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The goal of this study was to synthesize and evaluate new antimicrobial compounds. We specifically focused on the development of 2,5-disubstituted tetrazole derivatives containing the O-methyl-2,3-O-isopropylidene-(D)-ribofuranoside groups through N-alkylation reactions. The synthesized compounds were characterized using 1 H and 13 C nuclear magnetic resonance (NMR) spectroscopy. Their antibacterial activity was tested against Pseudomonas aeruginosa , Escherichia coli , Streptococcus fasciens , and Staphylococcus aureus . Density functional theory (DFT) was applied to examine the electronic properties, including the highest occupied molecular orbital (HOMO)-least unoccupied molecular orbital (LUMO) gap, hardness, softness, density of states (DOS), and molecular electrostatic potential. Additionally, crystal structure modeling of protein 7AZ5 was performed to study the binding affinities through hydrophobic interactions and hydrogen bonding. Molecular dynamics simulations were carried out for 100 ns and OPLS_2005 force field re performed to investigate the stability of 3c and 5c into 7AZ5 binding site. Root-mean-square deviation (RMSD), root mean square fluctuation (RMSF), and intermolecular interactions analysis showed that these two compounds may gave relative stability into the 7AZ5 binding site. Several of the N-ribofuranosyl tetrazole derivatives synthesized displayed a strong antibacterial activity. Compounds 1c and 5c were particularly effective, with a minimum inhibitory concentration (MIC) of 15.06 μM and 13.37 μM, respectively, against E. coli and S. aureus both surpassing the efficacy of chloramphenicol (19.34 μM) and ampicillin (28.62 μM). These compounds also displayed the highest binding energies in protein modeling, indicating strong interactions with the DNA polymerase sliding clamp of E. coli . Compounds 1c and 5c show promise as potent antibacterial agents with notable chemical stability and favorable binding profiles. These findings suggest that these derivatives may serve as valuable leads for the development of new antimicrobial drugs., Competing Interests: The authors declare no competing financial interest., (© 2025 The Authors. Published by American Chemical Society.)

The objective of the study was to synthesize tetrazole molecules featuring nitro groups positioned at the para and meta locations. We aimed to assess their effectiveness in inhibiting corrosion of mild steel in a 1 M HCl solution at 298 K. Tetrazoles with 2,5-disubstitution were created using [3 + 2] cycloaddition and N-alkylation techniques, with a particular emphasis on synthesizing molecules that contain nitro groups. Tafel polarization experiments, which employ the polarization curve approach, were used to assess the effectiveness of corrosion inhibition. Furthermore, quantum chemical calculations using density functional theory and Monte Carlo simulations were used to investigate the connection between the molecular structure of the produced tetrazoles and their efficacy as corrosion inhibitors. The results showed that the 2,5-disubstituted tetrazoles exhibited high corrosion inhibition efficiencies, with compounds P1 and P2 achieving inhibition rates of 82.7 and 94.6%, respectively, at a concentration of 10 -4 M. The Tafel polarization results confirmed the effectiveness of the synthesized tetrazoles, while the theoretical calculations supported the experimental outcomes, establishing a strong correlation between their molecular structure and corrosion inhibition performance., Competing Interests: The authors declare no competing financial interest., (© 2025 The Authors. Published by American Chemical Society.)

The presence of pollutants in water sources, particularly dyes coming by way of the textile industry, represents a major challenge with far-reaching environmental consequences, including increased scarcity. This phenomenon endangers the health of living organisms and the natural system. Numerous biosorbents have been utilized for the removal of dyes from the textile industry. The aim of this study was to optimize discarded Zygophyllum gaetulum stems as constituting an untreated natural biosorbent for the efficient removal of C.I. Direct Black 80, an azo textile dye, from an aqueous solution, thus offering an ecological and low-cost alternative while recovering the waste for reuse. The biosorbent was subjected to a series of characterization analyses: scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET) method, X-ray diffraction (XRD), and infrared spectroscopy (IR) were employed to characterize the biosorbent. Additionally, the moisture and ash content of the plant stem were also examined. The absorption phenomenon was studied for several different parameters including the effect of the absorption time (0 to 360 min), the sorbent mass (3 to 40 g/L), the pH of the solution (3 to 11), the dye concentration (5 to 300 mg/L), and the pH of the zero-charge point (2-12). Thermodynamic studies and desorption studies were also carried out. The results showed that an increase in plant mass from 3 to 40 g/L resulted in a notable enhancement in dye adsorption rates, with an observed rise from 63.96% to 97.08%. The pH at the zero-charge point (pHpzc) was determined to be 7.12. The percentage of dye removal was found to be highest for pH values ≤ 7, with a subsequent decline in removal efficiency as the pH increased. Following an initial increase in the amount of adsorbed dye, equilibrium was reached within 2 h of contact. The kinetic parameters of adsorption were investigated using the pseudo-first-order, pseudo-second-order and Elovich models. The results indicated that the pseudo-first-order kinetic model was the most appropriate for the plant adsorbent. The isotherm parameters were determined using the Langmuir, Frendlich, Temkin, and Dubinin-Radushkevich models. The experimental data were more satisfactory and better fitted using the Langmuir model for the adsorption of dye on the plant. This study demonstrated that Zygophyllum gaetulum stems could be employed as an effective adsorbent for the removal of our organic dye from an aqueous solution.

The title mol-ecule, C 25 H 23 BrN 2 O 2 , adopts a cup shaped conformation with the distinctly ruffled imidazolidine ring as the base. In the crystal, weak C-H⋯O hydrogen bonds and C-H⋯π(ring) inter-actions form helical chains of mol-ecules extending along the b -axis direction that are linked by additional weak C-H⋯π(ring) inter-actions across inversion centres. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (51.0%), C⋯H/H⋯C (21.3%), Br⋯H/H⋯Br (12.8%) and O⋯H/H⋯O (12.4%) inter-actions. The volume of the crystal voids and the percentage of free space were calculated to be 251.24 Å 3 and 11.71%, respectively, showing that there is no large cavity in the crystal packing. Evaluation of the electrostatic, dispersion and total energy frameworks indicate that the stabilization is dominated by the dispersion energy., (© Lamssane et al. 2024.)

The benzimidazole moiety in the title mol-ecule, C 19 H 25 N 5 O, is almost planar and oriented nearly perpendicular to the triazole ring. In the crystal, C-H⋯O hydrogen bonds link the mol-ecules into a network structure. There are no π-π inter-actions present but two weak C-H⋯π(ring) inter-actions are observed. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (62.0%), H⋯C/C⋯H (16.1%), H⋯N/N⋯H (13.7%) and H⋯O/O⋯H (7.5%) inter-actions. Evaluation of the electrostatic, dispersion and total energy frameworks indicate that the stabilization is dominated via the dispersion energy contributions in the title compound., (© El Atrassi et al. 2024.)

