dl-Asparaginium nitrate

In the title compound, C4H9N2O3 +·NO3 −, alternatively called (1RS)-2-carbamoyl-1-carboxy­ethanaminium nitrate, the asymmetric unit comprises one asparaginium cation and one nitrate anion. The strongest cation–cation O—H⋯O hydrogen bond in the structure, together with other strong cation–cation N—H⋯O hydrogen bonds, generates a succession of infinite chains of R 2 2(8) rings along the b axis. Additional cation–cation C—H⋯O hydrogen bonds link these chains into two-dimensional layers formed by alternating R 4 4(24) and R 4 2(12) rings. Connections between these layers are provided by the strong cation–anion N—H⋯O hydrogen bonds, as well as by one weak C—H⋯O inter­action, thus forming a three-dimensional network. Some of the cation–anion N—H⋯O hydrogen bonds are bifurcated of the type D—H⋯(A 1,A 2)

On the accurate estimation of intermolecular interactions and charge transfer: the case of TTF-CA

International audienceHigh-resolution X-ray diffraction experiments and state-of-the-art density functional theory calculations have been performed. The validity of the atoms-in-molecules approach is tested for the neutral-ionic transition of TTF-CA which involves a transfer of less than one electron between the donor and acceptor molecules. Foremost, crystallographical data have been reassessed along the temperature-induced neutral-ionic phase transition undergone by this charge transfer complex. Based on accurate X-ray structures at 105 and 15 K, topological analysis of both DFT and the experimental multipolar electron densities allowed detailed characterization of intra- and interstack intermolecular interactions. Direct quanti. cation of the intermolecular charge transfer and the dipole moment are discussed

Adeninium cytosinium sulfate

In the title compound, C5H6N5 +·C4H6N3O+·SO4 2−, the adeninium (AdH+) and cytosinium (CytH+) cations and sulfate dianion are involved in a three-dimensional hydrogen-bonding network with four different modes, viz. AdH+⋯AdH+, AdH+⋯CytH+, AdH+⋯SO4 2− and CytH+⋯SO4 2−. The adeninium cations form N—H⋯N dimers through the Hoogsteen faces, generating a characteristic R 2 2(10) motif. This AdH+⋯AdH+ hydrogen bond in combination with AdH+⋯CytH+ H-bonds leads to two-dimensional cationic ribbons parallel to the a axis. The sulfate anions inter­link the ribbons into a three-dimensional hydrogen-bonding network and thus reinforce the crystal structure

dl-Asparaginium perchlorate

Two enantiomeric counterparts (l- and d-asparginium cations related by glide planes) are present in the structure of the title compound, C4H9N2O3 +·ClO4 −, with a 1:1 cation–anion ratio. The structure is built up from asparginium cations and perchlorate anions. In the crystal, mol­ecules assemble in double layers parallel to (100) through N—H⋯O, O—H⋯O and C—H⋯O hydrogen bonds. In the asparginium layers, hydrogen bonds generate alternating R 2 2(8) and R 4 3(18) graph-set motifs. Further hydrogen bonds involving the anions and cations result in the formation of a three-dimensional network

Adeninium 3-carboxy­anilinium bis­(perchlorate) trihydrate

In the title salt, C5H6N5 +·C7H8NO2 +·2ClO4 −·3H2O, the 3-carboxy­anilinium and adeninium cations are monoprotonated at the amino group and at a pyrimidine N atom respectively. In the crystal, the components are involved in extensive three-dimensional hydrogen-bonding networks composed of O—H⋯O, N—H⋯O, O—H⋯N, N—H⋯N and C—H⋯O inter­actions. Bifurcated hydrogen bonds are observed between perchlorate O atoms and adeninium cations

trans-Di-μ-iodido-bis­[(3H-1,2-benzodithiole-3-thione)iodidomercury(II)]

The complete molecule of the dinuclear title compound, [Hg2I4(C7H4S3)2], is generated by crystallographic inversion symmetry. The complex has a dimeric structure in which each HgII ion adopts a tetra­hedral geometry and is coordinated by two bridging I atoms, one terminal iodide ion and one thio­carbonyl S atom (C=S) of the ligand. The square plane formed by the Hg and I atoms and their symmetry counterparts makes a dihedral angle of 89.66 (3)° with the DDT plane. There is no classical hydrogen bonding, but weak S⋯S inter­actions of 3.4452 (7) and 3.6859 (7) Å maintain the cohesion of the crystal structure

