Using a regioselectivity descriptor known as Fukui indices, this theoretical study examines the reactivity of cycloaddition processes of benzamide (PhCONH2) and chlorocarbonylsulfenyl chloride (ClCOSCl) at the level of base 6-311 G (d. p) by use of the DFT approach. Therefore, the attack of the sulfur atom on nitrogen and carbon on oxygen is kinetically more preferred than the assault of the sulfur atom on oxygen and carbon on nitrogen, as we have observed from our study. The electrophilic Δω difference between chlorocarbonylsulfenyl chloride and benzamide is 1.3726 eV. This indicates that the reaction under investigation has a polar nature (Δω > 1). on oxygen and carbon on nitrogen, as we have observed from our study. We have also studied the stereoselectivity and feasibility of these reactions from a thermodynamic and orbital point of view. The transition states of this reaction have been determined.

Oxadiazoles, a class of nitrogen-containing heterocycles, exhibit diverse applications in pharmaceuticals, industry, and other fields. This study employs Density Functional Theory (DFT) to investigate the structural, electronic, and spectroscopic properties of four oxadiazole isomers. The B3LYP functional and the 6-311G(d,p) basis set were used for calculations. Frontier orbital energies, energy gap, chemical reactivity descriptors, dipole moment, and thermodynamic properties were computed. Additionally, IR and UV spectra were analyzed. The results indicate significant variations in electronic and thermodynamic properties among the isomers. Isomer 4 demonstrated the highest stability and electrophilicity. The calculated IR and UV spectra were compared with available experimental and theoretical data. The study provides valuable insights into the structural and reactivity trends within the oxadiazole family, contributing to a deeper understanding of their potential applications.

This study focuses on the efficient synthesis of series of substituted 4-amino-6-(1H-benzimidazol-2-ylsulfanyl) benzene-1,3-dicarbonitrile derivatives synthesized from aldehydes, propanedinitrile, substituted thiols and catalyzed by ZnO nanoparticles (ZnONPs). All the synthesized compounds have been characterized using different spectroscopic techniques such as FT-IR, ¹H-NMR, C¹³-NMR and Mass. The compounds were evaluated for potential pharmacological applications, including antimicrobial, α-amylase inhibitory and anticancer activities. Computational calculations, DFT, in-silico molecular docking, and ADME-toxicologystudies were performed. ADMET studies indicated that all synthesized compounds adhered to Rule of five with good bioavailability. This research underscores the promising pharmacological prospects of the synthesized newbenzimidazole derivatives.

Methyl α-D-mannopyranoside (MAM) is a naturally occurring carbohydrate derivative that has gained attention in drug discovery due to its potential therapeutic applications, particularly as an antifungal agent. In this study, we employed a computational approach to investigate the interactions between MAM and two Candida albicans antifungal proteins, 1IYL and 1AI9, through molecular docking simulations. Furthermore, we performed a PASS (Prediction of Activity Spectra for Substances) analysis to predict MAM potential biological activities, explored the pharmacokinetic properties and ADMET (absorption, distribution, metabolism, excretion, and toxicity) profiles, and optimized the MAM using the density functional theory (DFT) method. The molecular docking results revealed favorable binding interactions between MAM and the active sites of the 1IYL and 1AI9 proteins, suggesting potential antifungal activity. Additionally, the ADMET profiles indicated low toxicity and suitable drug-like properties, such as moderate metabolic stability and minimal risk of adverse effects. Furthermore, DFT optimization was performed to investigate the molecular geometry and electronic properties of MAM. The optimization results provided valuable information on the stability and reactivity of MAM, enabling a better understanding of its chemical behavior and potential modifications for enhanced activity. Finally, PASS prediction was employed to evaluate MAM's potential biological activities beyond its antifungal properties. The analysis revealed several potential activities, including antibacterial, antiviral, and immunomodulatory effects, expanding the scope for future research and therapeutic applications. In conclusion, this computational study sheds light on the molecular interactions, pharmacokinetic properties, ADMET profiles, DFT optimization, and PASSES predictions of MAM. These findings highlight the potential of MAM as a promising antifungal agent with favorable pharmacological properties.

