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The electrification of the transport sector together with an increasing share of renewable energies has the potential to reduce CO2 emissions significantly. This transformation requires the rollout of charging infrastructure, which has an impact on power grids. For grid planning and dimensioning purposes, it is crucial to assess this rapidly growing impact. We present an approach using socio-economic data such as income levels together with a model for demographic changes to estimate where electric mobility is likely to be concentrated, especially during the transformation phase. We present a total-cost-of-ownership approach for the ramp-up of electric mobility, considering an increased penetration of renewable energies. With the city of Wiesbaden in Germany as an example for an application area, the possible expansion of vehicle ownership and charging points is modeled on the level of individual buildings. Compared to a simpler approach, the detailed model results in more consistent charging point allocations, higher line/transformer loadings and lower bus voltages for the investigated grids. Predicting future distributions of charging points with such a level of detail in terms of ramp-up and spatial resolution proves potentially beneficial for grid analysis and planning purposes, especially in urban areas, where infrastructure changes are expensive and time-consuming. [ABSTRACT FROM AUTHOR]

The title coordination polymer, [Co(N 3 ) 2 (C 9 H 8 N 2 )] n , was synthesized solvothermally. The Co II atom exhibits a distorted octa-hedral [CoN 6 ] coordination geometry with a bidentate 8-amino-quinoline ligand and four azide ligands. Bridging azide ligands result in chains extending along [100]. N-H⋯N hydrogen bonds join the chains to give an extended structure with sheets parallel to (002)., (© Setifi et al. 2024.)

The title compound, [Cu(C 9 H 5 N 4 O) 2 (C 10 H 9 N 3 ) 2 ], was synthesized solvothermally. The complex exhibits a distorted octa-hedral coordination geometry. The Cu II atom is located on an inversion centre. The distorted octahedral CuN 6 coordination sphere is composed of bidentate 2,2'-dipyrid-ylamine in the equatorial sites while the axial sites are occupied by 1,1,3,3-tetra-cyano-2-eth-oxy-propenide ligands. In the crystal, N-H⋯N hydrogen bonding results in chains parallel to [010]., (© Saadallah et al. 2022.)

The title metal-organic polymer, catena-poly[[(5,5'-dimethyl-2,2'-bipyridine-κ 2 N,N')iron(II)]-di-μ-azido-κ 2 N 1 :N 3 -[(5,5'-dimethyl-2,2'-bipyridine-κ 2 N,N')iron(II)]-di-μ-azido-κ 2 N 1 :N 1 ], [Fe(N 3 ) 2 (C 12 H 12 N 2 )] n , features alternating μ-1,1 (end-on mode of coordination) and μ-1,3 (end-to-end mode of coordination) double azide bridges, forming chains running in the [100] direction. The octahedral coordination geometry around the Fe II centre is completed by a bidentate 5,5'-dimethyl-2,2'-bipyridine ligand. Two polymorphs for this compound were obtained from the crude reaction product, the first in the space group P-1 and the other in P2 1 /c. The molecular and crystal structures are very similar for both forms, the main difference being that the eight-membered Fe(μ-1,3-N 3 ) 2 Fe metallacycle formed with end-to-end azide ligands has a nearly flat conformation in the triclinic form and a chair conformation in the monoclinic form. In spite of this geometric difference, both forms have the same density, the same packing index and similar arrangements of the one-dimensional chains in the crystal. As a consequence, they also share very similar Hirshfeld surfaces and fingerprint plots. However, a density functional theory (DFT) computational study showed that the monoclinic form is more stable than the triclinic form by ca 30.5 kJ mol -1 .

Intramedullary signal change (ISC) is a non-specific finding that is frequently observed on magnetic resonance imaging (MRI) examinations of the canine spinal cord. ISC can represent a variety of primary pathological processes such as neoplasms or myelitides or secondary changes such as edema, cysts, gliosis, or myelomalacia. An unusual phenotype of ISC is the "snake-eye" myelopathy (SEM), which refers to bilaterally symmetric T2 hyperintensities preferentially affecting the ventral horn gray matter on transverse MR images, which resemble a pair of snake's eyes. The pathophysiology of SEM is poorly understood in humans, and this imaging finding may be associated with cervical spondylotic myelopathy, spinal cord ischemia, ossification of the posterior longitudinal ligament, amyotrophic lateral sclerosis, and Hirayama disease. Here we describe four dogs with cervical MRI examinations consistent with an SEM-like phenotype. All dogs initially presented with a central cord syndrome or tetraparesis referable to a C6-T2 neuroanatomic localization, which was attributed to disc-associated spinal cord compression in three cases, while one dog had the SEM-like phenotype with no identifiable etiology. Once the SEM-like phenotype was present on MRI examinations, dogs demonstrated insidious clinical deterioration despite therapeutic interventions. Deterioration was characterized by lower motor neuron weakness and neurogenic muscle atrophy progressing to paralysis in the thoracic limbs, while neurological functions caudal to the level of the SEM-like lesion remained largely preserved for months to years thereafter. Neuropathological features of the SEM-like phenotype include multisegmental cavitations and poliomyelomalacia of laminae VI-IX of the caudal cervical spinal cord, although the lesion evolved into pan-necrosis of gray matter with extension into the adjacent white matter in one case with an 8 years history of progressive disease. Although the pathophysiology of SEM remains unknown, the topographical distribution and appearance of lesions is suggestive of a vascular disorder. As the SEM-like phenotype was uniformly characterized by longitudinally and circumferentially extensive neuronal necrosis, results of this small case series indicate that dogs with clinical signs of central cord syndrome and the SEM-like phenotype involving the cervicothoracic intumescence on MR examinations have a poor prognosis for the preservation or recovery of thoracic limb motor function.

