Crystal structure of bis-[2-(1H-benzimid-azol-2-yl)-4-bromo-phenolato-κ(2) N (3),O]cobalt(II).

The asymmetric unit of the title Co(II) complex, [Co(C13H8BrN2O)2], contains two independent mol-ecules (A and B). In both mol-ecules, the Co(II) cation is N,O-chelated by two 2-(1H-benzimidazol-2-yl)-4-bromo-phenolate anions in a distorted tetra-hedral geometry. In mol-ecule A, both chelating rings display an envelope conformation, with the flap Co atom lying 0.614 (6) and 0.483 (6) Šfrom the mean planes of the remaining atoms. In mol-ecule B, both chelating rings are approximately planar, the maximum deviations being 0.039 (4) and 0.076 (3) Å. In the crystal, mol-ecules are linked by classical N-H⋯O hydrogen bonds and weak C-H⋯O and C-H⋯Br hydrogen bonds into a three-dimensional supra-molecular network. Extensive π-π stacking is observed between nearly parallel aromatic rings of adjacent mol-ecules with centroid-centroid distances in the range 3.407 (3)-3.850 (4) Å.

1-(4-Bromo-benz-yl)-2-(4-bromo-phen-yl)-1H-benzimidazole.

There are two mol-ecules in the asymmetric unit of the title compound, C20H14Br2N2. In the first, the dihedral angles between the mean plane of the benzimidazole group and those of the 4-bromo-benzyl and 4-chloro-phenyl groups are 50.72 (17) and 71.29 (16)°, respectively, while the corresponding angles in the second mol-ecule are 42.09 (16) and 89.05 (17)°. The 4-bromo-benzyl and 4-bromo-phenyl groups make an angle of 68.1 (2) and 85.1 (21)° with each other in the two mol-ecules. In the crystal, weak C-H⋯N and C-H⋯Br hydrogen bonds link the mol-ecules along the c-axis direction. Br⋯Br inter-actions [3.5733 (9)Å] are also observed.

Bis(adamantan-1-aminium) tetrachloridozincate(II) 18-crown-6 monohydrate clathrate.

The structure of the title compound [systematic name: bis(adamantan-1-aminium) tetrachloridozincate(II)-1,4,7,10,13,16-hexaoxacyclooctadecane-water (1/1/1)], (C(10)H(18)N)(2)[ZnCl(4)] x C(12)H(24)O(6) x H(2)O, consists of supramolecular rotator-stator assemblies and ribbons of hydrogen bonds parallel to [010]. The assemblies are composed of one protonated adamantan-1-aminium cation and one crown ether molecule (1,4,7,10,13,16-hexaoxacyclooctadecane) to give an overall [(C(10)H(18)N)(18-crown-6)](+) cation. The -NH(3)(+) group of the cation nests in the crown and links to the crown-ether O atoms through N-H...O hydrogen bonds. The 18-crown-6 ring adopts a pseudo-C(3v) conformation. The second adamantan-1-aminium forms part of ribbons of adamantan-1-aminium-water-tetrachloridozincate units which are interconnected by O-H...Cl, N-H...O and N-H...Cl hydrogen bonds via three different continuous rings with R(5)(4)(12), R(4)(3)(10) and R(3)(3)(8) motifs.

Propane-1,3-diaminium tetrachloridozincate(II) 18-crown-6 clathrate.

The reaction of propane-1,3-diamine hydrochloride, 18-crown-6 and zinc(II) chloride in methanol solution yields the title complex salt [systematic name: propane-1,3-diaminium tetrachloridozincate(II)-1,4,7,10,13,16-hexaoxacyclooctadecane (1/1)], (C(3)H(12)N(2))[ZnCl(4)] x C(12)H(24)O(6), with an unusual supramolecular structure. The diprotonated propane-1,3-diaminium cation forms an unexpected 1:1 supramolecular rotator-stator complex with the crown ether, viz. [C(3)H(12)N(2)(18-crown-6)](2+), in which one of the -NH(3)(+) substituents nests in the crown and interacts through N-H...O hydrogen bonding. The other -NH(3)(+) group interacts with the [ZnCl(4)](2-) anion via N-H...Cl hydrogen bonding, forming cation-crown-anion ribbons parallel to [010].

