Zinc(II) coordination compound with N'-(pyridin-2-ylmethylene)nicotinohydrazide: Synthesis, crystal structure, computational and cytotoxicity studies.

In this work, we report on the synthesis of a novel zinc(II) coordination compound [ZnL2] (1), which was readily obtained from the reaction of Zn(OAc)·2H2O and N'-(pyridin-2-ylmethylene)nicotinohydrazide (HL) in methanol. Recrystallization of 1 from dimethylformamide under ambient conditions allowed to produce yellow block-like crystals of 1·H2O. Complex 1·H2O was characterized by FT-IR and 1H NMR spectroscopy, while its optical properties were studied by UV-vis and spectrofluorimetry in methanol. The crystal structure of the title complex was revealed by single crystal X-ray diffraction and further explored in detail by the Hirshfeld surface analysis. Theoretical investigations based on the DFT calculations have also been applied to show the electronic properties of complex 1. The antitumor activities of the parent ligand HL and complex 1 were studied using Dalton's lymphoma malignant cancer model. Both compounds were found to induce concentration-dependent cytotoxicity and apoptotic cell death, leading to a decrease in cell viability, body weight, and tumor volume in mice with the superior activity of complex 1 over HL. Mice treated with complex 1 demonstrated an increase in life span with a survival period of 23 days. Finally, using a molecular docking approach, we have probed complex 1 to inhibit the recombinant mouse tumor-necrosis factor alpha (mTNF).

Synthesis, Spectroscopic Characterization, Single-Crystal Structure, Hirshfeld Surface Analysis, and Antimicrobial Studies of 3-Acetoxy-2-methylbenzoic Anhydride.

We report a novel anhydride derivative, 3-acetoxy-2-methylbenzoic anhydride (AMA), obtained from the interaction of 3-acetoxy-2-methylbenzoyl chloride with 3-acetoxy-2-methylbenzoic acid. The synthesized compound was characterized by elemental analysis, IR, 1H NMR, and 13C NMR spectroscopic studies and single-crystal X-ray crystallography which revealed the crystallization of AMA as monoclinic with space group P21/c. A Hirshfeld surface analysis was performed to record various intermolecular interactions, indicating the stabilization of the AMA structure by the intermolecular weak C-H···O hydrogen bonds and π···π interactions. The title compound was screened for antibacterial and antifungal activities using a serial dilution technique under aseptic conditions. The results indicate that the title compound has significant antibacterial properties but showed no antifungal behavior.

Synthesis, Structural Investigation, Hirshfeld Surface Analysis, and Biological Evaluation of N-(3-Cyanothiophen-2-yl)-2-(thiophen-2-yl)acetamide.

In this study, a novel heterocyclic amide derivative, N-(3-cyanothiophen-2-yl)-2-(thiophen-2-yl)acetamide (I), was obtained by reacting 2-aminothiophene-3-carbonitrile with activated 2-(thiophen-2-yl)acetic acid in a N-acylation reaction and characterized by elemental analyses, FT-IR, 1H and 13C NMR spectroscopic studies, and single crystal X-ray crystallography. The crystal packing of I is stabilized by C-H···N and N-H···N hydrogen bonds. In addition, I was investigated computationally using the density functional theory (DFT) method with the B3LYP exchange and correlation functions in conjunction with the 6311++G(d,p) basis set in the gas phase. Fukui function (FF) analysis was also carried out. Electrophilicity-based charge transfer (ECT) method and charge transfer (ΔN) were computed to examine the interactions between I and DNA bases (such as guanine, thymine, adenine, and cytosine). The most important contributions to the Hirshfeld surface are H···H (21%), C···H (20%), S···H (19%), N···H (14%), and O···H (12%). An ABTS antioxidant assay was used to evaluate the in vitro antioxidant activity of I. The compound exhibited moderate antioxidant activity. The antimicrobial activity of the title molecule was investigated under aseptic conditions, using the microdilution method, against Gram-positive and Gram-negative bacterial strains, and it also demonstrated significant activity against yeasts (Candida glabrata ATCC 90030, Candida krusei ATCC 34135). The findings revealed that the molecule possesses significant antioxidant and antimicrobial properties.