The isostructural salts benzene-1,2-diaminium bis(pyridine-2-carboxylate), 0.5C 6 H 10 N 2 2+ ·C 6 H 4 NO 2 - , (1), and 4,5-dimethylbenzene-1,2-diaminium bis(pyridine-2-carboxylate), 0.5C 8 H 14 N 2 2+ ·C 6 H 4 NO 2 - , (2), and the 1:2 benzene-1,2-diamine-benzoic acid cocrystal, 0.5C 6 H 8 N 2 ·C 7 H 6 O 2 , (3), are reported. All of the compounds exhibit extensive N-H...O hydrogen bonding that results in interconnected rings. O-H...N hydrogen bonding is observed in (3). Additional π-π and C-H...π interactions are found in each compound. Hirshfeld and fingerprint plot analyses reveal the primary intermolecular interactions and density functional theory was used to calculate their strengths. Salt formation by (1) and (2), and cocrystallization by (3) are rationalized by examining pK a differences. The R 2 2 (9) hydrogen-bonding motif is common to each of these structures.

The cocrystal salt tetraaquabis[trans-1,2-bis(pyridin-4-yl)ethene-κN]iron(II) bis(1,1,3,3-tetracyano-2-ethoxypropenide)-trans-1,2-bis(pyridin-4-yl)ethene (1/2), [Fe(C 12 H 10 N 2 ) 2 (H 2 O) 4 ](C 9 H 5 N 4 O) 2 ·2C 12 H 10 N 2 , is a rare example of a mononuclear Fe II compound with trans-1,2-bis(pyridin-4-yl)ethane (bpe) ligands. The complex cation resides on a crystallographically imposed inversion center and exhibits a tetragonally distorted octahedral coordination geometry. Both the symmetry-independent bpe ligand and the cocrystallized bpe molecule are essentially planar. The 1,1,3,3-tetracyano-2-ethoxypropenide counter-ion is nonplanar and the bond lengths are consistant with significant electron delocalization. The extended structure exhibits an extensive O-H...N hydrogen-bonding network with layers of complex cations joined by the cocrystallized bpe. Both the coordinated and the cocrystallized bpe are involved in π-π interactions. Hirshfeld and fingerprint plots reveal the important intermolecular interactions. Density functional theory was used to estimate the strengths of the hydrogen-bonding and π-π interactions, and suggest that the O-H...N hydrogen bonds enhance the strength of the π-interactions by increasing the polarization of the pyridine rings.

Hydrogen bonding plays an important role in the design of solid-state structures and gels with desirable properties. 1-(4-Hydroxybenzyl)-2-(4-hydroxyphenyl)-5,6-dimethyl-1 H -benzimidazole was isolated as the acetone disolvate, C 22 H 20 N 2 O 2 ·2C 3 H 6 O. O-H⋯N hydrogen bonding between benz-imidazole mol-ecules results in chains parallel to [010]. One of the acetone solvate mol-ecules participates in O-H⋯O hydrogen bonding with the benzimidazole derivative. C-H⋯π inter-actions are observed in the extended structure. Hirshfeld surface analysis was used to explore the inter-molecular inter-actions and density functional theory was used to estimate the strength of the hydrogen bonds.

