2+, Pb2+, Mg2+, Ag+, Cu2+, Hg2+, Ni2+, and Zn2+ metal cations. The comparison of adsorption energies for all possible conformations reveals that NBD-Morph exhibits sensitivity and selectivity towards metal ions, including Pb2+, Cu2+, Ag+, and Ni2+. However, an assessment of their reactivity using QTAIM topological parameters demonstrated the ligand's greater complexation ability toward Cu2+ or Ni2+ than those formed by Pb2+ or Ag+. Additionally, molecular electrostatic potential (MEP), Hirshfeld surfaces, and their associated 2D-fingerprint plots were applied to a detailed study of the inter-molecular interactions in NBD-Morph-X (X = Pb2+, Cu2+, Ag+, Ni2+) complexes. The electron localization function (ELF) and the localized-orbital locator (LOL) were generated to investigate the charge transfer and donor-acceptor interactions within the complexes. Electrochemical analysis further corroborates the theoretical findings, supporting the prediction of NBD-Morph's sensory ability towards Ni2+ metal cations. In conclusion, NBD-Morph stands out as a promising sensor for Ni2+.

Experimental and theoretical studies of methyl 1-(2-chloroacetyl)-4-hydroxy-2,6-diphenyl-1,2,5,6-tetrahydropyridine-3-carboxylate: Insights from synthesis, spectroscopic, crystal structure, Hirshfeld surface, DFT, ELF, RDG, IRI, ADMET and docking studies

Methyl 1-(2-chloroacetyl)-4‑hydroxy-2,6-diphenyl-1,2,5,6-tetrahydropyridine-3-carboxylate (compound 2) was synthesized by the condensation of 3-carboxymethyl-2,6-diphenylpiperidine-4-one with chloroacetylchloride, and characterized by FT-IR spectroscopy. Further confirmation of the molecular structure was obtained by the single crystal X-ray diffraction (SC-XRD) technique. The study revealed that the piperidine ring adopts boat conformation with equatorial orientation of two phenyl rings at C-2 and C-6. Intermolecular contacts and hydrogen bonding interactions were explored by Hirshfeld surface and 2D fingerprint analyses, showing that the major contact were H∙∙∙H (57.7 %), C∙∙∙H/H∙∙∙C (14.2 %), O∙∙∙H/H∙∙∙O (15.3), Cl∙∙∙H/H∙∙∙Cl (7.1 %) and C∙∙∙Cl/Cl∙∙∙C (12.7 %). Intramolecular interaction was examined through the Radiant density gradient (RDG), Interaction region indicator (IRI), Electron localization function (ELF), and localized orbital locator (LOL) to understand hyperconjugration and π-electrons delocalization in the molecule. DFT studies such as structure optimization, HOMO-LUMO orbital analysis and molecular electrostatic potential were conducted for the title compound. The topology of the molecular arrangement and intermolecular interaction energies were determined through 3D energy framework analysis. Subsequently, the compound 2 was subjected to ADMET analysis to extend its scope of bioavailability. Molecular docking studies were then employed using the tyrosine kinase inhibitor, epidermal growth factor receptor (EGFR) enzymes (PDB ID: 4WKQ and 6JOL). The study revealed significant interactions between the title ligand structure and active sites of selected proteins complex.

The σ+π dual aromaticity of typical bi-tetrazole ring molecule TKX-50.

Two complexes of dihydroxylammonium 5,5'-bistetrazole-1,1'-diolate (TKX-50) were employed to evaluate the aromaticity of their tetrazole rings via deep analysis such as the electronic structure, the ZZ component of the natural chemical shielding tensor (NICSZZ) and component orbitals, localized orbital locator purely contributed by σ-orbitals (LOL-σ) and localized orbital locator purely contributed by π-orbitals (LOL-π), the anisotropy of the induced current density (AICD) and the ZZ component of iso-chemical shielding surface (ICSSZZ) of these tetrazole rings thereof. The conclusion shows: that all tetrazole rings and bi-tetrazole rings in complexes have strong σ and a comparable strength π double aromaticity; all these magnetic shields almost symmetrically increase from the central axis to the tetrazole ring atoms; tetrazole rings in complex II show a little stronger dual aromaticity than that in complex I mainly due to the different orientation of the fragment 2 encompassing two hydroxylamine groups resulting in different effects on the contributions of σ orbitals and π orbitals to total aromaticity of tetrazole rings thereof; the difference in aromaticity is fundamentally caused by the atoms O with stronger electron-withdrawing than atom N in fragment 2 interact with bi-tetrazole ring through O in complex I but through N in complex II.

