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In this work, a thiazole derivative, 5-(5-nitro furan-2-ylmethylen), 3-N-(2-methoxy phenyl),2-N'-(2-methoxyphenyl) imino thiazolidin-4-one (abbreviated by NF2MT), was characterized through Fourier transform infrared, UV–vis, 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. Besides, a complete and detailed vibrational assignment have been achieved by means of density functional theory (DFT) calculations using the B3LYP theory and the 6 311G(d,p) basis set. Based on the electron density distribution, reduced density gradient and atoms-in molecules analyses have been performed to describe and identify the intra- and intermolecular interactions within the molecule. Non-covalent interactivities between non-bonded atoms were also characterized. In addition, the frontier molecular orbitals and global chemical reactivity descriptors of NF2MT were further investigated using DFT, revealing the most important electronic properties of the compound. The TD-DFT method at CAM-B3LYP/6-311G(d,p) level with the chloroform solvent and polarized continuum model was applied to obtain optical behavior as well as the electronic transitions for the molecule. On the other hand, molecular properties such as atomic charges (Mulliken and NBO) and molecular electrostatic potential were calculated to locate the most reactive sites in the molecule that promote hydrogen bond formation. Molecular docking studies were also carried out to predict and display binding sites of NF2MT with its target protein. The biological activity was tested with acetylcholinesterase and butyrylcholinesterase. [ABSTRACT FROM AUTHOR]

In this work, 2-thioxo -3 N-(2-ethoxyphenyl -5[4′-methyl -3′N-(2′-ethoxyphenyl) thiazol-2′(3′H)-ylidene] thiazolidin-4-one (E2Th2) was synthesized and its molecular structure determined by FT-IR, UV-Vis and NMR spectroscopic techniques along with a single crystal X-ray diffraction study. Quantum chemical calculations were performed to better understand its structural, spectroscopic and electronic properties such as HOMO and LUMO energy gap, MEP and global reactivity descriptors. Theoretical calculations were performed using density functional theory (DFT) based on the B3LYP/6-311G (d,p). Vibrational frequencies were assigned on the basis of PED and electronic transitions are calculated according to time-dependent density functional theory (TD-DFT). The HOMO and LUMO analysis are used to determine the charge transfer within the molecule. The NLO activity evaluation was based on the determination of the dipole moment, polarizability (α), first-order hyperpolarizability (β) and the second-order hyperpolarizability (γ) which were calculated using the same level of theory. The hyper-hardness descriptor (Γ) was explored and correlated with the NLO properties. Additionally, the stability of the molecule occurring from hyper-conjugative interaction, intramolecular hydrogen bond and charge delocalization were quantified using NBO analysis. The repulsive, attractive, and van der Waals strong and weak interactions were revealed by RDG and HS analyses. Finally, results have shown that the title compound can be used as attractive future NLO material. [ABSTRACT FROM AUTHOR]

• New benzimidazole derivative was synthesized and characterized by IR and (1H, 13C) NMR. • Its 3D structure has been obtained by SC-XRD, B3LYP and B3LYP-GD3(BJ). • The intermolecular interactions were explored using the hirshfeld surface. • The NLO parameters of the title compound and the benzimidazole ring were evaluated. • Biological behavior was studied theoretically using molecular docking. In this study, we report the synthesis of (Z)-3-((Z)-3-phenylallylidene)benzo[4,5]imidazo[1,2-c]thiazole-1(3H)-thione (ThBMT). This compound belongs to an important group of molecules containing two or more heterocyclic moieties. ThBMT was experimentally characterized using IR and NMR spectroscopy. The absolute 3D structure of ThBMT was determined by single-crystal X-ray diffraction, revealing crystallization in the monoclinic space group P21/c with four molecules in the unit cell. First principle theoretical calculations were carried out via the Density Functional Theory (DFT) method with B3LYP and B3LYP-GD3(BJ) functionals using the 6–311++G(d, p) basis set. The geometrical parameters of ThBMT were analyzed and compared to those of optimization, which were found to be consistent. The crystal packing and their intermolecular interactions were studied by Hirshfeld surface analysis, revealing that the most common interactions were C-H⋅⋅⋅N and C-H⋅⋅⋅S. Furthermore, theoretical vibrational wavenumbers were computed, assigned, and compared to the experimental ones. The (1H, 13C) NMR chemical shifts were calculated and compared with experimental values. The compound's nonlinear optical (NLO) properties were also investigated to understand its potential applications in optoelectronics, and compared to those of the benzimidazole fragment. The results showed promising NLO characteristics. Molecular docking and in silico ADMET studies were reported to highlight the biological behavior of ThBMT, indicating anti-tuberculosis properties, and anti-tumor activities against HeLa and HepG2 cancer cell lines. [Display omitted] [ABSTRACT FROM AUTHOR]