Hydrogen-bonding interactions play an important role in the rational design of crystal systems with desirable architectures. The crystal structures of benzene-1,2-diaminium sulfate sesquihydrate, C 6 H 20 N 2 2+ ·SO 4 2- ·1.5H 2 O, (1), benzene-1,3-diaminium tetrachloridozincate(II), (C 6 H 20 N 2 )[ZnCl 4 ], (3), and 3-aminoanilinium perchlorate, C 6 H 9 N 2 + ·ClO 4 - , (4), are reported. Hydrated salt (1) is a polymorph (space group C2/c) of a previously reported [Anderson et al. (2011). Cryst. Growth Des. 11, 4904-4919] crystalline modification of salt (2) (space group P2 1 /c). The contents of the asymmetric unit of (2) are twice that of (1). In each, the extended structures exhibit hydrogen bonds, resulting in chains of ions and hydrogen-bonded rings with an R 4 4 (8) motif involving water molecules. Hirshfeld surface analysis shows that a significant difference between the two is the degree of C...C interaction. Salt (3) exhibits an extended structure having hydrogen-bonded rings and parallel benzene rings, with a centroid-to-centroid separation of 3.860 (2) Å. Salt (4) displays a three-dimensional superstructure that results from linked planes of ions joined by an extensive hydrogen-bonding network involving N-H...O, N-H...N and C-H...π interactions. The cation-anion and N-H...N interaction energies in (4), determined using density functional theory (DFT), show significantly stronger aminium-perchlorate than amine-perchlorate interactions.

An understanding of the driving forces resulting in crystallization vs organogel formation is essential to the development of modern soft materials. In the mol-ecular structure of the title compound, methyl 10-[4-(4-hydroxyphenyl)phen-oxy]decanoate ( MBO10Me ), C 23 H 30 O 4 , the aromatic rings of the biphenyl group are canted by 6.6 (2)° and the long-chain ester group has an extended conformation. In the crystal, mol-ecules are linked by O-H⋯O hydrogen bonds, forming chains along [10[Formula: see text]]. The chains are linked by C-H⋯O hydrogen bonds, forming layers parallel to the ac plane. The layers are linked by C-H⋯π inter-actions, forming a three-dimensional supra-molecular structure. The extended structure exhibits a lamellar sheet arrangement of mol-ecules stacking along the b -axis direction. Each mol-ecule has six nearest neighbors and the seven-mol-ecule bundles stack to form a columnar superstructure. Inter-action energies within the bundles are dominated by dispersion forces, whereas inter-columnar inter-actions have a greater electrostatic component.

Because the factors favoring the formation of well-formed single crystals are dissimilar to those conducive to gel formation, few examples of single-crystal structural characterizations of organogelators are found in the literature. A series of biphenyl methyl and ethyl diester derivatives of varying chain length were synthesized and their gelation abilities explored. X-ray diffraction of single crystals of one of the gelators reveals a columnar extended structure. Based on XRD results for xerogels obtained from the reported organogelators, the members of the series are isostructural and so also adopt a columnar superstructure. Scanning electron microscopy (SEM) was used for the investigation of the morphology of the xerogels, which display either platelet-like morphologies or more typical entangled twisted ribbon-like aggregates. The gels exhibit chirality, which depends on the sol-gel transition history, as observed by induced circular dichroism (ICD) spectroscopy.

Copper(II) complexes of benzimidazole are known to exhibit biological activity that makes them of inter-est for chemotherapeutic and other pharmaceutical uses. The complex bis-(acetato-κ O ){5,6-dimethyl-2-(pyridin-2-yl)-1-[(pyridin-2-yl)meth-yl]-1 H -benzimidazole-κ 2 N 2 , N 3 }copper(II), has been prepared. The absorption spectrum has features attributed to intra-ligand and ligand-field transitions and the complex exhibits ligand-centered room-temperature luminescence in solution. The aceto-nitrile monosolvate, [Cu(C 2 H 3 O 2 ) 2 (C 20 H 18 N 4 )]·C 2 H 3 N ( 1 ), and the ethanol hemisolvate, [Cu(C 2 H 3 O 2 ) 2 (C 20 H 18 N 4 )]·0.5C 2 H 6 O ( 2 ), have been structurally characterized. Compound 2 has two copper(II) complexes in the asymmetric unit. In both 1 and 2 , distorted square-planar N 2 O 2 coordination geometries are observed and the Cu-N(Im) bond distance is slightly shorter than the Cu-N(py) bond distance. Inter-molecular π-π inter-actions are found in 1 and 2 . A weak C-H⋯π inter-action is observed in 1 .

There are few examples of single-crystal structure determinations of gelators, as gel formation requires that the dissolved gelator self-assemble into a three-dimensional network structure incorporating solvent via noncovalent interactions rather than self-assembly followed by crystallization. In the solid-state structures of the isostructural compounds 4,4'-bis[5-(methoxycarbonyl)pentyloxy]biphenyl (BBO6-Me), C 26 H 34 O 6 , and 4,4'-bis[5-(ethoxycarbonyl)pentyloxy]biphenyl (BBO6-Et), C 28 H 38 O 6 , the molecules sit on a crystallographically imposed center of symmetry, resulting in strictly coplanar phenyl rings. BBO6-Me behaves as an organogelator in various alcohol solvents, whereas BBO6-Et does not. The extended structure reveals bundles of molecules that form a columnar superstructure. Framework-energy calculations reveal much stronger interaction energies within the columns (-52 to -78 kJ mol -1 ) than between columns (-2 to -16 kJ mol -1 ). The intracolumnar interactions are dominated by a dispersion component, whereas the intercolumnar interactions have a substantial electrostatic component.