4-{2-[3-(2-Ammonioacetamido)propanamido]ethyl}-1H-imidazol-3-ium dichloride

Mol­ecules of the title compound, Gly-β-Ala-Histamine dihydro­chloride, C10H19N5O2 2+·2Cl−, are linked by N—H⋯O and N—H⋯Cl hydrogen bonds into two-dimensional polymeric sheets parallel to the (011) plane, forming a stacked structure along the a axis. The parallel layers are also inter­linked alternately by different N—H⋯Cl hydrogen bonds, forming a three-dimensional framework

Inter-layer charge disproportionation in the dual-layer organic metal (tTTF-I)2ClO4 with unsymmetrical I***O halogen bond interactions.

Accepted 19 Nov 2013International audienceA mixed-valence salt of tTTF-I with ClO4(-), formulated as (tTTF-I)2ClO4, is characterized by the presence of two crystallographically independent donor molecules, segregated in different layers and linked together through I***O interactions with the ClO4(-) anion disordered at room temperature. The tTTF-I donor molecule was prepared by metallation of tTTF (trimethylene tetrathiafulvalene) followed by reaction with iodine to afford the mono and diiodo derivatives tTTF-I and tTTFI2, respectively. The crystal structure of the latter neutral tTTFI2 shows the occurrence of strong type II, II halogen bond interactions. Band structure calculations of the dual-layer structure of the 2 : 1 salt (tTTF-I)2ClO4 show co-existence of both 1D open and 2D closed Fermi surfaces. The salt undergoes a metal-insulator phase transition at T(MI) = 90 K, associated with an electronic dimensionality decrease, since already at 100 K, the 2D part of the Fermi surface transforms into 1D corrugated planes. High resolution X-ray investigations performed at 100 K, combined with multipolar refinements, indicate an approximately equivalent +0.5e charge in both donor molecules, as also deduced from the intramolecular bond distances. On the other hand, Raman spectroscopic investigations show that at ambient temperature the charge is actually distributed non-uniformly in conducting layers of tTTF-I molecules, with the identification of molecules with charges +1, +0.5, 0e, while at low temperature the charge distribution becomes essentially uniform (+0.5e), as confirmed from the X-ray high resolution data. These apparently contradictory behaviors are actually a consequence of a partial electron transfer between the two independent slabs to reach a common Fermi level in the metallic phase

Intra- and supra­molecular inter­actions in cis,mer-diaqua­tris­(1H-imidazole-κN 3)(terephthalato-κO)cobalt(II) monohydrate

In the title compound, [Co(C8H4O4)(C3H4N2)3(H2O)2]·H2O, the cisoid angles are in the range 85.59 (5)–93.56 (5)°, while two equal transoid angles deviate significantly from the ideal linear angle, the third being almost linear. One carboxyl­ate group is almost coplanar [1.23 (13)°] with the plane of its parent aromatic ring, although it has one O-atom donor involved in one coordination and one hydrogen bond as acceptor. The other carboxyl­ate group does not coordinate and is rotated out of this plane with a torsional twist of 17.27 (20)°. The coordination neutral entity, based on aqua ligands and two cyclic co-ligands seems, at first sight, monomeric. Strongly tight, via one intra­molecular hydrogen bond between aqua and carboxyl­ate O atoms, it brings out a quasi-planar six-membered ring around the CoII atom, turning the CoN3O3 coordination octa­hedron into a new building block. The rigidity of this feature associated with several hydrogen-bonded arrays yields an extended structure. In the resulting supra­molecular packing, a binuclear hydrated CoII assembly, built up from triple strands driven by different heterosynthons, embodies the synergy of coordination, covalent and hydrogen bonds

N-[4-Acetyl-5-(2-methylprop-1-enyl)-5-(2-p-tolyl­prop­yl)-4,5-dihydro-1,3,4-thia­diazol-2-yl]acetamide

The title heterocyclic compound, C20H27N3O2S, was synthesized from 2-(4-methyl­cyclo­hex-3-en­yl)-6-methyl­hepta-2,5-dien-4-one, which was isolated from the essential oil Cedrus atlantica. The thia­diazole ring is essentially planar [maximum deviation 0.006 (2) Å] and it forms a dihedral angle of 18.08 (9)° with the benzene ring. The dihedral angle between the thia­diazole ring and the acetamide plane is 7.62 (10)°. In the crystal, mol­ecules are linked into chains running along the c axis by inter­molecular N—H⋯O hydrogen bonds