Growth, crystal structure, Hirshfeld surface analysis, DFT studies, physicochemical characterization, and cytotoxicity assays of novel organic triphosphate.

A novel organic-inorganic hybrid compound, named (1-phenylpiperazinium) trihydrogen triphosphate, with the formula (C10H15N2)2H3P3O10 has been obtained by low speed of evaporation of a mixture of an alcoholic solution of 1-phenylpiperazine and triphosphoric acid H5P3O10 at room temperature after using the ion exchange chemical procedure. To carry out a detailed crystallographic structure analysis, single-crystal X-ray diffraction has been reported. In the molecular arrangement, the different entities are held together through N-H…O, O-H…O, and C-H…O hydrogen bonds, building up a three-dimensional packing. Powder X-ray diffraction analysis is acquired to confirm the purity of the product. The nature and the proportion of intermolecular interactions were investigated by Hirshfeld surface analysis. In order to support the experimental results, a density functional theory (DFT) calculation was performed, using the Becke-3-parameter-Lee-Yang-Parr (B3LYP) function with LANL2DZ basis set, and the data indicate much agreement between the experimental and the theoretical results. Thus, the physicochemical properties were studied employing a variety of techniques (FTIR, NMR, UV-visible, and photoluminescence). To get an insight of the possible employment of the present material in biology, cell viability assays were performed.

Crystal structure and Hirshfeld surface analysis of 3-(hy-droxy-meth-yl)-3-methyl-2,6-di-phenyl-piperidin-4-one.

A new synthesis of the title compound, C19H21NO2, was developed with good yield and purity using the reaction of 4-hy-droxy-3-methyl-2-butanone, benzaldehyde and ammonium acetate in glacial acetic acid as a solvent. The central piperidine ring adopts a chair conformation, and its least-squares basal plane forms dihedral angles of 85.71 (11) and 77.27 (11)° with the terminal aromatic rings. In the crystal, the mol-ecules are linked by O-H⋯O and C-H⋯O hydrogen bonds into double ribbons. The Hirshfeld surface analysis shows that the most important contributions are from H⋯H (68%), C⋯H/H⋯C (19%) and O⋯H/H⋯O (12%) inter-actions.

Crystal structure and Hirshfeld surface analysis of 6,6'-((1E,1'E)-{[1,4-phenyl-enebis(methyl-ene)]bis(aza-nylyl-idene)}bis-(methane-ylyl-idene))bis-(2-meth-oxy-phenol).

The Schiff base compound, C24H24N2O4, was synthesized by the inter-action of 2-hy-droxy-3-meth-oxy benzaldehyde and 1,4-benzene dimethanamine in ethanol, and crystallizes in the monoclinic space group P21/n with Z' = 0.5. The mol-ecule is not planar, the 1,4-di-ethyl-benzene and the phenol rings are twisted with respect to each other, making a dihedral angle of 74.27 (5)°. The mol-ecular structure is stabilized by an O-H⋯N hydrogen bond, forming an S(6) ring motif. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds, resulting in the formation of sheets parallel to the bc plane. A Hirshfeld surface analysis was undertaken to investigate the various inter-molecular contacts controlling the supra-molecular topology, suggesting the H⋯O (18%) contacts to be the most significant inter-actions, whereas the H⋯H (50.5%) and C⋯H (24.3%) inter-actions are less significant.

Crystal structure and mol-ecular docking study of diethyl 2,2'-({[(1E,1'E)-(hydrazine-1,2-diyl-idene)bis-(methanylyl-idene)]bis-(4,1-phenyl-ene)}bis-(-oxy))di-acetate.