The photophysical properties of transition metal complexes of the 5,6-dimethyl-2-(pyridin-2-yl)-1-(pyridin-2-ylmethyl)-1H-benzimidazole ligand are of interest. Dichlorido[5,6-dimethyl-2-(pyridin-2-yl)-1-(pyridin-2-ylmethyl)-1H-benzimidazole-κ 2 N 2 ,N 3 ]platinum(II), [PtCl 2 (C 20 H 18 N 4 )], is luminescent in the solid state at room temperature. The compound displays a distorted square-planar coordination geometry. The Pt-N(imidazole) bond length is shorter than the Pt-N(pyridine) bond length. The extended structure reveals that symmetry-related molecules display weak C-H...N, C-H...Cl, and C-H...Pt hydrogen-bonding interactions that are clearly discernable in the Hirshfeld surface and fingerprint plots. The intermolecular C-H...Pt and C-H...N interactions have been explored using density functional theory. The result of an analysis of the distance dependence of C-H...Pt yields a value consistent with that observed in the solid-state structure. The energy of interaction for the C-H...Pt interaction is found to be about -11 kJ mol -1 .

The synthesis of a novel benzimidazole derivative with a long-chain-ester substituent, namely methyl 8-[4-(1H-benzimidazol-2-yl)phenoxy]octanoate, (3), is reported. Ester (3) shows evidence of aggregation in solution and weak gelation ability with toluene. The octan-1-ol solvate, methyl 8-[4-(1H-benzimidazol-2-yl)phenoxy]octanoate octan-1-ol monosolvate, C 22 H 26 N 2 O 3 ·C 8 H 18 O, (4), exhibits a four-molecule hydrogen-bonded motif in the solid state, with N-H...O hydrogen bonds between benzimidazole molecules and O-H...N hydrogen bonds between the octan-1-ol solvent molecules and the benzimidazole unit. The alkyl chains of the ester and the octan-1-ol molecules are in unfolded conformations. The phenylene ring is canted by 10.27 (6)° from the plane of the benzimidazole ring system. H...C contacts make up 20.7% of the Hirshfeld surface coverage. Weak C-H...π interactions involving the benzimidazole alkyl chain and three aromatic rings are observed.

Poly[tetra-μ 2 -acetato-κ 8 O : O '-bis-(μ 2 -benzene-1,2-di-amine-κ 2 N : N ')dicadmium], [Cd 2 (CH 3 COO) 4 (C 6 H 8 N 2 ) 2 ] n , (I), and poly[[(μ 2 -acetato-κ 2 O : O ')(acetato-κ 2 O , O ')(μ 2 -benzene-1,3-di-amine-κ 2 N : N ')cadmium] hemihydrate], {[Cd(CH 3 COO) 2 (C 6 H 8 N 2 )]·0.5H 2 O} n , (II), have two-dimensional polymeric structures in which monomeric units are joined by bridging acetate and benzenedi-amine ligands. Each of the Cd II ions has an O 4 N 2 coordination environment. The coordination geometries of the symmetry-independent Cd II ions are distorted octa-hedral and distorted trigonal anti-prismatic in (I) and distorted anti-prismatic in (II). Both compounds exhibit an intra-layer hydrogen-bonding network. In addition, the water of hydration in (II) is involved in inter-layer hydrogen bonding.

The structural characterization of several polymorphic forms of a compound allow the interplay between molecular conformation and intermolecular interactions to be studied, which can contribute to the development of strategies for the rational preparation of materials with desirable properties and the tailoring of intermolecular interactions to produce solids with predictable characteristics of interest in crystal engineering. The crystal structures of two new polymorphs of 5,6-dimethyl-2-(pyridin-2-yl)-1-[(pyridin-2-yl)methyl]-1H-benzimidazole, C 20 H 18 N 4 , are reported. The previously reported polymorph, (1) [Geiger & DeStefano (2014). Acta Cryst. E70, o365], exhibits the space group C2/c, whereas polymorphs (2) and (3) presented here are in the Pnma and P-1 space groups, respectively. The molecular structures of the three forms differ in their orientations of the 2-(pyridin-2-yl)- and 1-[(pyridin-2-yl)methyl]- substituents. Density functional theory (DFT) calculations show that the relative energies of the molecule in the three conformations follows the order (1) < (2) < (3), with a spread of 10.6 kJ mol -1 . An analysis of the Hirshfeld surfaces shows that the three polymorphs exhibit intermolecular C-H...N interactions, which can be classified into six types. Based on DFT calculations involving pairs of molecules having the observed interactions, the C-H...N energy in the systems explored is approximately -11.2 to -14.4 kJ mol -1 .