5-p-Tolyl-1H-tetra-zole.

The title compound, C(8)H(8)N(4), possesses crystallographic mirror symmetry, with four C atoms lying on the reflecting plane, which bis-ects the phenyl and tetra-zole rings. It is composed of a planar r.m.s. deviation (0.0012 Å) tetra-zole ring which is nearly coplanar with the benzene ring, the dihedral angle being 2.67 (9)°. In the crystal, symmetry-related mol-ecules are linked by inter-molecular N-H⋯N hydrogen bonds. The mol-ecules stack along [100] with a π⋯π inter-action involving the phenyl and tetra-zole rings of adjacent mol-ecules [centroid-centroid distance = 3.5639 (15) Å]. The H atom of the N-H group is disordered over two sites of equal occupancy. The methyl H atoms were modelled as disordered over two sets of sites of equal occupancy rotated by 60° with respect to each other.

2-Carb-oxy-1-phenyl-ethanaminium nitrate.

In the title salt, C(9)H(12)NO(2) (+)·NO(3) (-), the cation and anion are linked by a bifurcated N-H⋯(O,O) hydrogen bond. The crystal packing is stabilized by inter-molecular N-H⋯O, O-H⋯O and C-H⋯O hydrogen bonds, which connect neighbouring cations and anions, resulting in a two-dimensional network.

2-Carb-oxy-1-(3-nitro-phen-yl)ethanaminium perchlorate.

In the cation of the title compound, C(9)H(11)N(2)O(4) (+)·ClO(4) (-), the conformation is stabilized by an intra-molecular N-H⋯O hydrogen bond. In the crystal packing, centrosymmetrically related cations inter-act through inter-molecular O-H⋯O hydrogen bonds involving the carb-oxy groups, forming dimers. The dimers and the perchlorate anions are further linked into layers parallel to the ab plane by C-H⋯O and N-H⋯O hydrogen-bonding inter-actions.

Dimethyl 1-cyano-methyl-1H-pyrazole-3,5-dicarboxyl-ate.

The title mol-ecule, C(9)H(9)N(3)O(4), syhthesized from 1H-pyrazole-3,5-dicarboxylic acid and 2-bromo-acetonitrile, is approximately planar; the inter-planar angles between the pyrazole ring and the mean planes of the two carboxylate units and the cyanomethyl unit are 4.49 (10), 5.56 (9) and 5.03 (19)°, respectively. In the crystal, inversion dimers linked by pairs of weak C-H ⋯O bonds occur, and the packing is further stabilized by aromatic π-π stacking [centroid-centroid separation = 3.793 (4) Å].

2-Carb-oxy-1-phenyl-ethanaminium perchlorate.

In the title compound, C(9)H(12)NO(2) (+)·ClO(4) (-), an intra-molecular N-H⋯O inter-action results in the formation of a six-membered ring having a twisted chair conformation. In the crystal structure, inter-molecular O-H⋯O, N-H⋯O and C-H⋯O inter-actions link the mol-ecules into a network. A weak C-H⋯π inter-action is also found.

3-(2-Pyrid-yl)-5-(4-pyrid-yl)-4-(p-tol-yl)-1H-1,2,4-triazole.

In the mol-ecule of the title compound, C(19)H(15)N(5), the dihedral angles formed by the plane of the triazole ring with those of the 2-pyridyl, 4-pyridyl and p-tolyl rings are 28.12 (10), 34.62 (10) and 71.43 (9)°, respectively. The crystal structure is consolidated by C-H⋯π hydrogen-bonding inter-actions and by π-π stacking inter-actions, with a centroid-centroid distance of 3.794 (4) Å.