This study reports the synthesis of 2-thioxo-1,3-dithiol-carboxamides ( TDTCAs ) under mild conditions at room temperature using HBTU as a coupling agent, which significantly improved amide bond formation. The synthesized compounds were characterized using several analytical techniques, including 1 H and 13 C NMR spectroscopy, and HRMS, confirming their intended structures and structural integrity. A DFT computational study at the B3LYP/6-31G(d,p) level was conducted on the four synthesized compounds to compare their electronic properties and molecular structures. The results showed that these compounds demonstrated antispasmodic effects on jejunum contractions. Molecular docking revealed that compounds c and d displayed the highest docking scores on potassium and voltage-gated calcium channels and adrenergic receptors. In summary, compounds c and d exhibit antispasmodic effects, potentially blocking alpha-adrenergic receptors and calcium channels, thus providing a scientific basis for their potential use in treating gastrointestinal disorders.

This study focuses on synthesizing a new series of isoxazolinyl-1,2,3-triazolyl-[1,4]-benzoxazin-3-one derivatives 5a - 5o . The synthesis method involves a double 1,3-dipolar cycloaddition reaction following a "click chemistry" approach, starting from the respective [1,4]-benzoxazin-3-ones. Additionally, the study aims to evaluate the antidiabetic potential of these newly synthesized compounds through in silico methods. This synthesis approach allows for the combination of three heterocyclic components: [1,4]-benzoxazin-3-one, 1,2,3-triazole, and isoxazoline, known for their diverse biological activities. The synthesis procedure involved a two-step process. Firstly, a 1,3-dipolar cycloaddition reaction was performed involving the propargylic moiety linked to the [1,4]-benzoxazin-3-one and the allylic azide. Secondly, a second cycloaddition reaction was conducted using the product from the first step, containing the allylic part and an oxime. The synthesized compounds were thoroughly characterized using spectroscopic methods, including 1 H NMR, 13 C NMR, DEPT-135, and IR. This molecular docking method revealed a promising antidiabetic potential of the synthesized compounds, particularly against two key diabetes-related enzymes: pancreatic α-amylase, with the two synthetic molecules 5a and 5o showing the highest affinity values of 9.2 and 9.1 kcal/mol, respectively, and intestinal α-glucosidase, with the two synthetic molecules 5n and 5e showing the highest affinity values of -9.9 and -9.6 kcal/mol, respectively. Indeed, the synthesized compounds have shown significant potential as antidiabetic agents, as indicated by molecular docking studies against the enzymes α-amylase and α-glucosidase. Additionally, ADME analyses have revealed that all the synthetic compounds examined in our study demonstrate high intestinal absorption, meet Lipinski's criteria, and fall within the required range for oral bioavailability, indicating their potential suitability for oral drug development.

The benzimidazole entity of the title mol-ecule, C 17 H 21 N 5 O, is almost planar (r.m.s. deviation = 0.0262 Å). In the crystal, bifurcated C-H⋯O hydrogen bonds link individual mol-ecules into layers extending parallel to the ac plane. Two weak C-H⋯π(ring) inter-actions may also be effective in the stabilization of the crystal structure. Hirshfeld surface analysis of the crystal structure reveals that the most important contributions for the crystal packing are from H⋯H (57.9%), H⋯C/C⋯H (18.1%) and H⋯O/O⋯H (14.9%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the most dominant forces in the crystal packing. Evaluation of the electrostatic, dispersion and total energy frameworks indicate that the stabilization of the title compound is dominated via dispersion energy contributions. The mol-ecular structure optimized by density functional theory (DFT) at the B3LYP/6-311 G(d,p) level is compared with the experimentally determined mol-ecular structure in the solid state., (© El Atrassi et al. 2024.)

In the title mol-ecule, C 21 H 23 N 3 O 3 , the imidazolidine ring slightly deviates from planarity and the morpholine ring exhibits the chair conformation. In the crystal, N-H⋯O and C-H⋯O hydrogen bonds form helical chains of mol-ecules extending parallel to the c axis that are connected by C-H⋯π(ring) inter-actions. A Hirshfeld surface analysis reveals that the most important contributions for the crystal packing are from H⋯H (55.2%), H⋯C/C⋯H (22.6%) and H⋯O/O⋯H (20.5%) inter-actions. The volume of the crystal voids and the percentage of free space were calculated to be 236.78 Å 3 and 12.71%, respectively. Evaluation of the electrostatic, dispersion and total energy frameworks indicates that the stabilization is dominated by the nearly equal electrostatic and dispersion energy contributions. The DFT-optimized mol-ecular structure at the B3LYP/6-311 G(d,p) level is compared with the experimentally determined mol-ecular structure in the solid state. Moreover, the HOMO-LUMO behaviour was elucidated to determine the energy gap., (© Lamssane et al. 2024.)

The title mol-ecule, [Fe 2 (C 5 H 5 ) 2 (C 23 H 17 ClN 2 )]·C 3 H 7 NO, is twisted end to end and the central N/C/N unit is disordered. In the crystal, several C-H⋯π(ring) inter-actions lead to the formation of layers, which are connected by further C-H⋯π(ring) inter-actions. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (60.2%) and H⋯C/C⋯H (27.0%) inter-actions. Hydrogen bonding, C-H⋯π(ring) inter-actions and van der Waals inter-actions dominate the crystal packing., (© Sghyar et al. 2024.)

The title compound, C 16 H 17 N 3 O 3 , is racemic as it crystallizes in a centrosymmetric space group ( P ), although the trans disposition of substituents about the central C-C bond is established. The five- and six-membered rings are oriented at a dihedral angle of 75.88 (8)°. In the crystal, N-H⋯N hydrogen bonds form chains of mol-ecules extending along the c -axis direction that are connected by inversion-related pairs of O-H⋯N into ribbons. The ribbons are linked by C-H⋯π(ring) inter-actions, forming layers parallel to the ab plane. A Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H⋯H (45.9%), H⋯N/N⋯H (23.3%), H⋯C/C⋯H (16.2%) and H⋯O/O⋯H (12.3%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. The volume of the crystal voids and the percentage of free space were calculated to be 100.94 Å 3 and 13.20%, showing that there is no large cavity in the crystal packing. Evaluation of the electrostatic, dispersion and total energy frameworks indicates that the stabilization is dominated by the electrostatic energy contributions in the title compound. Moreover, the DFT-optimized structure at the B3LYP/6-311 G(d,p) level is compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap., (© Ait Elmachkouri et al. 2024.)

The in-do-line portion of the title mol-ecule, C 16 H 13 NO 2 , is planar. In the crystal, a layer structure is generated by C-H⋯O hydrogen bonds and C-H⋯π(ring), π-stacking and C=O⋯π(ring) inter-actions. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (43.0%), H⋯C/C⋯H (25.0%) and H⋯O/O⋯H (22.8%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. The volume of the crystal voids and the percentage of free space were calculated to be 120.52 Å 3 and 9.64%, respectively, showing that there is no large cavity in the crystal packing. Evaluation of the electrostatic, dispersion and total energy frameworks indicate that the stabilization is dominated by the dispersion energy contributions in the title compound. Moreover, the DFT-optimized structure at the B3LYP/6-311G(d,p) level is compared with the experimentally determined mol-ecular structure in the solid state., (© Rharmili et al. 2024.)