The asymmetric unit of the title compound, 2C 5 H 3 ClO 2 S·C 10 H 8 N 2 , is comprised of a mol-ecule of 3-chloro-thio-phene-2-carb-oxy-lic acid (3TPC) and half of a mol-ecule of 4,4'-bi-pyridine (BPY). A distinctive O-H⋯N-based synthon is present. Cl⋯Cl and π-π stacking inter-actions further stabilize the crystal structure, forming a two-dimensional network parallel to the bc plane.

The structures of two zinc complexes containing bidentate benzene-1,2-di-amine ligands are reported. (Benzene-1,2-di-amine-κ(2) N,N')di-chloro-idozinc, [ZnCl2(C6H8N2)], (I), displays a distorted tetra-hedral coordination sphere for the metal cation. The di-amine ligand and the Zn atom reside on a crystallographic mirror plane. In the 1:1 co-crystal salt trans-di-aqua-bis-(4,5-di-methyl-benzene-1,2-di-amine-κ(2) N,N')zinc chloride-4,5-di-methyl-benzene-1,2-di-amine (1/1), [Zn(C8H12N2)2(H2O)2]Cl2·2C8H12N2, (II), the zinc(II) complex cation exhibits a tetra-gonally distorted octa-hedral coordination sphere. The Zn atom sits on a crystallographically imposed inversion center and the di-amine ligands are tilted 30.63 (6)° with respect to the ZnN4 plane. Both complexes exhibit extensive hydrogen bonding. In (I), a stacked-sheet extended structure parallel to (101) is observed. In (II), the co-crystallized di-amine is hydrogen-bonded to the complex cation via O-H⋯N and N-H⋯N linkages. These units are in turn linked into planes along (200) by O-H⋯Cl and N-H⋯Cl hydrogen bonds.

Polynitrile anions are important in both coordination chemistry and molecular materials chemistry, and are interesting for their extensive electronic delocalization. The title compound crystallizes with two symmetry-independent half 4,4'-bipyridine-1,1'-diium (bpyH2(2+)) cations and two symmetry-independent 1,1,3,3-tetracyano-2-ethoxypropenide (tcnoet(-)) anions in the asymmetric unit. One of the bpyH2(2+) ions is located on a crystallographic twofold rotation axis (canted pyridine rings) and the other is located on a crystallographic inversion center (coplanar pyridine rings). The ethyl group of one of the tcnoet(-) anions is disordered over two sites with equal populations. The extended structure exhibits two separate N-H···NC hydrogen-bonding motifs, which result in a sheet structure parallel to (010), and weak C-H···NC hydrogen bonds form joined rings. Two types of multicenter CN···π interactions are observed between the bpyH2(2+) rings and tcnoet(-) anions. An additonal CN···π interaction between adjacent tcnoet(-) anions is observed. Using density functional theory, the calculated attractive energy between cation and anion pairs in the tcnoet(-)···π(bipyridinediium) interactions were found to be 557 and 612 kJ mol(-1) for coplanar and canted bpyH2(2+) cations, respectively.

The synthesis and structural characterization of 2-(furan-2-yl)-1-(furan-2-ylmethyl)-1H-benzimidazole [C16H12N2O2, (I)], 2-(furan-2-yl)-1-(furan-2-ylmethyl)-1H-benzimidazol-3-ium chloride monohydrate [C16H13N2O2(+)·Cl(-)·H2O, (II)] and the hydrobromide salt 5,6-dimethyl-2-(furan-2-yl)-1-(furan-2-ylmethyl)-1H-benzimidazol-3-ium bromide [C18H17N2O2(+)·Br(-), (III)] are described. Benzimidazole (I) displays two sets of aromatic interactions, each of which involves pairs of molecules in a head-to-tail arrangement. The first, denoted set (Ia), exhibits both intermolecular C-H···π interactions between the 2-(furan-2-yl) (abbreviated as Fn) and 1-(furan-2-ylmethyl) (abbreviated as MeFn) substituents, and π-π interactions involving the Fn substituents between inversion-center-related molecules. The second, denoted set (Ib), involves π-π interactions involving both the benzene ring (Bz) and the imidazole ring (Im) of benzimidazole. Hydrated salt (II) exhibits N-H···OH2···Cl hydrogen bonding that results in chains of molecules parallel to the a axis. There is also a head-to-head aromatic stacking of the protonated benzimidazole cations in which the Bz and Im rings of one molecule interact with the Im and Fn rings of adjacent molecules in the chain. Salt (III) displays N-H···Br hydrogen bonding and π-π interactions involving inversion-center-related benzimidazole rings in a head-to-tail arrangement. In all of the π-π interactions observed, the interacting moieties are shifted with respect to each other along the major molecular axis. Basis set superposition energy-corrected (counterpoise method) interaction energies were calculated for each interaction [DFT, M06-2X/6-31+G(d)] employing atomic coordinates obtained in the crystallographic analyses for heavy atoms and optimized H-atom coordinates. The calculated interaction energies are -43.0, -39.8, -48.5, and -55.0 kJ mol(-1) for (Ia), (Ib), (II), and (III), respectively. For (Ia), the analysis was used to partition the interaction energies into the C-H···π and π-π components, which are 9.4 and 24.1 kJ mol(-1), respectively. Energy-minimized structures were used to determine the optimal interplanar spacing, the slip distance along the major molecular axis, and the slip distance along the minor molecular axis for 2-(furan-2-yl)-1H-benzimidazole.