The title Schiff base, C22H24N2O6, adopts an E configuration. The mol-ecule is planar, the mean planes of the phenyl ring system (r.m.s deviation = 0.0059 Å) forms a dihedral angle of 0.96 (4)° with the mean plane of the phenyl ring moiety (r.m.s deviation = 0.0076 Å). In the crystal, mol-ecules are linked by weak inter-molecular C-H⋯O and C-H⋯N hydrogen bonds into chains extending along the c-axis and b-axis directions, respectively. A mol-ecular docking study between the title mol-ecule and 5-HT2C, which is a G protein receptor and ligand-gated ion channels found in nervous systems (PDB ID: 6BQH) was executed. The experiment shows that it is a good potential agent because of its affinity and ability to stick to the active sites of the receptor.

Crystal structure and Hirshfeld surface analysis of (Z)-2-{[(2,4-di-methyl-phen-yl)imino]-meth-yl}-4-methyl-phenol.

The title compound, C16H17NO, is a Schiff base that exists in the enol-imine tautomeric form and adopts a Z configuration. The mol-ecule is non-planar, with the twisted rings making a dihedral angle of 39.92 (4)°. The intra-molecular O-H⋯N hydrogen bond forms an S(6) ring motif. In the crystal, mol-ecules are linked by C-H⋯π inter-actions and very weak π-π stacking inter-actions also help to consolidate the crystal packing. A Hirshfeld surface analysis was performed to investigate the contributions of different inter-molecular contacts within the supra-molecular structure. The major contributions are from H⋯H (65%), C⋯H (19.2%) and O⋯H (6.6%) inter-actions.

Crystal structure and Hirshfeld surface analysis of bis-[(eth-oxy-methane-thio-yl)sulfanido](N,N,N',N'-tetra-methyl-ethane-1,2-di-amine)-mercury(II).

The title four-coordinate mononuclear complex, [Hg(C3H5OS2)2(C6H16N2)] or [Hg(C3H5OS2)2(tmeda)] (tmeda: N,N,N',N'-tetra-methyl-ethane-1,2-di-amine), has a distorted tetra-hedral geometry. The HgII ion is coordinated to two N atoms of the N,N,N',N'-tetra-methyl-ethylenedi-amine ligand and two S atoms from two ethylxanthate xanthate ligands. In the crystal, mol-ecules are linked by weak C-H⋯S hydrogen bonds, forming a two-dimensional supra-molecular architecture in the ab plane. The most important contributions for the crystal packing are from H⋯H (59.3%), S⋯H (27.4%) and O⋯H (7.5%) inter-actions.

Crystal structure and Hirshfeld surface analysis of 2-{[(E)-(3-cyclo-butyl-1H-1,2,4-triazol-5-yl)imino]-meth-yl}phenol.

The title compound, C13H14N4O, was developed using the reaction of salicyl-aldehyde and 3-amino-5-cyclo-butyl-1,2,4-triazole in ethanol under microwave irradiation. This eco-friendly microwave-promoted method proved to be efficient in the synthesis of 2-{[(E)-(3-cyclo-butyl-1H-1,2,4-triazol-5-yl)imino]-meth-yl}phenol in good yields and purity. The title compound is a Schiff base that exists in the phenol-imine tautomeric form and adopts an E configuration. The three independent mol-ecules in the asymmetric unit (A, B and C) are not planar, the cyclo-butyl and the phenol-imine rings are twisted to each other making a dihedral angle of 67.8 (4)° in mol-ecule A, 69.1 (2)° in mol-ecule B and 89.1 (2)° in mol-ecule C. In each mol-ecule an intra-molecular O-H⋯N hydrogen bond is present, forming an S(6) ring motif. A Hirshfeld surface analysis was performed to investigate the contributions of the different inter-molecular contacts within the supra-molecular structure. The major inter-actions are H⋯H (53%), C⋯H (19%) and N⋯H (17%) for mol-ecule A, H⋯H (50%), N⋯H (20%) and C⋯H (20%) for mol-ecule B and H⋯H (57%), C⋯H (14%) and N⋯H (13%) for mol-ecule C.

