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

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 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 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)

3-Carboxyanilinium hemioxalate

In the title compound, C7H8NO2+·0.5C2O42−, the asymmetric unit consists of an 3-carboxyanilinium cation, and one-half of an oxalate anion, which lies on a twofold rotation axis. The crystal packing is consolidated by intermolecular N—H...O and O—H...O hydrogen bonds. The structure is built from infinite chains of cations and oxalate anions extending parallel to the b and c axes. The crystal studied was a non-merohedral twin. The ratio of the twin components refined to 0.335 (3):0.665 (3)

Crystal structure and Hirshfeld surface analysis of a new benzimidazole compound, 3-{1-[(2-hydroxyphenyl)methyl]-1H-1,3-benzodiazol-2-yl}phenol

The title compound, C20H16N2O2, is composed of two monosubstituted benzene rings and one benzimidazole unit. The benzimidazole moiety subtends dihedral angles of 46.16 (7) and 77.45 (8)° with the benzene rings, which themselves form a dihedral angle of 54.34 (9)°. The crystal structure features O—H...N and O—H...O hydrogen-bonding interactions, which together lead to the formation of two-dimensional hydrogen-bonded layers parallel to the (101) plane. In addition, π–π interactions also contribute to the crystal cohesion. Hirshfeld surface analysis indicates that the most significant contacts in the crystal packing are: H...H (47.5%), O...H/H...O (12.4%), N...H/H...N (6.1%), C...H/H...C (27.6%) and C...C (4.6%)

Syntheses and crystal structures of two magnesium-tetrazole compounds in salt and polymeric forms

International audienceTwo alkaline earth-tetrazole compounds, namely catena-poly[[[triaquamagnesium(II)]―5,5-(azanediyl)ditetrazolato- N-3(1),N-1:N-5] hemi\bis[-5,5-(azanediyl)ditetrazolato-N-3(1),N-1:N-2]bis[triaquama gnesium(II)]\ monohydrate], \[Mg(C2HN9)(H2O)(3)][Mg-2(C2HN9)(2)(H2O)(6)](0.5)H2O\(n), (I), and bis[5-(pyrazin-2-yl)tetrazolate] hexaaquamagnesium(II), (C5H3N6)[Mg(H2O)(6)], (II), have been prepared under hydrothermal conditions. Compound (I) is a mixed dimer-polymer based on magnesium ion centres and can be regarded as the first example of a magnesium-tetrazolate polymer in the crystalline form. The structure shows a complex three-dimensional hydrogen-bonded network that involves magnesium-tetrazolate dimers, solvent water molecules and one-dimensional magnesium-tetrazolate polymeric chains. The intrinsic cohesion in the polymer chains is ensured by NH...N hydrogen bonds, which form R-2(2)(7) rings, thus reinforcing the propagation of the polymer chain along the a axis. The crystal structure of magnesium tetrazole salt (II) reveals a mixed ribbon of hydrogen-bonded rings, of types R-2(2)(7), R-2(2)(9) and R-2(4)(10), running along the c axis, which are linked by R-2(4)(16) rings, generating a 4,8-c flu net

Diaquabis[5-(2-pyrazin-2-yl)tetrazolato]copper(II)–pyrazine-2-carbonitrile (1/2)

The title compound, [Cu(C5H3N6)2(H2O)2]·2C5H3N3, is a 1:2 co-crystal between the mononuclear complex diaquabis[5-(pyrazin-2-yl)tetrazolato]copper(II) and the reagent pyrazine-2-carbonitrile which was used in the synthesis. The CuII atom is located on an inversion centre and has a distorted octahedral [4 + 2]-coordination environment formed by four N atoms of two chelating bidentate 5-(pyrazin-2-yl)tetrazolate ligands at shorter distances and two water O atoms at longer distances. The CuII complex molecules are held together by O—H...N hydrogen bonds and π–π stacking interactions [centroid–centroid distance 3.6139 (8) Å], forming layers parallel to (100). These layers alternate with layers of pyrazine-2-carbonitrile molecules and both are held together via C—H...N hydrogen bonds and further π–π stacking interactions

l-Leucinium fluoride monohydrate

The asymmetric unit of the title hydrated salt, C6H14NO2+·F−·H2O, contains a discrete cation with a protonated amino group, a halide anion and one water molecule. The crystal structure is composed of double layers parallel to (010) held together by N—H...O, N—H...F, O—H...F and C—H...F hydrogen bonds, forming a two-dimensional network, and stacked along the c axis, viz. hydrophilic layers at z = 0 and 1/2 and hydrophobic layers at z = 1/3 and 2/3