Poly[tris-(acetato-κ(2) O,O')(μ2-acetato-κ(3) O,O':O)tetra-kis-(μ3-acetato-κ(4) O,O':O:O')bis-(benzene-1,2-di-amine-κN)tetra-lead(II)], [Pb4(CH3COO)8(C6H8N2)2] n , (I), poly[(acetato-κ(2) O,O')(μ3-acetato-κ(4) O,O':O:O')(4-chloro-benzene-1,2-diamine-κN)lead(II)], [Pb(CH3COO)2(C6H7ClN2)] n , (II), and poly[(κ(2) O,O')(μ3-acetato-κ(4) O,O':O:O')(3,4-di-amino-benzo-nitrile-κN)lead(II)], [Pb(CH3COO)2(C7H7N3)] n , (III), have polymeric structures in which monomeric units are joined by bridging acetate ligands. All of the Pb(II) ions exhibit hemidirected coordination. The repeating unit in (I) is composed of four Pb(II) ions having O6, O6N, O7 and O6N coordination spheres, respectively, where N represents a monodentate benzene-1,2-di-amine ligand and O acetate O atoms. Chains along [010] are joined by bridging acetate ligands to form planes parallel to (10-1). (II) and (III) are isotypic and have one Pb(II) ion in the asymmetric unit that has an O6N coordination sphere. Pb2O2 units result from a symmetry-imposed inversion center. Polymeric chains parallel to [100] exhibit hydrogen bonding between the amine and acetate ligands. In (III), additional hydrogen bonds between cyano groups and non-coordinating amines join the chains by forming R 2 (2)(14) rings.

The structures of 4-nitrobenzene-1,2-diamine [C6H7N3O2, (I)], 2-amino-5-nitroanilinium chloride [C6H8N3O2(+)·Cl(-), (II)] and 2-amino-5-nitroanilinium bromide monohydrate [C6H8N3O2(+)·Br(-)·H2O, (III)] are reported and their hydrogen-bonded structures described. The amine group para to the nitro group in (I) adopts an approximately planar geometry, whereas the meta amine group is decidedly pyramidal. In the hydrogen halide salts (II) and (III), the amine group meta to the nitro group is protonated. Compound (I) displays a pleated-sheet hydrogen-bonded two-dimensional structure with R2(2)(14) and R4(4)(20) rings. The sheets are joined by additional hydrogen bonds, resulting in a three-dimensional extended structure. Hydrohalide salt (II) has two formula units in the asymmetric unit that are related by a pseudo-inversion center. The dominant hydrogen-bonding interactions involve the chloride ion and result in R4(2)(8) rings linked to form a ladder-chain structure. The chains are joined by N-H···Cl and N-H···O hydrogen bonds to form sheets parallel to (010). In hydrated hydrohalide salt (III), bromide ions are hydrogen bonded to amine and ammonium groups to form R4(2)(8) rings. The water behaves as a double donor/single acceptor and, along with the bromide anions, forms hydrogen bonds involving the nitro, amine, and ammonium groups. The result is sheets parallel to (001) composed of alternating R5(5)(15) and R6(4)(24) rings. Ammonium N-H···Br interactions join the sheets to form a three-dimensional extended structure. Energy-minimized structures obtained using DFT and MP2 calculations are consistent with the solid-state structures. Consistent with (II) and (III), calculations show that protonation of the amine group meta to the nitro group results in a structure that is about 1.5 kJ mol(-1) more stable than that obtained by protonation of the para-amine group. DFT calculations on single molecules and hydrogen-bonded pairs of molecules based on structural results obtained for (I) and for 3-nitrobenzene-1,2-diamine, (IV) [Betz & Gerber (2011). Acta Cryst. E67, o1359] were used to estimate the strength of the N-H···O(nitro) interactions for three observed motifs. The hydrogen-bonding interaction between the pairs of molecules examined was found to correspond to 20-30 kJ mol(-1).