A series of new pyrazolopyranopyrimidine derivatives ( 3-9 ) were synthesized from 5-amino-2,4-dihydro-3-methyl-4-phenylpyrano-[2,3-c]pyrazole-5-carbonitrile (2) by multicomponent reactions (MCR) involving malononitrile, benzaldehyde, and pyrazolone under refluxing ethanol in the presence of piperidine. Compound (2) was then converted to 2-acetylpyrazolopyranopyrimidine ( 3) through a reaction with acetic anhydride. The deprotection of 3 using ammonium hydroxide in ethanol, leads to 4 . Subsequent chlorination of 4 by phosphorus oxychloride affords 5 which was alkylated using methyl iodide and ethyl bromoacetate in DMF, leading to regioisomers 6 - 9 . The products were characterized by spectroscopic techniques ( 1 H and 13 C NMR) and confirmed by single crystal X-ray diffraction (XRD) studies for 2 , 5 , 6, and 9 . Moreover, the geometrical parameters, molecular orbital calculations, and spectral data of 2 , 5 , 6, and 9 were compared by DFT at the B3LYP/6-311G(d,p) level of theory. There is good agreement between the calculated results and the experimental data. The intermolecular contacts for 2 , 5 , 6, and 9 were studied by Hirshfeld surface analysis. In addition, the molecular docky study was conducted to investigate the binding patterns of 2 , 5 , 6, and 9 within the binding site of cyclin-dependent kinase 2 ( CDK2) and penicillin-binding protein 1 A. After the docking process, molecular dynamics (MD) simulations for 100 ns were performed on CDK2 and PBP 1 A proteins in the complex with 5 .Communicated by Ramaswamy H. Sarma.

In the title mol-ecule, C 7 H 7 N 3 O, the pyrimidine ring is essentially planar, with the propynyl group rotated out of this plane by 15.31 (4)°. In the crystal, a tri-periodic network is formed by N-H⋯O, N-H⋯N and C-H⋯O hydrogen-bonding and slipped π-π stacking inter-actions, leading to narrow channels extending parallel to the c axis. Hirshfeld surface analysis of the crystal structure reveals that the most important contributions for the crystal packing are from H⋯H (36.2%), H⋯C/C⋯H (20.9%), H⋯O/O⋯H (17.8%) and H⋯N/N⋯H (12.2%) inter-actions, showing that hydrogen-bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Evaluation of the electrostatic, dispersion and total energy frameworks indicates that the stabilization is dominated by the electrostatic energy contributions. The mol-ecular structure optimized by density functional theory (DFT) calculations at the B3LYP/6-311 G(d,p) level is compared with the experimentally determined structure in the solid state. The HOMO-LUMO behaviour was also elucidated to determine the energy gap., (© Lahyaoui et al. 2023.)

The title mol-ecule, C 29 H 44 N 8 O, adopts a conformation resembling a two-bladed fan with the octyl chains largely in fully extended conformations. In the crystal, C-H⋯O hydrogen bonds form chains of mol-ecules extending along the b -axis direction, which are linked by weak C-H⋯N hydrogen bonds and C-H⋯π inter-actions to generate a three-dimensional network. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (68.3%), H⋯N/N⋯H (15.7%) and H⋯C/C⋯H (10.4%) inter-actions., (© Zouhair et al. 2023.)

In the title compound, C 20 H 28 BrNO 2 , the indoline portion is almost planar and the 12-bromo-dodecyl chain adopts an all- trans conformation apart from the gauche terminal C-C-C-Br fragment. A micellar-like structure is generated in the crystal by C-H⋯O hydrogen bonds and π-stacking inter-actions between indolinedione head groups and inter-calation of the 12-bromo-dodecyl tails. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (58.9%), H⋯O/O⋯H (17.9%) and H⋯Br/Br⋯H (9.5%) contacts. A density functional theory (DFT) optimized structure at the B3LYP/ 6-311 G(d,p) level shows good agreement with the experimentally determined mol-ecular structure in the solid state., (© Rharmili et al. 2023.)

In the title mol-ecule, C 8 H 7 NO 3 S, the nitro-gen atom has a planar environment, and the thia-zine ring exhibits a screw-boat conformation. In the crystal, corrugated layers of mol-ecules parallel to the ab plane are formed by N-H⋯O and C-H⋯O hydrogen bonds together with C-H⋯π(ring) and S=O⋯π(ring) inter-actions. The layers are connected by additional C-H⋯O hydrogen bonds and π-stacking inter-actions. Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H⋯O/O⋯H (49.4%), H⋯H (23.0%) and H⋯C/C⋯H (14.1%) inter-actions. The volume of the crystal voids and the percentage of free space were calculated as 75.4 Å 3 and 9.3%. Density functional theory (DFT) computations revealed N-H⋯O and C-H⋯O hydrogen-bonding energies of 43.3, 34.7 and 34.4 kJ mol -1 , respectively. Evaluation of the electrostatic, dispersion and total energy frameworks indicate that the stabilization is dominated via the electrostatic energy contribution. Moreover, the DFT-optimized structure at the B3LYP/ 6-311 G(d,p) level is compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap., (© Irrou et al. 2023.)

The asymmetric unit of the title compound, C 12 H 13 N 3 O 4 , consists of two mol-ecules differing to a small degree in their conformations. In the crystal, layers of mol-ecules are connected by weak C-H⋯O hydrogen bonds and slipped π-stacking inter-actions. These layers lie parallel to (10) and are stacked along the normal to that plane. Hirshfeld surface analysis indicates that the most important contributions for the crystal packing arise from H⋯H (43.5%) and H⋯O/O⋯H (30.8%) contacts. The density functional theory (DFT) optimized structure of the title compound at the B3LYP/ 6-311 G(d,p) level agrees well with the experimentally determined mol-ecular structure in the solid state., (© Yousra et al. 2023.)

In the title mol-ecule, C 14 H 11 NO 3 , the di-hydro-quinoline core deviates slightly from planarity, indicated by the dihedral angle of 1.07 (3)° between the two six-membered rings. In the crystal, layers of mol-ecules almost parallel to the bc plane are formed by C-H⋯O hydro-gen bonds. These are joined by π-π stacking inter-actions. A Hirshfeld surface analysis revealed that the most important contributions to the crystal packing are from H⋯H (36.0%), H⋯C/C⋯H (28.9%) and H⋯O/O⋯H (23.5%) inter-actions. The evaluation of the electrostatic, dispersion and total energy frameworks indicates that the stabilization is dominated by the dispersion energy contribution. Moreover, the mol-ecular structure optimized by density functional theory (DFT) at the B3LYP/6-311G(d,p) level is com-pared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap., (© El-Mrabet et al. 2023.)

