Crystal structure and Hirshfeld surface analysis of ethyl 2-(7-chloro-3-methyl-2-oxo-1,2-di-hydro-quinoxalin-1-yl)acetate.

The quinoxaline moiety in the title mol-ecule, C13H13ClN2O3, is almost planar (r.m.s. deviation of the fitted atoms = 0.033 Å). In the crystal, C-H⋯O hydrogen bonds plus slipped π-stacking and C-H⋯π(ring) inter-actions generate chains of mol-ecules extending along the b-axis direction. The chains are connected by additional C-H⋯O hydrogen bonds. Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯H (37.6%), H⋯O/O⋯H (22.7%) and H⋯Cl/Cl⋯H (13.1%) inter-actions.

Crystal structure and Hirshfeld surface analysis of 2,4,6-tri-amino-pyrimidine-1,3-diium dinitrate.

The title compound, C4H9N5 2+·2NO3 -, crystallizes in the monoclinic crystal system, space group P21/c. The asymmetric unit, which comprises a diprotonated tri-amino-pyrimidine dication and two nitrate anions, has an almost planar geometry with a dihedral angle of 0.92 (4)° between the mean plane of the cation and that defined by both anions. In the crystal, hydrogen-bonding inter-actions between the 2,4,6-tri-amino-pyrimidine cation and the nitrate anions lead to a one-dimensional supra-molecular network with weak anionic inter-actions forming a three-dimensional network. These inter-actions were investigated using Hirshfeld surface analysis, which indicates that the most important contributions for the packing arrangement are from O⋯H/H⋯O (53.2%), N⋯H/H⋯N (12.5%) and C⋯H/H⋯C (9.6%) inter-actions. Energy framework analysis showed that of the components of the framework energies, electrostatic repulsion (E rep) is dominant.

Crystal structure and Hirshfeld surface analysis of dimethyl 3,3'-{[(1E,2E)-ethane-1,2-diyl-idene]bis(aza-nylyl-idene)}bis-(4-methyl-benzoate).

The title Schiff base compound, C20H20N2O4, synthesized by the condensation reaction of methyl 3-amino-4-methyl-benzoat and glyoxal in ethanol, crystallizes in the the monoclinic space group P21/n. The mol-ecule is Z-shaped with the C-N-C-C torsion angle being 47.58 (18)°. In the crystal, pairs of mol-ecules are linked via C-H⋯N hydrogen bonds, forming centrosymetric dimers with an R 2 2(8) ring motif; this connectivity leads to the formation of columns running along the a-axis direction. Hirshfeld surface analysis and two-dimensional fingerprint plots were used to explore the inter-molecular inter-actions and revealed that the most significant contributions to the crystal packing are from H⋯H (49.4%), H⋯O/O⋯H (19.0%) and H⋯C/C⋯H (17.5%) contacts. Energy frameworks were constructed through different inter-molecular inter-action energies to investigate the stability of the compound. The net inter-action energies for the title compound were found to be electrostatic (E ele = -48.4 kJ mol-1), polarization (E pol = -9.7 kJ mol-1), dispersion (E dis = -186.9 kJ mol-1) and repulsion (E rep = 94.9 kJ mol-1) with a total inter-action energy, E tot, of -162.4 kJ mol-1.

Crystal structure of (E)-3-({6-[2-(4-chloro-phen-yl)ethen-yl]-3-oxo-2,3-di-hydro-pyridazin-4-yl}meth-yl)pyridin-1-ium chloride dihydrate.

In the title compound, C18H15ClN3O+·Cl-·2H2O, three intra-mol-ecular hydrogen bonds are observed, N-H⋯O, O-H⋯Cl and O-H⋯O. In the crystal, mol-ecules are connected by C-H⋯Cl and N-H⋯O hydrogen bonds. Strong C-H⋯Cl, N-H⋯O, O-H⋯Cl and O-H⋯O hydrogen-bonding inter-actions are implied by the Hirshfeld surface analysis, which indicate that H⋯H contacts make the largest contribution to the overall crystal packing at 33.0%.

Crystal structure and Hirshfeld surface analysis of (Z)-4-{[4-(3-methyl-3-phenyl-cyclo-but-yl)thia-zol-2-yl]amino}-4-oxobut-2-enoic acid.

The title cyclo-butyl compound, C18H18N2O3S, was synthesized by the inter-action of 4-(3-methyl-3-phenyl-cyclo-but-yl)thia-zol-2-amine and maleic anhydride, and crystallizes in the ortho-rhom-bic space group P212121 with Z' = 1. The mol-ecular geometry is partially stabilized by an intra-molecular N-H⋯O hydrogen bond forming an S 1 1(7) ring motif. The mol-ecule is non-planar with a dihedral angle of 88.29 (11)° between the thia-zole and benzene rings. In the crystal, the mol-ecules are linked by O-H⋯N hydrogen bonds, forming supra-molecular ribbons with C 1 1(9) chain motifs. To further analyze the inter-molecular inter-actions, a Hirshfeld surface analysis was performed. The results indicate that the most important contributions to the overall surface are from H⋯H (43%), C⋯H (18%), O⋯H (17%) and N⋯H (6%), inter-actions.

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 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 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 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.

Synthesis, crystal structure and Hirshfeld surface analysis of 1,7-dimethyl-5a,6,11a,12-tetra-hydro-benzo[b]benzo[5,6][1,4]oxazino[2,3-e][1,4]oxazine.

Mol-ecules of the title compound, C16H16N2O2, occupy special positions on the twofold rotation axes. The heterocyclic ring adopts a slightly twisted envelope conformation with one of the two junction carbon atoms as the flap. The mean planes through the two halves of the mol-ecule form a dihedral angle of 72.01 (2)°. In the crystal, mol-ecules are linked by pairs of C-H⋯O and N-H⋯C contacts into layers parallel to (100). H⋯H contacts make the largest contribution to the Hirshfeld surface (58.9%).

Synthesis, crystal structures and Hirshfeld surface analysis of 1,4-dibenzyl-6-methyl-1,4-di-hydro-quinoxaline-2,3-dione.

The title quinoxaline mol-ecule, C23H20N2O2, is not planar, the dihedral angle angle between the mean planes of the benzene rings being 72.54 (15)°. In the crystal, mol-ecules are connected into chains extending parallel to (10) by weak C-H⋯O hydrogen bonds. Weak C-H⋯π inter-actions link the chains, forming a three-dimensional network structure. Hirshfeld surface analysis revealed that the most important contributions for the crystal packing are from H⋯H (48.7%), H⋯C/C⋯H (32.0%), H⋯O/O⋯H (15.4%), C⋯C (1.9%), H⋯N/N⋯H (1.1%) contacts.