A Schiff base 4-chloro-2-((pyridin-3-ylimino)methyl)phenol: crystal structure details, computational study, proteolytic properties, molecular docking, in vivo toxicity and in vitro antibacterial activity

Exploration of the synthesis, crystal structure, Hirshfeld surface analysis, binding properties, antibacterial activities, and molecular docking of a Schiff base nickel (II) Complex

Tautomeric, spectroscopic, electronic and NLO analyses of purpald (4-amino-3-hydrazino-5-mercapto-1,2,4-triazole)

Sonication-assisted synthesis of new Schiff bases derived from 3-ethoxysalicylaldehyde: Crystal structure determination, Hirshfeld surface analysis, theoretical calculations and spectroscopic studies

A zinc-based pyrazole halide, [ZnCl2(η1-4BrPz)2] (4BrPz = C3H3BrN2 = 4-Bromopyrazole) was synthesized and characterized by X-ray diffraction, IR spectroscopy, and Hirshfeld surface analysis. The compound crystallizes in a monoclinic system with two non-equivalent Zn(ii) environments stabilized by halogen–halogen and π-interactions. DFT, ELF, and NCI analyses highlight the key role of Br⋯Br, Br⋯Cl, π-stacking, and hydrogen-bonding contacts in stabilizing the structure. Thermal studies (TGA/DSC) confirm good stability and a well-defined decomposition pathway. Molecular docking and in silico ADME predictions (SwissADME) were performed to evaluate the pharmacokinetic profile and biological potential of the compound, revealing favorable drug-likeness and strong binding affinity toward DNA gyrase and chitin synthase. In vitro tests reveal moderate, concentration-dependent antibacterial activity against eight pathogenic strains, with inhibition zones increasing from 3.9–6.3 mm at 0.5 µg mL−1 to 14.7–16.8 mm at 2 µg mL−1. Pseudomonas aeruginosa and Micrococcus luteus were the most sensitive, while Bacillus cereus and Salmonella typhi were less affected. The tested compound [ZnCl2(η1-4BrPz)2] exhibited dose-dependent antibacterial activity against all evaluated strains, with MIC values ranging from 0.45 to 2.10 µg mL−1 and MBC values from 0.87 to 3.74 µg mL−1. In comparison, the free ligand (4BrP) showed considerably higher MIC (2.89–7.84 µg mL−1) and MBC (11.7–19.76 µg mL−1) values, indicating much weaker antibacterial activity. The strongest activity of the complex was observed against Escherichia coli and Bacillus cereus, while Salmonella typhi and Pseudomonas aeruginosa were less sensitive. MBC/MIC ratios for the complex were below 4 for all strains, confirming a bactericidal effect as compared to 4BrP. These results identify [ZnCl2(η1-4BrPz)2] as a structurally robust and biologically promising zinc complex for future antimicrobial development.

Synthesis of two new Schiff bases; crystal structure, Hirshfeld surface analysis, density functional theory and molecular docking

This study presents the synthesis and thorough characterisation of a hydrazine-hydroxy-pyran-2-one derivative referred to as compound (L1 : 3, 3′- [(1E.2E)-hydrazine-1, 2-diylidene-dieth-1-yl-1-ylidene] bis(4-hydroxy-6-methyl-2H-pyran-2-one). Structural elucidation using UV-vis, FT-IR and single crystal X-ray diffraction (SC-XRD) confirmed tautomeric forms of L1 . The SC-XRD analysis revealed a bi-zwitterionic form (BZL1 ), stabilised by the intramolecular proton transfer between two enol units and azine tautomerism. The planar molecular structure, supported by XRD, DFT and Hirshfeld surface analysis, showed charge-assisted hydrogen bonds [N+−H…O−] forming S(6) ring motifs. Crystals were stabilised by C-H…O hydrogen bonds and π-π stacking, analysed through Hirshfeld surfaces and 2D fingerprint plots. Compound L2 : 3-[(1E)-1-(9H-fluoren-9-ylidenehydrazinylidene)ethyl]-4-hydroxy-6-methyl-2H-pyran-2-one), is illustrated in this paper to compare two derivatives of dehydroacetic acid (DHA) and to enrich this study. Molecular docking revealed binding affinities of hybrid compounds with target proteins. DFT and TD-DFT analyses examined structural, electronic and optical properties, aligning well with experimental data. BZL1 exhibited higher electronic hardness (3.632 eV) than L2 (3.506 eV). Variations in α, Δα and ρ values were observed, with L1 showing stronger γ(0; 0, 0, 0) and γ(−ω; ω, 0, 0) while L2 excelled in γ(−2ω; ω, ω, 0). Consequently, these results highlight the potential of these compounds as promising candidates for use in third-order nonlinear optical applications.