The asymmetric unit of the title mol-ecule, C 8 H 7 NO 3 , consists of two mol-ecules differing slightly in conformation and in their inter-molecular inter-actions in the solid. The dihedral angle between the benzene and dioxolane rings is 0.20 (7)° in one mol-ecule and 0.31 (7)° in the other. In the crystal, the two mol-ecules are linked into dimers through pairwise O-H⋯N hydrogen bonds, with these units being formed into stacks by two different sets of aromatic π-stacking inter-actions. The stacks are connected by C-H⋯O hydrogen bonds. A Hirshfeld surface analysis indicates that the most significant contacts in the crystal packing are H⋯O/O⋯H (36.7%), H⋯H (32.2%) and C⋯H/H⋯C (12.7%)., (© Radhakrishnan et al. 2023.)

Novel 6-bromo-imidazo[4,5-b]pyridine derivatives ( 2 - 4 , 5a -1 3a , and 6b , 8b - 13b ) have been synthesized based on a developed systematic approach involving the condensation of 5-Bromo-2,3-diaminopyridine with a suitable aromatic aldehyde in the presence of molecular iodine in water, followed by alkylation reactions using different alkyl dibromide agents. The synthesized compounds were characterized by the NMR spectroscopy technique. The structures of 8a , 9a , 12a, and 11b were confirmed using monocrystalline X-ray crystallography. Theoretical calculations have been carried out using DFT and TD-DFT methods at the B3LYP/6-31G++(d,p) level of theory. Intermolecular contacts between units of 8a , 9a , 12a , and 11b were determined through the Hirshfeld surface analysis. The molecular docking study has been performed to determine the binding affinity of 8a , 9a , 12a, and 11b into the binding site of S. aureus tyrosyl-tRNA synthetase as a target enzyme, and the results revealed that 9a is the most potent compound among the selected compounds with a binding affinity of -8.74 Kcal/mol.Communicated by Ramaswamy H. Sarma.

In the title mol-ecule, C 7 H 6 N 4 O 3 , the bicyclic ring system is planar with the carb-oxy-methyl group inclined by 81.05 (5)° to this plane. In the crystal, corrugated layers parallel to (010) are generated by N-H⋯O, O-H⋯N and C-H⋯O hydrogen-bonding inter-actions. The layers are associated through C-H⋯π(ring) inter-actions. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯O/O⋯H (34.8%), H⋯N/N⋯H (19.3%) and H⋯H (18.1%) inter-actions. The volume of the crystal voids and the percentage of free space were calculated to be 176.30 Å 3 and 10.94%, showing that there is no large cavity in the crystal packing. Computational methods revealed O-H⋯N, N-H⋯O and C-H⋯O hydrogen-bonding energies of 76.3, 55.2, 32.8 and 19.1 kJ mol -1 , respectively. Evaluations of the electrostatic, dispersion and total energy frameworks indicate that the stabilization is dominated via dispersion energy contributions. Moreover, the optimized mol-ecular structure, using density functional theory (DFT) at the B3LYP/6-311G(d,p) level, was compared with the experimentally determined one. The HOMO-LUMO energy gap was determined and the mol-ecular electrostatic potential (MEP) surface was calculated at the B3LYP/6-31G level to predict sites for electrophilic and nucleophilic attacks., (© Irrou et al. 2022.)

The asymmetric unit of the title compound, C 14 H 13 NO 4 , contains three independent mol-ecules, which differ slightly in conformation. Each contains an intra-molecular N-H⋯O hydrogen bond. In the crystal, O-H⋯O hydrogen bonds form chains of mol-ecules, which are linked into corrugated sheets parallel to (03) plane by C-H⋯O hydrogen bonds together with π inter-actions between the carbonyl groups and the 2-hy-droxy-phenyl rings. The layers are linked by further C-H⋯O hydrogen bonds. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (49.0%), H⋯O/O⋯H (28.3%) and H⋯C/C⋯H (10.9%) inter-actions. van der Waals inter-actions are the dominant inter-actions in the crystal packing. Moreover, density functional theory (DFT) optimized structures at the B3LYP/ 6-311 G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behavior was elucidated to determine the energy gap of 4.53 eV., (© Faraj et al. 2022.)

In the title compound, C 12 H 10 ClNO 3 , the di-hydro-quinoline moiety is not planar with a dihedral angle between the two ring planes of 1.61 (6)°. An intra-molecular C-H⋯O hydrogen bond helps to establish the rotational orientation of the carboxyl group. In the crystal, sheets of mol-ecules parallel to (10) are generated by C-H⋯O and C-H⋯Cl hydrogen bonds, and are stacked through slipped π-stacking inter-actions between inversion-related di-hydro-quinoline units. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (34.2%), H⋯O/O⋯H (19.9%), H⋯Cl/Cl⋯H (12.8%), H⋯C/C⋯H (10.3%) and C⋯C (9.7%) inter-actions. Computational chemistry indicates that in the crystal, the C-H⋯Cl hydrogen-bond energy is -37.4 kJ mol -1 , while the C-H⋯O hydrogen-bond energies are -45.4 and -29.2 kJ mol -1 . An evaluation of the electrostatic, dispersion and total energy frameworks revealed that the stabilization is dominated via the dispersion energy contribution. Density functional theory (DFT) optimized structures at the B3LYP/6-311 G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state, and the HOMO-LUMO behaviour was elucidated to determine the energy gap., (© Filali Baba et al. 2022.)

The substituted cyclo-penta-dienyl ring in the title mol-ecule, [Fe(C 5 H 5 )(C 18 H 13 ClN)], is nearly coplanar with the phenyl-1-(4-chloro-phen-yl)methanimine substituent, with dihedral angles between the planes of the phenyl-ene ring and the Cp and 4-(chloro-phen-yl)methanimine units of 7.87 (19) and 9.23 (10)°, respectively. The unsubstituted cyclo-penta-dienyl ring is rotationally disordered, the occupancy ratio for the two orientations refined to a 0.666 (7)/0.334 (7) ratio. In the crystal, the mol-ecules pack in 'bilayers' parallel to the ab plane with the ferrocenyl groups on the outer faces and the substituents directed towards the regions between them. The ferrocenyl groups are linked by C-H⋯π(ring) inter-actions. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (46.1%), H⋯C/C⋯ H (35.4%) and H⋯Cl/Cl⋯H (13.8%) inter-actions. Thus C-H⋯π(ring) and van der Waals inter-actions are the dominant inter-actions in the crystal packing., (© Sghyar et al. 2021.)