In this work, two organic materials as dyes, namely, methylene blue (MB) and methyl red (MR), have been proposed to play the role of the electron donor in organic photovoltaic (OPV) cells. We use the PCBM as a well-known electron acceptor. The density functional theory (DFT) method has been used to determine the electrostatic potential and the frontier molecular orbitals (FMO), of the methylene blue (MB) and the methyl red (MR) compounds. Nonlinear optical (NLO) descriptors have been determined for the two compounds. The potential energy surface analysis has been performed by the DFT method using the exchange and correlation of Becke, Lee, Yang, and Parr Gradient Corrected Functional (B3LYP) with the standard 6-31G(d) base. We have performed another theoretical study using quantum time-dependent density functional theory (TD-DFT) on both MB and MR as organic dyes to determine their UV-Vis spectra. The results of the energy gap, chemical hardness, dipole moment, and hyperpolarizability show that MB may be chemically more reactive Than MR. The present work has proposed a bilayer organic photovoltaic (OPV) cell to contribute to the valorization of the two dyes as solar materials. The developed photovoltaic cell project has used electrical and energetic parameters that can describe the OPV cell based on ([MB or MR]: PCBM). Open-circuit voltage (Voc), excitation energy, and oscillator strength have been theoretically determined. The results of the present work showed a remarkably high open circuit voltage, especially in the case of methyl red (1.55 V) more than in the case of the methylene blue (0.84 V) so that both of the two dyes can be a good candidate for organic solar cells.

The FTIR and Raman spectra of dopamine were also recorded in the spectral region 20 - 4000 cm^-1 and 400 - 4000 cm^-1 respectively. The optimized molecular geometry and fundamental vibration frequencies are interpreted using structural optimizations based on the DFT method. The B3LYP / 6-311G (d, p) was used to determine the calculations of the chemical descriptor. The dopamine (DA) molecule can acquire a maximum charge of 0.513 eV from its environment. To understand the molecular interactions of Dopamine, the MEP is a crucial tool. Nonlinear optical descriptors (NLO) and the lengths, bond angles are also determined by DFT and MP2 methods. The DFT method was used to determine the chemical shifts of ¹H and ¹³C of the product. These constants have been calculated by employing the GIAO (Gauge-Including-Atomic-Orbit), CSGT (Continuous Set of Gauge Transformations) and IGAIM (Individual Gauges for Atoms In Molecules) methods at the B3LYP/6-311G (d, p). The comparison of the theoretical chemical shifts with the experimental ones shows that the CSGT method is the best.

The FT-IR spectrum of salicylic acid (SA) was studied in the region 10-4000 cm-1. The optimized molecular geometry and fundamental vibration frequencies are interpreted using structural optimizations based on the Functional Density Theory (DFT) method. Additionally, we used B3LYP / 6-311G (d, p) to determine the chemical descriptor, the ionization potential (I), the electron affinity (A), the chemical potential (μ), the chemical hardness (η). Nonlinear optical descriptors (NLO) such as dipole moment (μ), polarizability (α), first hyperpolarizability (β) and second hyperpolarizability (γ), 3D maps of HOMO and LUMO orbitals, lengths and Bond angles of salicylic acid isomers are also determined by both DFT and MP2 (The Møller-Plesset theory of order 2 perturbation) methods. The overall descriptors and the non-linear optical properties confirmed that salicylic acid is the reactive molecule and para-hydroxybenzoic acid is the stable molecule. An electrostatic molecular potential (MEP) study was also performed to determine the reactivity of molecules.

This paper is interested in mechanism of lactic acid (LA) adsorption and dehydration into acrylic acid (AA) over tin and iron beta zeolite (Sn- and Fe-BEA) catalysts. The electronic structure of clusters was calculated by ab initio density functional theory (DFT) method. The M₂Si₁₂O₃₉H₂₂ (hierarchical zeolite) and M₂Si₂₂O₆₄H₃₂ (ideal zeolite) clusters (M=Al, Si, Sn) were used in the LA dehydration reaction. The stabilization of the dimeric complex M-O_b-M (where M= Sn or Fe) in the BEA, ideal and hierarchical structure, was investigated. Possible modes of interaction of lactic acid with different cations (Si, Al, Fe or Sn) in the BEA zeolite framework as well as with added iron and tin dimers were considered. The interaction of lactic acid was only observed above the M-O_b-M dimer. The direct mechanism of lactic acid dehydration into acrylic acid was found over metal M-O_b-M dimers deposited at the BEA zeolite.

The process of racemisation of atropisomeric biaryls was modelled by means of DFT calculations at an advanced B3LYP/6-31G* theoretical level. Thus, the detailed protocol of determination of the racemisation rate presented herein provides a practical prediction tool for elucidation of the configurational stability of atropisomers.

The predominant tautomeric forms of N1–H, N2–H of 5-(2,6-dimethyl- and 5-(2,6-diisopropylphenoxy)-(1H)-tetrazoles were analyzed at B3LYP method using 6-311G(d,p) basis set in the gas phase. The N1–H form of tetrazoles was found to be more stable than N2–H form in both solid and gas phases. Crystal structures of both tetrazoles show an intermolecular H-bond between N1-H and N4 atom of other tetrazole space. The hydrogen bonds between each tautomer of tetrazoles were evaluated at B3LYP/6-311G(d,p) level. The geometrical parameters and spectral data of tetrazoles and their variation were studied in both solid and gas phases.