Crystal structure and mol-ecular docking study of (E)-2-{[(E)-2-hy-droxy-5-methyl-benzyl-idene]hydrazinyl-idene}-1,2-di-phenyl-ethan-1-one.

The title compound, C22H18N2O2, is a Schiff base that exists in the phenol-imine tautomeric form and adopts an E configuration with respect to the C=N bond. The mol-ecular structure is stabilized by an O-H⋯N hydrogen bond, forming an S(6) ring motif. In the crystal, pairs of C-H⋯O hydrogen bonds link the mol-ecules to form inversion dimers. Weak π-π stacking inter-actions along the a-axis direction provide additional stabilization of the crystal structure. The mol-ecule is non-planar, the aromatic ring of the benzaldehyde residue being nearly perpendicular to the phenyl and 4-methyl-phenol rings with dihedral angles of 88.78 (13) and 82.26 (14)°, respectively. A mol-ecular docking study between the title mol-ecule and the COVID-19 main protease (PDB ID: 6LU7) was performed, showing that it is a potential agent because of its affinity and ability to adhere to the active sites of the protein.

Crystal structure and Hirshfeld surface analysis of a copper(II) complex containing 2-nitro-benzoate and tetra-methyl-ethylenedi-amine ligands.

The reaction of copper(II) sulfatepentahydrate with 2-nitro-benzoic acid and N,N,N',N'-tetra-methyl-ethylenedi-amine (TMEDA) in basic solution produces the complex bis-(2-nitro-benzoato-κO)(N,N,N',N'-tetra-methyl-ethylenedi-amine-κ2 N,N')copper(II), [Cu(C7H4NO4)2(C6H16N2)] or [Cu(2-nitro-benzoate)2(tmeda)]. Each carboxyl-ate group of the 2-nitro-benzoate ligand is coordinated by CuII atom in a monodentate fashion and two TMEDA ligand nitro-gen atoms are coordinate by the metal center, giving rise to a distorted square-planar coordination environment. In the crystal, metal complexes are linked by centrosymmetric C-H⋯O hydrogen bonds, forming ribbons via a R 2 2(10) ring motif. These ribbons are linked by further C-H⋯O hydrogen bonds, leading to two-dimensional hydrogen-bonded arrays parallel to the bc plane. Weak π-π stacking inter-actions provide additional stabilization of the crystal structure. Hirshfeld surface analysis, dnorm and two-dimensional fingerprint plots were examined to verify the contributions of the different inter-molecular contacts within the supra-molecular structure. The major inter-actions of the complex are O⋯H/H⋯O (44.9%), H⋯H (34%) and C⋯H (14.5%).

Crystal structure and Hirshfeld surface analysis of 2-methyl-3-nitro-N-[(E)-(5-nitro-thio-phen-2-yl)methyl-idene]aniline.

The title compound, C12H9N3O4S, synthesized by condensation of 5-nitro-thio-phene-2-carbaldehyde and 2-methyl-3-nitro-aniline, crystallizes in the ortho-rhom-bic space group P212121. In the mol-ecule, the aromatic benzene and thio-phene rings are twisted with respect to each other, making a dihedral angle of 23.16 (7)°. In the crystal, mol-ecules are linked by inter-molecular C-H⋯O hydrogen bonds into chains extending along the c-axis direction. Weak π-π stacking inter-actions along the a-axis direction provide additional stabilization of the crystal structure. The roles of the various inter-molecular inter-actions were clarified by Hirshfeld surface analysis, which reveals that the crystal packing is dominated by O⋯H (39%) and H⋯H (21.3%) contacts. The crystal studied was refined as a two-component inversion twin.

Crystal structure and Hirshfeld surface analysis of (E)-2-{[(2-iodo-phen-yl)imino]-meth-yl}-6-methyl-phenol.