Dynamic Covalent Bonds in the Ebselen Class of Antioxidants Probed by X-ray Quantum Crystallography.

Dynamic bonds are essential structural ingredients of dynamic covalent chemistry that involve reversible cleavage and formation of bonds. Herein, we explore the electronic characteristics of Se-N bonds in the organo-selenium antioxidant ebselen and its derivatives for their propensity to function as dynamic covalent bonds by employing high-resolution X-ray quantum crystallography and complementary computational studies. An analysis of the experimentally reconstructed X-ray wavefunctions reveals the salient electronic features of the Se-N bonds with very low electron density localized at the bonding region and a positive Laplacian value at the bond critical point. Bond orders and percentage covalency and ionicity estimated from the X-ray wavefunctions, along with localized orbital locator (LOL) and electron localization function (ELF) analyses show that the Se-N bond is unique in its closed shell-like features, despite being a covalent bond. Time-dependent DFT calculations simulate the cleavage of Se-N bonds in ebselen in the excited state, further substantiating their nature as dynamic bonds.

Solvation effects, structural, vibrational analysis, chemical reactivity, nanocages, ELF, LOL, docking and MD simulation on Sitagliptin

Sitagliptin is a medication used to manage type-2 diabetes. The present study investigates the experimental and theoretical results of Sitagliptin (SG). Density functional theory (DFT) calculations were used to determine optimized parameters at the B3LYP functional /6-31++G(d,p) basis set. In addition Time-dependent DFT is used to compute excited states of SG and SG-Ag6 and predict UV spectra. The electronic properties of silver nano cages containing SG have exhibited a notable enhancement. Natural bond orbital (NBO) analysis was also used to determine charge transfer within the molecule and stabilization energy. Electronic properties such as molecular electrostatic potential (MEP), frontier molecular orbital (FMO) analysis of SG and SG-Ag6 were investigated. The chemical significance of SG has been discussed using electron localization function (ELF) and local orbital locator functions (LOL) with contour images. Sitagliptin appears to have promise as a treatment for the chosen inhibitors, according to the docking binding affinities and the formation of a significant amount of hydrogen bonds. The molecular dynamics simulations were also performed using Gromacs 5.1.3 and discussed.

Exploring high-performance functionalized corannulene dimers: A DFT-based investigation for novel photovoltaic applications

Our current research is focused on designing new corannulene derivatives that exhibit significantly improved photovoltaic characteristics. These improvements comprise reduced excitation energy, a narrower optical band gap, enhanced light absorption capabilities, a high dipole moment, and reduced reorganization energies. Theoretical calculations of these parameters could pave the way for the creation of superior molecules for use in advanced solar cell technologies. In this work, we conducted a computational study (TD-DFT/CAM-B3LYP/6–311 +G) to examine the optical and electronic characteristics of a series of short-chain materials derived from a central core-based corannulene (A, B, C, D, and E-systems). The effect of various electron-donor side groups (such as: (1) 4-di(2-thienyl) thieno[3,4][1,2,5]-thiadiazole, (2) 2,2-Methyl Cyclopenta dithiophene, (3) Cyclopenta dithiophene, (4) 3,4-ethylene dioxythiophene, and (5) 4,6-di(2-thienyl)thieno[3,4-c][1,2,5]-thiadiazole (DTTTD)) on the electronic and photovoltaic properties of corannulene derivative as an electron-acceptor (such as radiation lifetime (τ), light harvesting efficiency (LHE), and maximum open circuit voltage (Voc)) was studied computationally. Also, the electron localization function (ELF) and the localized-orbital locator (LOL) analyses are used to discover the electronic localizations and delocalizations that occur after the addition of various ligands. The electronic and photovoltaic properties of each of the designed molecular structures were compared with P3HT as a reference. The obtained results showed that each of the designed molecular structures (especially the D-structure) is very efficient in the field of photovoltaics. Therefore, it seems that the D-structure can act (as a more suitable electron-donor than P3HT) together with phenyl-C61-butyric acid methyl ester (PC61BM) (as a good electron-acceptor) and improve the efficiency of solar cells.