Oxonium 2-carb-oxy-3-(2-fur-yl)acrylate.

In the title compound, H(3)O(+)·C(8)H(5)O(5) (-), neighbouring cations and anions are linked by O-H⋯O hydrogen bonds, forming a one-dimensional chain framework along [001]. The crystal structure is further stabilized by π-π inter-actions, with centroid-centroid distances of 3.734 (3) Å.

Redetermination of 3-(ammonio-meth-yl)pyridinium dichloride.

The crystal structure of the title compound, C(6)H(10)N(2) (2+)·2Cl(-), has been reported previously in the non-standard setting P2(1)/a [Genet (1965 ▶). Bull. Soc. Fr. Miner. Crist.88, 463-470], with an R value of 0.16. The current redetermination improves significantly the precision of the geometric parameters. In the crystal packing, cations and anions are linked by inter-molecular N-H⋯Cl and C-H⋯Cl hydrogen bonds into a three-dimensional network.

2-(Chloro-meth-yl)benzimidazolium chloride.

The structure of title compound, C(8)H(8)ClN(2) (+)·Cl(-), comprises discrete ions which are inter-connected by N-H⋯Cl hydrogen bonds, leading to a neutral one-dimensional network in [001]. This hydrogen bonding appears to complement π-π stacking inter-actions [centroid-centroid distances 3.768 (2) and 3.551 (2) Å] and helps to stabilize the structure further.

Does the surface matter? Hydrogen-bonded chain formation of an oxalic amide derivative in a two- and three-dimensional environment.

We report on a multi-technique investigation of the supramolecular organisation of N,N-diphenyl oxalic amide under differently dimensioned environments, namely three-dimensional (3D) in the bulk crystal, and in two dimensions on the Ag(111) surface as well as on the reconstructed Au(111) surface. With the help of X-ray structure analysis and scanning tunneling microscopy (STM) we find that the molecules organize in hydrogen-bonded chains with the bonding motif qualitatively changed by the surface confinement. In two dimensions, the chains exhibit enantiomorphic order even though they consist of a racemic mixture of chiral entities. By a combination of the STM data with near-edge X-ray absorption fine-structure spectroscopy, we show that the conformation of the molecule adapts such that the local registry of the functional group with the substrate is optimized while avoiding steric hindrance of the phenyl groups. In the low coverage case, the length of the chains is limited by the Au(111) reconstruction lines restricting the molecules into fcc stacked areas. A kinetic Monte Carlo simulated annealing is used to explain the selective assembly in the fcc stacked regions.

Homochiral laminar europium metal-organic framework with unprecedented giant dielectric anisotropy.

Hydrothermal (deuteratothermal) reaction of L-ethyl lactate (Lig-Et) with Eu(ClO(4))(3)6 H(2)O gives colorless block crystals of [Eu(Lig)(2)(X(2)O)(2)][ClO(4)] (1, X=H; 2, X=D) both of which possess a two-dimensional laminar homochiral framework. Single-crystal dielectric measurements reveal that 1 and 2 display a giant dielectric anisotropy approximately exceeding 100 and large isotopic effect with about 54 % enhancement along the a axis. Their ferroelectric features further confirm this respect. Crystal parameters: 1, C(6)H(14)ClO(12)Eu, M(r)=465.58, monoclinic, C(2), a=8.6786(6), b=8.3965(6), c=10.2153(7) A, beta=92.040(1) degrees , V=743.92(9) A(3), Z=2, rho(calcd)=2.079 Mg m(-3), R(1)=0.0508, wR(2)=0.1239, mu=4.448 mm(-1), S=1.043; Flack=0.04(5). 2: C(6)H(10)D(4)ClO(12)Eu, M(r)=469.61, monoclinic, C(2), a=8.689(2), b=8.410(2), c=10.224(3) A, beta=92.057(4) degrees , V=746.7(3) A(3), Z=2, rho(calcd)=2.089 Mg m(-3), R(1)=0.0465, wR(2)=0.1150, mu=4.432 mm(-1), S=1.058; Flack=0.02(5).