The title compound, {[Zn2(CH3CO2)3(OH)(C6H7ClN2)]·C2H5OH} n , has alternating octa-hedrally and tetra-hedrally coordinated Zn(2+) ions. The octa-hedral coordination sphere is composed of one N atom of the monodentate di-amino-chloro-benzene ligand, three acetate O atoms and two bridging hydroxide ligands. The tetra-hedral coordination sphere consists of three acetate O atoms and the hydroxide ligand. The zinc ions are bridged by acetate and hydroxide ligands. The result is a laddered-chain structure parallel to [100] with ethanol solvent mol-ecules occupying the space between the chains. The di-amine ligand chlorine substitutent is disordered over two equally populated positions as a result of a crystallographically imposed inversion center between adjacent ligands. The ethanol solvent mol-ecule exhibits disorder with the two components having refined occupancies of 0.696 (11) and 0.304 (11). O-H⋯O hydrogen bonds form between the hydroxide ligand and the ethanol solvent mol-ecule. N-H⋯O and N-H⋯N hydrogen bonding between the uncoordinated amine group and the acetate ligands and the coordinated amine group are also observed.

The title mol-ecule, C20H20N2S2, is T-shaped and consists of a nearly flat 5,6-dimethyl-2-(5-methyl-thio-phen-2-yl)benzimidazole system approximately perpendicular to the 5-methyl-thio-phen-2-ylmethyl substituent. The 5,6-dimethyl-2-(5-meth-yl-thio-phen-2-yl)benzimidazole system is rotationally disordered about the two imidazole N atoms as approximated by a twofold rotation axis with a refined major/minor occupancy ratio of 0.884 (2):0.116 (2). The benzimidazole ring system is essentially planar, the largest deviations being 0.026 (2) and 0.044 (18) Å in the major and minor components, respectively. The inter-planar angles between the benzimidazole unit and the 5-methyl-thio-phen-2-yl substituent are 10.8 (3) and 8(3)° in the major and minor components, respectively, and the corresponding angles with the 5-methyl-thio-phen-2-ylmethyl substituent are 88.12 (8) and 89.5 (4)°. In the crystal, mol-ecules are oriented with their 2-(5-methyl-thio-phen-2-yl)benzimidazole mean planes approximately parallel to (11[Formula: see text]) and appear to be held together by π-π [2-thiophene⋯imidazole centroid-centroid distance = 4.1383 (7) Å] and C-H⋯π contacts. A weak C-H⋯N hydrogen bond generates infinite chains parallel to [100].

The title compound, C18H13Br3N2S2, was obtained via the reaction of N-bromo-succinamide with 5,6-dimethyl-2-(thio-phen-2-yl)-1-[(thio-phen-2-yl)meth-yl]-1H-benzimidazole. The compound exhibits rotational disorder of the 5-bromo-thio-phen-2-yl substituent with a refined major:minor occupancy ratio of 0.876 (7):0.124 (7). The 5-bromo-thio-phen-2-yl mean plane is canted to the benzimidazole plane by 20.0 (4) and 21 (4)° in the major and minor components, respectively. In the crystal, weak C-H⋯N inter-actions link the mol-ecules into infinite C(7) chains along the 21 axes.

The title compound, C20H18N4, was obtained via the condensation of 4,5-di-methyl-benzene-1,2-di-amine with pyridine-2-carbaldehyde. The plane of the 2-(pyridin-2-yl) substitutent is canted by 2.75 (11)° from the plane of the benzimidazole system. The mol-ecule exhibits an S(6) C-H⋯N intra-molecular hydrogen-bond motif. In the crystal, C-H⋯N hydrogen bonds link pairs of mol-ecules related by a crystallographic inversion center, forming R 2 (2)(20) rings. Additional weak C-H⋯N hydrogen bonds result in C(9) chains parallel to [001].

There are two independent mol-ecules in the asymmetric unit of the title compound, C16H11ClN2S2. The structure exhibits rotational disorder of the 2-thio-phen-2-yl substituent in each of the unique mol-ecules with a major:minor component ratio of 0.927 (2):0.073 (2). For one of the symmetry-unique molecules, 6.0 (2)% of the sites are occupied by the 6-chloro-isomer. The major component thio-phene rings make dihedral angles of 38.90 (12) and 36.32 (11)° with the benzimidazole rings in the two independent mol-ecules. In the crystal, mol-ecules are linked into chains parallel to [100] via weak C-H⋯N inter-actions.

The asymmetric unit of the title compound, C10H8N2S2, is composed of two independent half-mol-ecules, each residing on a center of symmetry. In the crystal, weak C-H⋯π inter-actions join the two symmetry-independent molecules together into interlinked chains parallel to [011]. The crystal structure was refined as a two-component pseudo-merohedral twin using the twin law 001 0-10 100. The refined domain fractions are 0.516 (3) and 0.484 (3).

The title compound, C16H11ClN2S2, co-crystallizes with a small amount of the 5-chloro- isomer. The ratio of 6-chloro- to 5-chloro- isomers is 0.969 (2):0.031 (2). One thio-phen-2-yl substitutent displays rotational disorder with 80.6 (4)% of the mol-ecules exhibiting the major orientation. In the crystal, weak C-H⋯N and C-H⋯S hydrogen-bonding inter-actions result in chains of mol-ecules parallel to [001].

