Tris(1,9‐diethyl­adeninium) triiodide diiodide

X‐ray analysis of the title compound reveals three crystallographically distinct cations of 1,9‐diethyl­adeninium, two iodide anions and one triiodide anion in the asymmetric unit, giving six residues and the formula 3C₉H₁₄N₅⁺·I₃⁻·2I⁻. Standard purine nomenclature is used to identify the atoms of each adenine moiety. Hydrogen bonding is observed between atoms N6 and N7 of a pair of cations [N⋯N = 2.885 (4)/2.902 (3) and 2.854 (3)/2.854 (3) Å], with additional hydrogen bonding to I⁻ anions via the other N6 H atom [N⋯I = 3.708 (3), 3.738 (3) and 3.638 (3) Å]. The triiodide anion is not involved in hydrogen bonding. The bond lengths and angles of the 1,9‐diethyl­adeninium cations are compared with literature values and confirm the formation of the imine tautomer.     

9‐Cyano‐10‐methylacridinium hydrogen dinitrate

The title compound, C₁₅H₁₁N₂⁺·HN₂O₆^?, crystallizes in the monoclinic space group C2/c with four mol­ecules in the unit cell. The planar 9‐cyano‐10‐methyl­acridinium cations lie on crystallographic twofold axes and are arranged in layers, almost perpendicular to the ac plane, in such a way that neighbouring mol­ecules are positioned in a `head‐to‐tail' manner. These cations and the hydrogen dinitrate anions are linked through C—H?O interactions involving four of the six O atoms of the anion and the H atoms attached to the C atoms of the acridine moiety in ring positions 2 and 4. The H atom of the hydrogen dinitrate anion appears to be located on the centre of inversion relating two of the four O atoms engaged in the above‐mentioned C—H?O interactions. In this way, columns of either anions or cations running along the c axis are held in place by the network of C—H?O interactions, forming a relatively compact crystal lattice.     

An X‐ray powder investigation of catena‐poly[copper(II)‐di‐μ‐chloro‐κ41:2Cl‐μ‐1,5‐dimethyl‐1H‐tetra­zole‐κ2N3:N4]

The crystal structure of the polymeric title complex, [CuCl₂(C₃H₆N₄)]_n, has been solved from laboratory X‐ray powder diffraction data collected at room temperature. The structural model obtained was refined with the Rietveld method using geometric soft restraints. There are two Cu atoms, two Cl atoms and one 1,5‐dimethyl­tetra­zole ligand in the asymmetric unit. Both Cu atoms lie on inversion centres and adopt essentially elongated octa­hedral coordination. Within the octa­hedra, the elongated axial positions are occupied by Cl atoms, while two Cl and two N atoms (N3 and N4 of the tetra­zole ring) are in equatorial sites. Each Cl atom forms an asymmetric bridge between neighbouring Cu atoms, which are also bridged via the N3—N4 bond of the tetra­zole ring. These bridges result in the formation of polymeric chains, running along the a axis, with weak C—H⋯Cl hydrogen bonds crosslinking the chains.     

The perchlorate salt of the novel diprotonated dinucleating ligand 1,3‐bis­{[2‐(2‐pyridinio)eth­yl][2‐(2‐pyrid­yl)eth­yl]amino}benzene

In the title salt, 1,3‐bis­{[2‐(2‐pyridinio)eth­yl][2‐(2‐pyrid­yl)ethyl]amino}benzene diperchlorate dihydrate, C₃₄H₃₈N₆²⁺·2ClO₄⁻·2H₂O, the cation contains two ethyl­pyrid­yl and two ethyl­pyridinium pendant pairs anchored to the two N atoms of 1,3‐phenyl­enediamine. The pyrid­yl and pyridinium N atoms are flanked by a mol­ecule of water through strong hydrogen‐bonding inter­actions [N—H⋯O = 2.762 (6) and 2.758 (6) Å, and O—H⋯N = 2.834 (6) and 2.839 (6) Å]. The water mol­ecules have weak hydrogen‐bonding inter­actions with the perchlorate anions as well. One of the perchlorate anions is severely disordered.     