A new series of transition metal complexes of bidentate Schiff base compound derived from 2‐hydroxy‐1‐(2‐methoxyethylimino)‐naphthalene (HL) were synthesized and characterized using elemental analysis, Fourier transform infrared spectroscopy (FT‐IR), and UV–vis spectroscopies. X‐ray single crystal structures of Zn(II), Mn(III), and Co(III) complexes (1–4) have also been determined, and it was indicated that these Zn(II) and Co(III) complexes (1, 4) are in an octahedral geometry. Whereas, it was found that the Zn complex (2) is in quite a regular tetrahedral environment. Also, the Mn center in complex (3) is ligated by two azomethine nitrogen atoms, two ligand oxygen atoms, and one Cl atom of metal salt forming five coordinated tetragonal pyramid geometry around the Mn atoms. The cyclic voltammetry of the complexes specifies an irreversible redox behavior for all complexes (1–4). Next, DFT/B3LYP theoretical method was used to determine the optimal geometrical configurations and comparison between experimental and theoretical data, as well as for calculations of molecular electrostatic potential, highest‐occupied molecular orbital (HOMO)‐lowest‐unoccupied molecular orbital (LUMO) energy values of selected compounds. The study of non‐covalent interactions was done by Hirshfeld surface analysis using CrystalExplorer program. Furthermore, molecular docking inspection was carried out to study the binding affinity of the tested complexes towards protein B‐cell lymphorna (PDB ID: 4LXD). Using the results obtained from the molecular docking and the summarized interaction of the binding processes, these structures show the validity of effective inhibition against liver cancer.

Molecular docking, Hirshfeld surface, structural, spectroscopic, electronic, NLO and thermodynamic analyses on novel hybrid compounds containing pyrazole and coumarin cores

New thioether-hydrazide based ONS donor Schiff base and its Pd(II) complex: Synthesis, crystal structure, thermal analysis, hirshfeld surface analysis, quantum chemical studies and molecular docking

Synthesis, crystal structure, DFT calculations, Hirshfeld surface analysis and molecular docking studies of a new manganese complex

Theoretical and computational insight into the supramolecular assemblies of Schiff bases involving hydrogen bonding and C[sbnd]H…π interactions: Synthesis, X-ray characterization, Hirshfeld surface analysis, anticancer activity and molecular docking analysis

Conformational stability, quantum computational, spectroscopic, molecular docking and molecular dynamic simulation study of 2-hydroxy-1-naphthaldehyde

Herein, we report the preparation of methyl 6-methyl-4-(4-nitrophenyl)-2-oxo-1,2-dihydropyrimidine-5-carboxylate 2, obtained by the regioselective oxidative dehydrogenation of the dihydropyrimidine derivative 1 in the presence of cerium ammonium nitrate. The structure of compound 2 was investigated by single-crystal X-ray diffraction (SC-XRD), which allowed the determination of its tautomeric form. Moreover, the presence of non-covalent interactions and their impact on the crystal structure were analyzed. To better characterize the intermolecular contacts, the Hirshfeld surface and enrichment ratio analyses were performed. Furthermore, the antimycotic activity of compounds 1 and 2 was investigated against Candida albicans, Aspergillus flavus, and Aspergillus niger, and their efficacy was compared to that of fluconazole. Computational investigations on the putative target of the compounds provided insights to explain the better activity of 2 with respect to its synthetic precursor.

ZnFe2O4 Assisted Facile Green Synthesis, Structural Conformation, In-Silico and In-vitro Antimicrobial Exploration of some Piperidine Moiety Schiff's Bases

1H-Indole-3-carbaldehyde (1H-I3A) was investigated experimentally by NMR (1H-NMR and 13 C-NMR in solution form), FT-Raman, FT-IR, UV-Visible and quantum chemically by DFT approach. 3 D and 2 D surface analysis was carried by Hirshfeld surface analysis. The B3LYP method and the 6-311++G(d,p) basis set were used to optimize the molecular structure and vibrational modes. Optimized binding parameters and experimental binding parameters are in good agreement. VEDA (Vibrational Energy Distribution analysis) successfully carried out and complete tasks for the distribution of potential energy. 1H-NMR and 13 C-NMR shifts were estimated with GIAO method and the results compared with experimental spectra. The TDDFT method and the PCM solvent model were used for the analysis of electronic properties such as UV-Vis (in the gas phase, methanol and DMSO) and compared with the experimental UV-Vis spectra. The HOMO/LUMO energy results underscore that sufficient charge transfer has taken place within the molecule. Studies of donor-acceptor connections were performed using NBO analysis. The MEP surface analysis was performed and charge distribution was demonstrated. The degree of relative localization of electrons was analyzed using the FLF diagram. The Fukui functional analysis to find possible points of attack for various substituents. Molecular electrostatic potential (MEP) was created and 3-D color representation shows reactive sites. Study of donor-acceptor interconnections were done via NBO analysis. The biological study like molecular docking was done with 7 different receptors to find the best ligand-protein interactions and drug similarities.