The title compound, C7H7N3, is an ortho-rhom-bic polymorph that crystallizes in the space group Pca21. The previously reported monoclinic form [Geiger & Parsons (2013 ▶) Acta Cryst. E69, o452] crystallizes in the space group P21/c (Z = 4). In the crystal, two independent HN-H⋯N C hydrogen bonds link the mol-ecules into chains along the a-glide plane. Two further independent HN-H⋯NH2 hydrogen bonds join the chains, forming a three-dimensional network.

The non-H atoms in the structure of the title mol-ecule, C7H7N3, are almost coplanar (r.m.s. deviation = 0.018 Å). The two amine groups each donate two and accept one weak N-H⋯N hydrogen bonds. N-H⋯N hydrogen bonding between the amine and nitrile groups results in chains parallel to [101] in the crystal structure. The chains are cross-linked by N-H⋯N hydrogen bonds between amine groups, giving rise to an infinite three-dimensional network.

There are two independent mol-ecules in the asymmetric unit of the title compound, C(16)H(11)BrN(2)S(2). In the crystal, weak C-H⋯N hydrogen bonds and C-H⋯thio-phene ring inter-actions link the mol-ecules into chains along [100]. The structure exhibits disorder of the 2-thio-phen-2-yl substituent of one of the symmetry-unique mol-ecules with a major:minor component ratio of 0.914 (3):0.086 (3).

In the title mol-ecule, C(11)H(9)N(3)O(2)S, the thio-phene and benzene rings form a dihedral angle of 17.68 (9)°. The thio-phene S atom and the imine N atom are syn with respect to each other. In the crystal, N-H⋯O and N-H⋯N hydrogen bonds connect mol-ecules, forming a two-dimensional network parallel to (10-1).

The title hydrated salt, C(21)H(17)N(2)O(3) (+)·Cl(-)·H(2)O, exhibits disorder in one of the furan rings. The major and minor components have a refined occupancy ratio of 0.844 (19):0.156 (19). The structure displays intermolecular hydrogen bonding involving the water molecule and the chloride anion. Close intermolecular C-H⋯Cl and C-H⋯(furan ring) inter-actions complete the hydrogen bonding.

The structure of the title compound, [Zn(CH(3)COO)(2)(C(8)H(12)N(2))(2)], has one half molecule in the asymmetric unit. The Zn(II) atom is situated on a twofold rotation axis and is tetrahedrally coordinated by two N and two O atoms. The crystal packing displays inter-molecular N-H⋯O hydrogen bonds and intra-molecular N-H⋯O and N-H⋯N hydrogen bonding.

In the title compound, C(16)H(12)N(2)S(2), the thio-phene groups are rotationally disordered over two sets of sites, by approximately 180°, with occupancy ratios of 0.916 (2):0.084 (2) and 0.903 (2):0.097 (2). The major components of the thio-phene and methyl-ene substituted thio-phene rings are canted by 24.06 (12) and 85.07 (10)°, respectively, from the benzimidazole ring system plane and the dihedral angle between the major component thio-phene ring planes is 84.90 (14)°. In the crystal, there is a weak C-H⋯N hydrogen bond which links mol-ecules into chains.

Nocturnal melatonin secretion is concurrent with consolidated sleep episodes in diurnal mammals and physiological melatonin levels can promote sleep onset in humans and in pigtail macaques. In order to further investigate the effects of melatonin treatment on sleep parameters in diurnal nonhuman primates, three macaque species have been studied: Macaca nemestrina, Macaca fascicularis, and Macaca mulatta. Sleep was assessed using continuous actigraphic recording of motor activity in animals maintained under 12:12-h light/dark cycle. Oral doses of melatonin (5-320 microg/kg) were administered 2 h before lights-off time, with 5- and 10-microg/kg doses resulting in physiological circulating melatonin levels (31-95 pg/ml). The effects of melatonin administration were similar in three species studied and included significantly earlier sleep onset time and longer sleep period time, with no difference in time of awakening, following administration of both physiological (5-10 microg/kg) and pharmacological (20-320 microg/kg) doses. While low melatonin doses (5-20 microg/kg) did not significantly affect nighttime sleep efficiency, higher pharmacological doses reduced sleep efficiency and increased sleep fragmentation at night, and reduced spontaneous daytime locomotor activity. Daily administration of a 5-microg/kg dose for 4 weeks or gradually escalating melatonin doses (5-320 microg/kg over a 3-week period) did not result in the development of tolerance or sensitization to the effect of melatonin on sleep initiation or sleep period. These data affirm that sleep-promoting effects of melatonin observed in humans are also typical for diurnal primates. They also suggest that physiological and pharmacological melatonin levels might produce different effects on sleep efficiency and that nonhuman primates can serve as adequate animal model for studying the mechanisms of melatonin's action on sleep and performance.