In situ hydrothermal synthesis of tetrazole coordination polymers with interesting physical properties.

Tetrazole compounds have been studied for more than one hundred years and applied in various areas. Several years ago Sharpless and his co-workers reported an environmentally friendly process for the preparation of 5-substituted 1H-tetrazoles in water with zinc salt as catalysts. To reveal the exact role of the zinc salt in this reaction, a series of hydrothermal reactions aimed at trapping and characterizing the solid intermediates were investigated. This study allowed us to obtain a myriad interesting metal-organic coordination polymers that not only partially showed the role of the metal species in the synthesis of tetrazole compounds but also provided a class of complexes displaying interesting chemical and physical properties such as second harmonic generation (SHG), fluorescence, ferroelectric and dielectric behaviors. In this tutorial review, we will mainly focus on tetrazole coordination compounds synthesized by in situ hydrothermal methods. First, we will discuss the synthesis and crystal structures of these compounds. Their various properties will be mentioned and we will show the applications of tetrazole coordination compounds in organic synthesis. Finally, we will outline some expectations in this area of chemistry. The direct coordination chemistry of tetrazoles to metal ions and in situ synthesis of tetrazole through cycloaddition between organotin azide and organic cyano group will be not discussed in this review.

catena-Poly[cadmium(II)-µ-benzene-1,2-diamine-κN:N'-di-µ-chlorido].

The title compound, [CdCl(2)(C(6)H(8)N(2))](n), is a coordination polymer prepared by the hydro-thermal reaction of cadmium chloride and o-diamino-benzene. The cadmium cation, located on an inversion center, is octa-hedrally coordinated by four Cl atoms at equatorial sites and two N atoms from two ligands at the axial sites. Cd atoms are bridged by Cl atoms, forming extended chains parallel to [010]. Neighboring chains are connected by N-H⋯Cl hydrogen bonds.

4-[(2H-Tetra-zol-2-yl)meth-yl]benzonitrile.

The title compound, C(9)H(7)N(5), was synthesized by reaction of 4-(bromomethyl)benzonitrile and 2H-tetrazole in the presence of KOH. The relative orientation of the planar tetra-zole ring and the methyl-benzonitrile moiety is (-)-anti-clinal. The crystal packing is dominated by van der Waals inter-actions.

(2Z,2'Z,4E,4'E)-4,4'-(Cyclo-hexane-1,2-diyldinitrilo)dipent-2-en-2-ol.

A new tetra-dentate chiral Schiff base ligand, C(16)H(26)N(2)O(2), has been synthesized by the reaction of acetyl-acetone with (1R,2R)-(-)-1,2-diamino-cyclo-hexane. Both of the mol-ecules in the asymmetric unit are of the same chirality (R configuration), since the absolute configuration was determined by the starting reagent (1R,2R)-(-)-1,2-diamino-cyclo-hexane. The six-membered cyclo-hexane ring is in a chair conformation, and the substituents are equatorial in the most stable conformation (trans-cyclo-hexyl). At the ring substituents, large conjugated -C=N-CH=C-OH systems exist, resulting from the original ketone converted into the enol form. With H atoms excluded, the atoms of each substituent lie in the same plane. The two mol-ecules in the asymmetric unit have almost the same structure, with slight differences in the torsion angles between the substituents and the cyclo-hexane ring; the corresponding N(1)-(C-C-C)(cyclo-hexa-ne) torsion angles are -177.2 (3) and 179.3 (4)° in one mol-ecule and -176.5 (3) and 178.4 (4)° in the other. Two intra-molecular O-H⋯N hydrogen bonds exist in each mol-ecule.