• The optimized geometry is computed and spectroscopic properties of DBQA using B3LYP methods. • Experimentally and Theoretically calculated by FT-IR, UV–Vis, NMR spectrum of DBQA. • Hirshfeld surface analysis and fingerprint plots were generated. • The nonlinear optical properties have been evaluated for the different conformation. • Molecular docking of MBQA against HMGCS2 main protease (Mpro) protein. In this study, we present the synthesis and characterization of a novel organic compound, (E)-N'-(3-methoxybenzylidene)-2-(quinolin-8-yloxy) acetohydrazide. Our characterization includes single crystal X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and UV–visible spectroscopy. We also conducted Hirshfeld surface (HS) analysis to investigate intermolecular interactions. The compound crystallizes in the triclinic system with space group P −1. We employed density functional theory (DFT) with the B3LYP function and the 6–311 G (d, p) basis set to calculate its electronic properties. Additionally, we explored its nonlinear optical (NLO) behavior, determining the electric dipole moment (μ), polarizability (α), and hyperpolarizability (β), second-order hyperpolarizabilities (γ) using the same basis set. To evaluate the NLO properties of MBQA, we conducted frontier molecular orbitals (FMO) analysis, examined HOMO-LUMO energies, determined the energy band gap, studied the density of states (DOS), and assessed global chemical reactivity descriptors. We also performed a molecular electrostatic potential (MEP) simulation to identify optimal sites for both electrophilic and nucleophilic attacks. Our analysis further included a reduced density gradient (RDG) analysis to investigate various types of intermolecular interactions in MBQA, such as repulsive, attractive, and Van der Waals interactions while also distinguishing between strong and weak interactions. To understand the molecular stability and interactions, we conducted natural bond orbital (NBO) analysis, which provided insights into hyperconjugative interactions, charge delocalization and electron density ED among the molecular components. Finally, we assessed the biological activity of the MBQA molecule by predicting its potential pharmacological activities using the prediction of activity spectra for substances (PASS) and conducting molecular docking analyses. This comprehensive study provides valuable insights into the structural, electronic, and biological properties of (E)-N'-(3-methoxybenzylidene)-2-(quinolin-8-yloxy) acetohydrazide (MBQA). [Display omitted] [ABSTRACT FROM AUTHOR]

• The experimental structure was characterized by FT-IR, UV–Vis and NMR. • The optimized geometry of FBID molecule was computed and its spectroscopic properties were examined. • The nonlinear optical properties have been evaluated for the different conformations of the FBID molecule. • MEP and energy gaps of frontier molecular orbitals (HOMO–LUMO) have been calculated. • Hirshfeld surface analysis and fingerprint plots were carried out. In a previous study, the 1-(4-fluorobenzyl)-5-bromolindolin-2,3‑dione (FBID) molecule was synthesized by adding isatin and K 2 CO 3 to acetonitrile, followed by the addition of 4-fluorobenzyl chloride. The resulting mixture was filtered, concentrated, then solidified with n-hexane, and recrystallized in water. In the present study, a combination of theoretical and experimental methods is employed to evaluate and understand the structural and vibrational properties of FBID: FT-IR, UV–Vis as well as 1H and 13C NMR chemical shifts using GIAO approach. All calculations were performed applying the DFT method, with B3LYP functional and 6–311G(d,p) basis set. The HOMO-LUMO energy gap revealed a good charge transfer interaction in FBID molecule. Also, the HOMO and LUMO energies have been exploited to describe the global chemical reactivity. At the same method and level, it has been demonstrated that the studied compound has NLO properties. The estimated NBO, atomic charges and the molecular electrostatic potential map indicated that the sites around the oxygen atoms of the FBID molecule are the most reactive. The contribution of intermolecular interactions was analysed via Hirshfeld surface analysis. In order to identify the different types of all possible interactions in our system, the reduced density gradient (RDG) method was used to characterize and evaluate the nature of these interactions as strong repulsion (steric effect), strong attraction (hydrogen bond), or weak interaction (Van der Waals). [Display omitted] [ABSTRACT FROM AUTHOR]