The title compound {systematic name: ( S , E )-3-[4-(furan-2-yl)-2,3,4,5-tetra-hydro-1 H -benzo[ b ][1,4]diazepin-2-yl-idene]-6-methyl-2 H -pyran-2,4(3 H )-dione}, C 19 H 16 N 2 O 4 , is constructed from a benzodiazepine ring system linked to furan and pendant di-hydro-pyran rings, where the benzene and furan rings are oriented at a dihedral angle of 48.7 (2)°. The pyran ring is modestly non-planar [largest deviation of 0.029 (4) Å from the least-squares plane] while the tetra-hydro-diazepine ring adopts a boat conformation. The rotational orientation of the pendant di-hydro-pyran ring is partially determined by an intra-molecular N-H Diazp ⋯O Dhydp (Diazp = diazepine and Dhydp = di-hydro-pyran) hydrogen bond. In the crystal, layers of mol-ecules parallel to the bc plane are formed by N-H Diazp ⋯O Dhydp hydrogen bonds and slipped π-π stacking inter-actions. The layers are connected by additional slipped π-π stacking inter-actions. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (46.8%), H⋯O/O⋯H (23.5%) and H⋯C/C⋯H (15.8%) inter-actions, indicating that van der Waals inter-actions are the dominant forces in the crystal packing. Computational chemistry indicates that in the crystal the N-H⋯O hydrogen-bond energy is 57.5 kJ mol -1 ., (© El Hafi et al. 2021.)

The title mol-ecule, C 17 H 26 N 2 O, adopts an L-shaped conformation, with the straight n -decyl chain positioned nearly perpendicular to the di-hydro-benzimidazole moiety. The di-hydro-benzimidazole portion is not quite planar as there is a dihedral angle of 1.20 (6)° between the constituent planes. In the crystal, N-H⋯O hydrogen bonds form inversion dimers, which are connected into the three-dimensional structure by C-H⋯O hydrogen bonds and C-H⋯π(ring) inter-actions. Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H⋯H (75.9%), H⋯C/C⋯H (12.5%) and H⋯O/O⋯H (7.0%) inter-actions. Based on computational chemistry using the CE-B3LYP/6-31 G(d,p) energy model, C-H⋯O hydrogen bond energies are -74.9 (for N-H⋯O) and -42.7 (for C-H⋯O) kJ mol -1 ., (© Ait Elmachkouri et al. 2021.)

In the title mol-ecule, C 20 H 24 Br 2 N 4 , the imidazo-pyridine moiety is not planar as indicated by the dihedral angle of 2.0 (2)° between the constituent rings; the 4-di-methyl-amino-phenyl ring is inclined to the mean plane of the imidazole ring by 27.4 (1)°. In the crystal, two sets of C-H⋯π(ring) inter-actions form stacks of mol-ecules extending parallel to the a- axis direction. Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯H (42.2%), H⋯C/C⋯H (23.1%) and H⋯Br/Br⋯H (22.3%) inter-actions. The optimized structure calculated using density functional theory (DFT) at the B3LYP/ 6-311 G(d,p) level is compared with the experimentally determined structure in the solid state. The calculated HOMO-LUMO energy gap is 2.3591 eV., (© Jabri et al. 2020.)

In the title mol-ecule, C 20 H 21 N 3 O 3 , the allyl substituent is rotated out of the plane of its attached phenyl ring [torsion angle 100.66 (15)°]. In the crystal, C-H Mthphn ⋯O Mthphn (Mthphn = meth-oxy-phen-yl) hydrogen bonds lead to the formation of (100) layers that are connected into a three-dimensional network by C-H⋯π(ring) inter-actions, together with π-π stacking inter-actions [centroid-to-centroid distance = 3.7318 (10) Å] between parallel phenyl rings. Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯H (48.7%) and H⋯C/C⋯H (23.3%) inter-actions. Computational chemistry reveals that the C-H Mthphn ⋯O Mthphn hydrogen bond energy is 47.1 kJ mol -1 . The theoretical structure, optimized by density functional theory (DFT) at the B3LYP/ 6-311 G(d,p) level, is compared with the experimentally determined mol-ecular structure. The HOMO-LUMO behaviour was elucidated to determine the energy gap., (© Taia et al. 2020.)

The title compound, C 22 H 25 NOS, consists of methyl-benzyl-idene and benzo-thia-zine units linked to a hexyl moiety, where the thia-zine ring adopts a screw-boat conformation. In the crystal, inversion dimers are formed by weak C-H Mthn ⋯O Bnzthz hydrogen bonds and are linked into chains extending along the a -axis direction by weak C-H Bnz ⋯O Bnzthz (Bnz = benzene, Bnzthz = benzo-thia-zine and Mthn = methine) hydrogen bonds. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (59.2%) and H⋯C/C⋯H (27.9%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Computational chemistry indicates that in the crystal, the C-H Bnz ⋯O Bnzthz and C-H Mthn ⋯O Bnzthz hydrogen-bond energies are 75.3 and 56.5 kJ mol -1 , respectively. Density functional theory (DFT) optimized structures at the B3LYP/ 6-311 G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap. Moreover, the anti-bacterial activity of the title compound was evaluated against gram-positive and gram-negative bacteria., (© Sebbar et al. 2020.)

The title compound, C 19 H 16 ClNO 3 S, consists of chloro-phenyl methyl-idene and di-hydro-benzo-thia-zine units linked to an acetate moiety, where the thia-zine ring adopts a screw-boat conformation. In the crystal, two sets of weak C-H Ph ⋯O Dbt (Ph = phenyl and Dbt = di-hydro-benzo-thia-zine) hydrogen bonds form layers of mol-ecules parallel to the bc plane. The layers stack along the a -axis direction with inter-calation of the ester chains. The crystal studied was a two component twin with a refined BASF of 0.34961 (5). The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions to the crystal packing are from H⋯H (37.5%), H⋯C/C⋯H (24.6%) and H⋯O/O⋯H (16.7%) inter-actions. Hydrogen-bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Computational chemistry indicates that in the crystal, C-H Ph ⋯O Dbt hydrogen bond energies are 38.3 and 30.3 kJ mol -1 . Density functional theory (DFT) optimized structures at the B3LYP/ 6-311 G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap. Moreover, the anti-bacterial activity of the title compound has been evaluated against gram-positive and gram-negative bacteria., (© Sebbar et al. 2020.)

In the title mol-ecule, C 12 H 13 N 3 O 2 S, the benzo-thia-zine moiety is slightly non-planar, with the imidazolidine portion twisted only a few degrees out of the mean plane of the former. In the crystal, a layer structure parallel to the bc plane is formed by a combination of O-H Hydethy ⋯N Thz hydrogen bonds and weak C-H Imdz ⋯O Imdz and C-H Bnz ⋯O Imdz (Hydethy = hy-droxy-ethyl, Thz = thia-zole, Imdz = imidazolidine and Bnz = benzene) inter-actions, together with C-H Imdz ⋯π(ring) and head-to-tail slipped π-stacking [centroid-to-centroid distances = 3.6507 (7) and 3.6866 (7) Å] inter-actions between thia-zole rings. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (47.0%), H⋯O/O⋯H (16.9%), H⋯C/C⋯H (8.0%) and H⋯S/S⋯H (7.6%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Computational chemistry indicates that in the crystal, C-H⋯N and C-H⋯O hydrogen-bond energies are 68.5 (for O-H Hydethy ⋯N Thz ), 60.1 (for C-H Bnz ⋯O Imdz ) and 41.8 kJ mol -1 (for C-H Imdz ⋯O Imdz ). Density functional theory (DFT) optimized structures at the B3LYP/6-311 G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state., (© Srhir et al. 2020.)