The title compound, C14H12INO, was synthesized by condensation of 2-hy-droxy-3-methyl-benzaldehyde and 2-iodo-aniline, and crystallizes in the ortho-rhom-bic space group P212121. The 2-iodo-phenyl and benzene rings are twisted with respect to each other, making a dihedral angle of 31.38 (2)°. The mol-ecular structure is stabilized by an O-H⋯N hydrogen bond, forming an S(6) ring motif. In the crystal, mol-ecules are linked by C-H⋯π inter-actions, resulting in the formation of sheets along the a-axis direction. Within the sheets, very weak π-π stacking inter-actions lead to additional stabilization. The Hirshfeld surface analysis and fingerprint plots reveal that the crystal structure is dominated by H⋯H (37.1%) and C⋯H (30.1%) contacts. Hydrogen bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. The crystal studied was refined as a two-component inversion twin.

Crystal structure and Hirshfeld surface analysis of one-dimensional copper(II) coordination polymer incorporating succinate and tetra-methyl-ethylene-diamine ligands.

The reaction of copper nitrate with succinic acid (succH) and N,N,N',N'-tetra-methyl-ethylenedi-amine (TMEDA) in basic solution produces the complex catena-poly[[[(N,N,N',N'-tetra-methyl-ethylenedi-amine-κ2 N,N')copper(II)]-µ-succinato-κ2 O 1:O 4] tetra-hydrate], {[Cu(C4H4O4)(C6H16N2)]·4H2O} n or {[Cu(succ)(tmeda)]·4H2O} n . Each carboxyl-ate group of the succinate ligand coordinates to a CuII atom in a monodentate fashion, giving rise to a distorted square-planar geometry. The succinate ligands bridge the CuII centres, forming one-dimensional polymeric chains. Hydrogen bonds between the ligands and water mol-ecules link these chains into sheets that lie parallel to the ac plane. Hirshfeld surface analysis, d norm and two-dimensional fingerprint plots were examined to verify the contributions of the different inter-molecular contacts within the supra-molecular structure.

Two new zinc(II) and mercury(II) complexes based on N,N'-(cyclohexane-1,2-diylidene)bis(4-fluorobenzohydrazide): synthesis, crystal structures and antibacterial activities.

Reaction of N,N'-(cyclohexane-1,2-diylidene)bis(4-fluorobenzohydrazide), C20H18F2N4O2, (LF), with zinc chloride and mercury(II) chloride produced different types and shapes of neutral coordination complexes, namely, dichlorido[N,N'-(cyclohexane-1,2-diylidene)bis(4-fluorobenzohydrazide)-κ2N,O]zinc(II), [ZnCl2(C20H18F2N4O2)], (1), and dichlorido[N,N'-(cyclohexane-1,2-diylidene)bis(4-fluorobenzohydrazide)-κ4O,N,N',O']mercury(II), [HgCl2(C20H18F2N4O2)], (2). The organic ligand and its metal complexes are characterized using various techniques: IR, UV-Vis and nuclear magnetic resonance (NMR) spectroscopies, in addition to powder X-ray diffraction (PXRD), single-crystal X-ray crystallography and microelemental analysis. Depending upon the data from these analyses and measurements, a typical tetrahedral geometry was confirmed for zinc complex (1), in which the ZnII atom is located outside the bis(benzhydrazone) core. The HgII atom in (2) is found within the core and has a common octahedral structure. The in vitro antibacterial activities of the prepared compounds were evaluated against two different bacterial strains, i.e. gram positive Bacillus subtilis and gram negative Pseudomonas aeruginosa bacteria. The prepared compounds exhibited differentiated growth-inhibitory activities against these two bacterial strains based on the difference in their lipophilic nature and structural features.

Crystal structure and Hirshfeld surface analysis of hexyl 1-hexyl-2-oxo-1,2-di-hydro-quinoline-4-carboxyl-ate.