Hydro­gen‐bonding patterns in 2‐amino‐4,6‐di­methyl­pyrimidinium hydrogen sulfate

In the title compound, C₆H₁₀N₃⁺·HSO₄⁻, the asymmetric unit consists of a hydrogen sulfate anion and a 2‐amino‐4,6‐di­methyl­pyrimidinium cation. The hydrogen sulfate anions self‐assemble through O—H⋯O hydrogen bonds, forming supramolecular chains along the b axis, while the organic cations form base pairs via N—H⋯N hydrogen bonds. The amino­pyrimidinium cations join to the sulfate anions via a pair of hydrogen bonds donated from the pyrimidinium protonation site and from the exo amine group cis to the protonated site.     

μ‐1,4‐Benzenedicarboxylato‐bis[trans‐aqua(1,4,8,11‐tetraazacyclotetradecane)nickel(II)] diperchlorate forms a three‐dimensional hydrogen‐bonded framework

The title compound, [Ni₂(C₈H₄O₄)(C₁₀H₂₄N₄)₂(H₂O)₂](ClO₄)₂, contains two independent octahedral Ni^II centres with trans‐NiN₄O₂ chromophores. The bridging benzene­dicarboxyl­ate ligand is bonded to the two Ni atoms, each via one O atom of each carboxyl­ate, while the other O atom participates in an intramolecular N—H?O hydrogen bond, forming an S(6) motif. The cations are linked to the perchlorate anions via O—H?O and N—H?O hydrogen bonds [O?O 2.904 (6) and 2.898 (6) Å; O—H?O 158 (6) and 165 (6)°; N?O 3.175 (7) and 3.116 (7) Å; N—H?O 168 and 166°] to form molecular ladders. These ladders are linked by further O—H?O and N—H?O hydrogen bonds [O?O 2.717 (6) and 2.730 (5) Å; O—H?O 170 (4) and 163 (6)°; N?O 3.373 (7) and 3.253 (7) Å; N—H?O 163 and 167°] to form a continuous three‐dimensional framework. The perchlorate anions both participate in three hydrogen bonds, and both are thus fully ordered.     

Di­aqua­bis­[μ‐(R,R)‐tartrato‐κ4O1,O2:O3,O4]­dinickel(II) trihydrate

In the crystal structure of the title compound, [Ni₂(C₄H₄O₆)₂(H₂O)₂]·3H₂O, two nickel cations, two tartrate anions and two water mol­ecules form the dimeric complex. Each nickel cation is in a distorted octahedral environment composed of four O atoms of two crystallographically independent tartrate anions, one water mol­ecule and one O atom of a symmetry‐equivalent tartrate anion. The asymmetric unit contains three additional water mol­ecules which are connected via hydrogen bonding.     

Hydro­gen bonding in 1‐carbamoyl­guanidinium methyl­phospho­nate monohydrate

The title compound, C₂H₇N₄O⁺·CH₄O₃P⁻·H₂O, crystallized with one carbamoyl­guanidinium cation, one methyl­phos­phonate anion and one water mol­ecule in the asymmetric unit. All H atoms of the carbamoyl­guanidinium ion are involved in a hydrogen‐bonded network. The CH₃PO₂(OH) anions, together with the water mol­ecules, build O—H⋯O hydrogen‐bonded ribbons around a 2₁ screw axis parallel to the b axis. Neighbouring ribbons are not directly connected via hydrogen bonding. The carbamoyl­guanidinium cations are linked to these ribbons by N—H⋯O bridges and build a slightly buckled layer structure, the interlayer distance being b/2.     