The title compound, C 24 H 27 Cl 2 NOS, contains 1,4-benzo-thia-zine and 2,4-di-chloro-phenyl-methyl-idene units in which the di-hydro-thia-zine ring adopts a screw-boat conformation. In the crystal, inter-molecular C-H Bnz ⋯O Thz (Bnz = benzene and Thz = thia-zine) hydrogen bonds form chains of mol-ecules extending along the a -axis direction, which are connected to their inversion-related counterparts by C-H Bnz ⋯Cl Dchlphy (Dchlphy = 2,4-di-chloro-phen-yl) hydrogen bonds and C-H Dchlphy ⋯π (ring) inter-actions. These double chains are further linked by C-H Dchlphy ⋯O Thz hydrogen bonds, forming stepped layers approximately parallel to (012). The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (44.7%), C⋯H/H⋯C (23.7%), Cl⋯H/H⋯Cl (18.9%), O⋯H/H⋯O (5.0%) and S⋯H/H⋯S (4.8%) inter-actions. Hydrogen-bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Computational chemistry indicates that in the crystal, C-H Dchlphy ⋯O Thz , C-H Bnz ⋯O Thz and C-H Bnz ⋯Cl Dchlphy hydrogen-bond energies are 134.3, 71.2 and 34.4 kJ mol -1 , respectively. Density functional theory (DFT) optimized structures at the B3LYP/6-311 G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap. The two carbon atoms at the end of the nonyl chain are disordered in a 0.562 (4)/0.438 (4) ratio., (© Hni et al. 2020.)

In the title mol-ecule, C 24 H 21 N 5 O·H 2 O, the di-hydro-benzo-diazole moiety is not quite planar, while the whole mol-ecule adopts a U-shaped conformation in which there is a close approach of the two benzyl groups. In the crystal, chains of alternating mol-ecules and lattice water extending along [201] are formed by O-H UncoordW ⋯O Dhyr and O-H UncoordW ⋯N Trz (UncoordW = uncoordinated water, Dhyr = di-hydro and Trz = triazole) hydrogen bonds. The chains are connected into layers parallel to (010) by C-H Trz ⋯O UncoordW hydrogen bonds with the di-hydro-benzo-diazole units in adjacent layers inter-calating to form head-to-tail π-stacking [centroid-to-centroid distance = 3.5694 (11) Å] inter-actions between them, which generates the overall three-dimensional structure. Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H⋯H (52.1%), H⋯C/C⋯H (23.8%) and O⋯H/H⋯O (11.2%) inter-actions. Hydrogen-bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Density functional theory (DFT) optimized structures at the B3LYP/ 6-311 G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap., (© Saber et al. 2020.)

In the title mol-ecule, C 11 H 10 N 2 O, the di-hydro-benzimidazol-2-one moiety is essentially planar, with the prop-2-yn-1-yl substituent rotated well out of this plane. In the crystal, C-H Mthy ⋯π(ring) inter-actions and C-H Prop ⋯O Dhyr (Mthy = methyl, Prop = prop-2-yn-1-yl and Dhyr = di-hydro) hydrogen bonds form corrugated layers parallel to (10), which are associated through additional C-H Bnz ⋯O Dhyr (Bnz = benzene) hydrogen bonds and head-to-tail, slipped, π-stacking [centroid-to-centroid distance = 3.7712 (7) Å] inter-actions between di-hydro-benzimidazol-2-one moieties. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions to the crystal packing are from H⋯H (44.1%), H⋯C/C⋯H (33.5%) and O⋯H/H⋯O (13.4%) inter-actions. Hydrogen-bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Computational chemistry calculations indicate that in the crystal, C-H⋯O hydrogen-bond energies are 46.8 and 32.5 (for C-H Prop ⋯O Dhyr ) and 20.2 (for C-H Bnz ⋯O Dhyr ) kJ mol -1 . Density functional theory (DFT) optimized structures at the B3LYP/6-311 G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap., (© Saber et al. 2019.)

The title com-pound, C 24 H 24 N 2 O 6 , consists of ethyl 2-(1,2,3,4-tetra-hydro-2-oxo-quinolin-1-yl)acetate and 4-[(2-eth-oxy-2-oxoeth-yl)(phen-yl)carbomoyl] units, where the oxo-quinoline unit is almost planar and the acetate substituent is nearly perpendicular to its mean plane. In the crystal, C-H Oxqn ⋯O Ethx and C-H Ph-yl ⋯O Carbx (Oxqn = oxoquinolin, Ethx = eth-oxy, Phyl = phenyl and Carbx = carboxyl-ate) weak hydrogen bonds link the mol-ecules into a three-dimensional network sturucture. A π-π inter-action between the constituent rings of the oxo-quinoline unit, with a centroid-centroid distance of 3.675 (1) Å may further stabilize the structure. Both terminal ethyl groups are disordered over two sets of sites. The ratios of the refined occupanies are 0.821 (8):0.179 (8) and 0.651 (18):0.349 (18). The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (53.9%), H⋯O/O⋯H (28.5%) and H⋯C/C⋯H (11.8%) inter-actions. Weak inter-molecular hydrogen-bond inter-actions and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Density functional theory (DFT) geometric optimized structures at the B3LYP/6-311G(d,p) level are com-pared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO mol-ecular orbital behaviour was elucidated to determine the energy gap., (© Filali Baba et al. 2019.)

The title compound, C 22 H 15 Cl 2 NOS, contains 1,4-benzo-thia-zine and 2,4-di--chloro-benzyl-idene units, where the di-hydro-thia-zine ring adopts a screw-boat conformation. In the crystal, inter-molecular C-H Bnz ⋯O Thz (Bnz = benzene and Thz = thia-zine) hydrogen bonds form corrugated chains extending along the b -axis direction which are connected into layers parallel to the bc plane by inter-molecular C-H Methy ⋯S Thz (Methy = methyl-ene) hydrogen bonds, en-closing R 4 4 (22) ring motifs. Offset π-stacking inter-actions between 2,4-di--chloro-phenyl rings [centroid-centroid = 3.7701 (8) Å] and π-inter-actions which are associated by C-H Bnz ⋯π(ring) and C-H Dchlphy ⋯π(ring) (Dchlphy = 2,4-di-chloro-phen-yl) inter-actions may be effective in the stabilization of the crystal structure. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (29.1%), H⋯C/C⋯H (27.5%), H⋯Cl/Cl⋯H (20.6%) and O⋯H/H⋯O (7.0%) inter-actions. Hydrogen-bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Computational chemistry indicates that in the crystal, the C-H Bnz ⋯O Thz and C-H Methy ⋯S Thz hydrogen-bond energies are 55.0 and 27.1 kJ mol -1 , respectively. Density functional theory (DFT) optimized structures at the B3LYP/6-311G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap., (© Sebbar et al. 2019.)