The asymmetric unit of the title compound, C22H31NO3, comprises of one mol-ecule. The mol-ecule is not planar, with the carboxyl-ate ester group inclined by 33.47 (4)° to the heterocyclic ring. Individual mol-ecules are linked by aromaticC-H⋯Ocarbon-yl hydrogen bonds into chains running parallel to [001]. Slipped π-π stacking inter-actions between quinoline moieties link these chains into layers extending parallel to (100). Hirshfeld surface analysis, two-dimensional fingerprint plots and mol-ecular electrostatic potential surfaces were used to qu-antify the inter-molecular inter-actions present in the crystal, indicating that the most important contributions for the crystal packing are from H⋯H (72%), O⋯H/H⋯O (14.5%) and C⋯H/H⋯C (5.6%) inter-actions.

Crystal structure and Hirshfeld surface analysis of 2-amino-3-hy-droxy-pyridin-1-ium 6-methyl-2,2,4-trioxo-2H,4H-1,2,3-oxa-thia-zin-3-ide.

The asymmetric unit of the title compound, C5H7N2O+·C4H4NO4S-, contains one cation and one anion. The 6-methyl-2,2,4-trioxo-2H,4H-1,2,3-oxa-thia-zin-3-ide anion adopts an envelope conformation with the S atom as the flap. In the crystal, the anions and cations are held together by N-H⋯O, N-H⋯N, O-H⋯O and C-H⋯O hydrogen bonds, thus forming a three-dimensional structure. The Hirshfeld surface analysis and fingerprint plots reveal that the crystal packing is dominated by O⋯H/H⋯O (43.1%) and H⋯H (24.2%) contacts.

Crystal structure and Hirshfeld surface analysis of a copper(II) complex with ethyl-enedi-amine and non-coordinated benzoate.

In the title compound, di-aqua-bis-(ethyl-enedi-amine-κ2 N,N')copper(II) bis-(2-nitro-benzoate), [Cu(C2H8N2)2(H2O)2](C7H4NO4)2, two di-aqua-bis-(ethyl-enedi-amine)-copper(II) cations and four nitro-benzoate anions are present in the asymmetric unit. All four anions are 'whole-mol-ecule' disordered over two sets of sites. The major components have refined occupancies of 0.572 (13), 0.591 (9), 0.601 (9) and 0.794 (10). The CuII ions exhibit slightly distorted octa-hedral geometries. In the crystal, cations and anions are connected to each other via N-H⋯O and O-H⋯O hydrogen bonds, forming a two-dimensional network parallel to (200). The inter-molecular contacts in the crystal were further analysed using Hirshfeld surface analysis, which indicates that the most significant contacts are O⋯H/H⋯O (42.9%), followed by H⋯H (35.7%), C⋯H/H⋯C (14.2%), C⋯C (2.9%), C⋯O/O⋯C (2.2%), N⋯H/H⋯N (0.9%) and N⋯O/O⋯N (0.3%).

Regio- and diastereoselective synthesis of spiropyrroloquinoxaline grafted indole heterocyclic hybrids and evaluation of their anti-Mycobacterium tuberculosis activity.

An efficient and eco compatible approach for the regio- and stereoselective synthesis of structurally diverse novel hybrid heterocycles comprising spiropyrrolidine, indenoquinoxaline and indole structural units in excellent yields, has been achieved through a one-pot multicomponent process involving 1,3-dipolar cycloaddition as a key step. The 1,3-dipolar component is the azomethine ylide generated in situ from indenoquinoxaline and l-tryptophan and reacts with various substituted ß-nitrostyrenes affording the spiroheterocyclic hybrids. The ring system thus created possesses two C-C and three C-N bonds and four adjacent stereogenic carbons, one of which is quaternary and the reaction proceeded with full diastereomeric control. All the synthesized compounds were assayed for their in vitro activity against Mycobacterium tuberculosis H37Rv using MABA assay. Interestingly, the compound bearing a 2-fluoro substituent on the aryl ring displayed an equipotent activity (MIC 1.56 µg mL-1) to ethambutol against Mycobacterium tuberculosis H37Rv.