The title com-pound, C 22 H 16 N 4 O 2 , contains two pyridine rings and one meth-oxy-carbonyl-phenyl group attached to a pyridazine ring which deviates very slightly from planarity. In the crystal, ribbons consisting of inversion-related chains of mol-ecules extending along the a -axis direction are formed by C-H Mthy ⋯O Carbx (Mthy = methyl and Carbx = carboxyl-ate) hydrogen bonds. The ribbons are connected into layers parallel to the bc plane by C-H Bnz ⋯π(ring) (Bnz = benzene) inter-actions. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (39.7%), H⋯C/C⋯H (27.5%), H⋯N/N⋯H (15.5%) and O⋯H/H⋯O (11.1%) inter-actions. Hydrogen-bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Computational chemistry indicates that in the crystal, C-H Mthy ⋯O Carbx hydrogen-bond energies are 62.0 and 34.3 kJ mol -1 , respectively. Density functional theory (DFT) optimized structures at the B3LYP/6-311G(d,p) level are com-pared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap., (© Filali et al. 2019.)

The title compound, C 15 H 12 ClNO 3 , consists of a 1,2-di-hydro-quinoline-4-carb-oxyl-ate unit with 2-chloro-ethyl and propynyl substituents, where the quinoline moiety is almost planar and the propynyl substituent is nearly perpendicular to its mean plane. In the crystal, the mol-ecules form zigzag stacks along the a -axis direction through slightly offset π-stacking inter-actions between inversion-related quinoline moieties which are tied together by inter-molecular C-H Prpn-yl ⋯O Carbx and C-H Chlethy ⋯O Carbx (Prpnyl = propynyl, Carbx = carboxyl-ate and Chlethy = chloro-eth-yl) hydrogen bonds. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (29.9%), H⋯O/O⋯H (21.4%), H⋯C/C⋯ H (19.4%), H⋯Cl/Cl⋯H (16.3%) and C⋯C (8.6%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Computational chemistry indicates that in the crystal, the C-H Prpn-yl ⋯O Carbx and C-H Chlethy ⋯O Carbx hydrogen bond energies are 67.1 and 61.7 kJ mol -1 , respectively. Density functional theory (DFT) optimized structures at the B3LYP/ 6-311 G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap., (© Hayani et al. 2019.)

The title compound, C 18 H 16 N 4 O, consists of a 3,6-bis-(pyridin-2-yl)pyridazine moiety linked to a 4-[(prop-2-en-1-yl-oxy)meth-yl] group. The pyridine-2-yl rings are oriented at a dihedral angle of 17.34 (4)° and are rotated slightly out of the plane of the pyridazine ring. In the crystal, C-H Pyrd ⋯N Pyrdz (Pyrd = pyridine and Pyrdz = pyridazine) hydrogen bonds and C-H Prp-oxy ⋯π (Prp-oxy = prop-2-en-1-yl-oxy) inter-actions link the mol-ecules, forming deeply corrugated layers approximately parallel to the bc plane and stacked along the a -axis direction. Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H⋯H (48.5%), H⋯C/C⋯H (26.0%) and H⋯N/N⋯H (17.1%) contacts, hydrogen bonding and van der Waals inter-actions being the dominant inter-actions in the crystal packing. Computational chemistry indicates that in the crystal, the C-H Pyrd ⋯N Pyrdz hydrogen-bond energy is 64.3 kJ mol -1 . Density functional theory (DFT) optimized structures at the B3LYP/6-311 G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.

The title compound, C 18 H 12 Cl 2 N 2 OS, consists of a di-hydro-benzo-thia-zine unit linked by a -CH group to a 2,4-di-chloro-phenyl substituent, and to a propane-nitrile unit is folded along the S⋯N axis and adopts a flattened-boat conformation. The propane-nitrile moiety is nearly perpendicular to the mean plane of the di-hydro-benzo-thia-zine unit. In the crystal, C-H Bnz ⋯N Prpnit and C-H Prpnit ⋯O Thz (Bnz = benzene, Prpnit = propane-nitrile and Thz = thia-zine) hydrogen bonds link the mol-ecules into inversion dimers, enclosing R 2 2 (16) and R 2 2 (12) ring motifs, which are linked into stepped ribbons extending along [110]. The ribbons are linked in pairs by complementary C=O⋯Cl inter-actions. π-π contacts between the benzene and phenyl rings, [centroid-centroid distance = 3.974 (1) Å] may further stabilize the structure. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (23.4%), H⋯Cl/Cl⋯H (19.5%), H⋯C/C⋯H (13.5%), H⋯N/N⋯H (13.3%), C⋯C (10.4%) and H⋯O/O⋯H (5.1%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Computational chemistry calculations indicate that the two independent C-H Bnz ⋯N Prpnit and C-H Prpnit ⋯O Thz hydrogen bonds in the crystal impart about the same energy ( ca 43 kJ mol -1 ). Density functional theory (DFT) optimized structures at the B3LYP/6-311 G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.

The title compound, C 20 H 16 Cl 2 N 2 O 3 S, is built up from a di-hydro-benzo-thia-zine moiety linked by -CH- and -C 2 H 4 - units to 2,4-di-chloro-phenyl and 2-oxo-1,3-oxazolidine substituents, where the oxazole ring and the heterocyclic portion of the di-hydro-benzo-thia-zine unit adopt envelope and flattened-boat conformations, respectively. The 2-carbon link to the oxazole ring is nearly perpendicular to the mean plane of the di-hydro-benzo-thia-zine unit. In the crystal, the mol-ecules form stacks extending along the normal to (104) with the aromatic rings from neighbouring stacks inter-calating to form an overall layer structure. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (28.4%), H⋯Cl/Cl⋯H (19.3%), H⋯O/O⋯H (17.0%), H⋯C/C⋯H (14.5%) and C⋯C (8.2%) inter-actions. Weak hydrogen-bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Density functional theory (DFT) optimized structures at the B3LYP/ 6-311 G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.

The title compound, C 18 H 12 FNOS, is built up from a 4-fluoro-benzyl-idene moiety and a di-hydro-benzo-thia-zine unit with a propynyl substituent, with the heterocyclic portion of the di-hydro-benzo-thia-zine unit adopting a shallow boat conformation with the propynyl substituent nearly perpendicular to it. The two benzene rings are oriented at a dihedral angle of 43.02 (6)°. In the crystal, C-H Flurphen ⋯F Flurphen (Flurphen = fluoro-phen-yl) hydrogen bonds link the mol-ecules into inversion dimers, enclosing R 2 2 (8) ring motifs, with the dimers forming oblique stacks along the a -axis direction. Hirshfeld surface analysis of the crystal structure indicates that the most important contributions to the crystal packing are from H⋯H (33.9%), H⋯C/C⋯H (26.7%), H⋯F/F⋯H (10.9%) and C⋯C (10.6%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Density functional theory (DFT) optimized structures at the B3LYP/6-311 G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.

In the present study, two pyrazole-acetamide derivatives namely N‑(2‑aminophenyl)‑2‑(5‑methyl‑1H‑pyrazol‑3‑yl) acetamide (L1) and (E)‑N‑(2‑(1‑(2‑hydroxy‑6‑methyl‑4‑oxo‑4H‑pyran‑3‑yl)ethylideneamino)phenyl)‑2‑(5‑methyl‑1H‑pyrazol‑3‑yl) acetamide (L2) have been synthesized and characterized by infrared spectrophotometry (IR), nuclear magnetic resonance spectroscopy (NMR) and electrospray ionization-mass spectrometry (ESI-MS). Two coordination complexes of L1 and L2, namely [Co(L1) 2 (EtOH) 2 ]·Cl 2 (1) and [Cu(L2)]·H 2 O (2), respectively have been synthesized and characterized by elemental analysis and spectroscopic studies. The solid state structure of these two complexes was established by single crystal X-ray crystallography. In complex 1, the amide O and pyrazole N atoms of two molecules of L1 take part in coordination with octahedral Co(II) ions, the remaining two coordination sites being occupied by two EtOH molecules leading to a N 2 O 4 coordination environment. On the other hand, the imine N atoms, pyrazole N and O atoms of the 2‑hydroxy‑6‑methyl‑4H‑pyran‑4‑one function present in L2 are involved in coordination with Cu(II) ions, resulting in a distorted square planar geometry displaying a N 2 O 4 chromophore, in complex 2. The crystal packing analysis of 1 and 2, revealed 1D and 2D supramolecular architectures respectively, via various hydrogen bonding interactions, which are discussed in the present account. Furthermore, the antioxidant activity of the ligands and their complexes were determined in vitro by 1,1‑diphenyl‑2‑picrylhydrazyl (DPPH), 2,2'‑azino‑bis(3‑ethylbenzothiazoline‑6‑sulphonic acid (ABTS) and ferric reducing antioxidant power(FRAP), showing that the ligands L1 and L2 and complexes 1 and 2 present significant antioxidant activity., (Copyright © 2018 Elsevier Inc. All rights reserved.)

The title compound, C 17 H 18 N 2 O 3 , is constructed from a benzodiazepine ring system linked to a pendant di-hydro-pyran ring, where the benzene and pendant di-hydro-pyran rings are oriented at a dihedral angle of 15.14 (4)°. Intra-molecular N-H Diazp ⋯O Dhydp and C-H Diazp ⋯O Dhydp (Diazp = diazepine and Dhydp = di-hydro-pyran) hydrogen bonds link the seven-membered diazepine ring to the pendant di-hydro-pyran ring, enclosing S (6) ring motifs. In the crystal, N-H Diazp ⋯O Dhydp hydrogen bonds link the mol-ecules into infinite chains along [10]. These chains are further linked via C-H Bnz ⋯O Dhydp , C-H Dhydp ⋯O Dhydp and C-H Mth ⋯O Dhydp (Bnz = benzene and Mth = meth-yl) hydrogen bonds, forming a three-dimensional network. The observed weak C-H Diazp ⋯ π inter-action may further stabilize the structure. Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (51.1%), H⋯C/C⋯H (25.3%) and H⋯O/O⋯H (20.3%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing.

Background: A novel series of 1,2,3-triazole derivatives containing 1,4-benzothiazin-3-one ring (7a-9a, 7b-9b), (10a-12a, 10b-12b) and (13-15) were synthesized by 1,3-dipolar cycloaddition reactions of azides α-D-galactopyranoside azide F, 2,3,4,6-tetra-O-acetyl-(D)-glucopyranosyl azide G and methyl-N-benzoyl-α-azidoglycinate H with compounds 4-6., Findings: Initially, the reactions were conducted under thermal conditions in ethanol. The reaction leads, each time, to the formation of two regioisomers: (Schemes 2, 3) with yields of 17 to 21% for 1,5-disubstituted 1,2,3-triazole-regioisomers (7b-12b) and yields ranging from 61 to 65% for the 1,4-disubstituted regioisomers (7a-12a). In order to report an unequivocal synthesis of the 1,4-regioisomers and confirm the structures of the two regioisomers obtained in thermal conditions (Huisgen reactions), the method click chemistry (Copper-Catalyzed Azide-Alkyne Cycloaddition) has been used., Conclusions: The newly synthesized compounds using cycloaddition reactions were evaluated in vitro for their antibacterial activities against some Gram positive and Gram negative microbial strains. Among the compounds tested, the compound 8a showed excellent antibacterial activities against PA ATCC and Acin ESBL (MIC = 31.2 μg/ml).

The title compound, C 17 H 14 N 2 O, is built up from the planar benzo-diazole unit linked to the benzyl and propynyl substituents. The substituents are rotated significantly out of the benzo-diazole plane, where the benzyl group is inclined by 68.91 (7)° to the benzo-diazole unit. In the crystal, the mol-ecules are linked via inter-molecular C-H Bnzdzl ⋯O and C-H Bnzy ⋯O (Bnzdzl = benzo-diazole and Bnzy = benz-yl) hydrogen bonds, enclosing R 4 4 (27) ring motifs, into a network consisting of rectangular layers parallel to the bc plane which are also stacked along the a -axis direction being associated through C-H⋯π (ring) inter-actions. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (43.6%), H⋯C/C⋯H (42.0%) and H⋯O/O⋯H (8.9%) inter-actions.

The nine-membered ring system of the title compound, C 6 H 6 N 4 , is essentially planar. In the crystal, mol-ecules are linked via C-H Trz ⋯N Trz and C-H Pyrm ⋯N Trz (Trz = triazole and Pyrm = pyrimidine) hydrogen bonds together with weaker C-H Pyrm ⋯N Pyrm hydrogen bonds to form layers parallel to (02). The layers are further connected by π-π-stacking inter-actions between the nine-membered ring system [centroid-centroid = 3.7910 (8) Å], forming oblique stacks along the a -axis direction. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯N/N⋯H (40.1%), H⋯H (35.3%), H⋯C/C⋯H (9.5%), N⋯C/C⋯N (9.0%), N⋯N (3.1%) and C⋯C (3.0%) inter-actions and that hydrogen-bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. No significant C-H⋯π inter-actions are observed.

The title compound, C 16 H 19 N 5 O, is built up from a planar quinoxalinone ring system linked through a methyl-ene bridge to a 1,2,3-triazole ring, which in turn carries an n -butyl substituent. The triazole ring is inclined by 67.09 (4)° to the quinoxalinone ring plane. In the crystal, the mol-ecules form oblique stacks along the a -axis direction through inter-molecular C-H Trz ⋯N Trz (Trz = triazole) hydrogen bonds, and offset π-stacking inter-actions between quinoxalinone rings [centroid-centroid distance = 3.9107 (9) Å] and π-π inter-actions, which are associated pairwise by inversion-related C-H Dhydqn ⋯π(ring) (Dhydqn = di-hydro-quinoxaline) inter-actions. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (52.7%), H⋯N/N⋯H (18.9%) and H⋯C/C⋯H (17.0%) inter-actions.