Tris(2,2′‐bioxazoline‐κ2N,N′)copper(II) diperchlorate and tris(2,2′‐bioxazoline‐κ2N,N′)­nickel(II) diperchlorate

In the two isomorphous title compounds, viz. tris­[2,2′‐bi(4,5‐di­hydro‐1,3‐oxazole)‐κ²N,N′]copper(II) diperchlorate, [Cu(C₆H₈N₂O₂)₃](ClO₄)₂, (I), and tris­[2,2′‐bi(4,5‐di­hydro‐1,3‐oxazole)‐κ²N,N′]­nickel(II) diperchlorate, [Ni(C₆H₈N₂O₂)₃](ClO₄)₂, (II), the M^II ions each have a distorted octahedral coordination geometry formed via six N atoms from three 2,2′‐bioxazoline ligands. For each ligand, the two five‐membered rings are nearly coplanar. It is noteworthy that the Jahn–Teller effect is stronger in (I) than in (II). The three‐dimensional supramolecular structures of (I) and (II) are formed via weak hydrogen‐bonding interactions between O atoms from per­chlorate anions and H atoms from 2,2′‐bioxazoline ligands.     

2,3‐Difluoro‐4‐formyl­phenyl­boronic acid

The mol­ecule of the title compound, 2,3‐F₂‐4‐(CHO)C₆H₂B(OH)₂ or C₇H₅BF₂O₃, contains a formyl group coplanar with the benzene ring. The boronic acid group is twisted with respect to the benzene ring plane. The mol­ecules are organized into infinite chains via inter­molecular O—H⋯O hydrogen bonds. These chains are additionally connected via strong O—H⋯O hydrogen bonds, producing a folded layer structure perpendicular to the a axis. These layers are paired due to B⋯F inter­actions.     

4‐Aminopyridinium 4‐aminobenzoate dihydrate and 4‐aminopyridinium nicotinate

In the title compounds, 4‐aminopyridinium 4‐aminobenzoate dihydrate, C₇H₆NO₂⁻·C₅H₇N₂⁺·2H₂O, (I), and 4‐aminopyridinium nicotinate, C₅H₇N₂⁺·C₆H₄NO₂⁻, (II), the aromatic N atoms of the 4‐aminopyridinium cations are protonated. In (I), the asymmetric unit is composed of two 4‐aminopyridinium cations, two 4‐aminobenzoate anions and four water molecules, and the compound crystallizes in a noncentrosymmetric space group. The two sets of independent molecules of (I) are related by a centre of symmetry which is not part of the space group. In (I), the protonated pyridinium ring H atoms are involved in bifurcated hydrogen bonding with carboxylate O atoms to form an R₁²(4) ring motif. The water molecules link the ions to form a two‐dimensional network along the (10) plane. In (II), an intramolecular bifurcated hydrogen bond generates an R₁²(4) ring motif and inter‐ion hydrogen bonding generates an R₄²(16) ring motif. The packing of adduct (II) is consolidated via N—H...O and N—H...N hydrogen bonds to form a two‐dimensional network along the (10) plane.     

1,4‐Di­aza­bi­cyclo­[2.2.2]­octane‐1,4‐diium trichromate

The title compound, (C₆H₁₄N₂)[Cr₃O₁₀], consists of a di­aza­bi­cyclo­[2.2.2]­octane‐1,4‐diium cation and a discrete trichromate anion linked by an N—H⋯O hydrogen bond. Three CrO₄ tetrahedra are joined via shared O atoms to form the trichromate anion. Supramolecular rings, which can be described by the graph‐set motif (26), are built via N—H⋯O hydrogen bonds, and C—H⋯O interactions play lesser roles in forming the structure.     

catena‐Poly[[(2,2′‐biimidazole‐κ2N,N′)chloro­copper(II)]‐μ‐chloro]

In the polymeric title compound, [CuCl₂(C₆H₆N₄)]_n, each Cu^II ion is five‐coordinated by four basal atoms (two N atoms from a 2,2′‐biimidazole mol­ecule and two Cl⁻ anions) and one axial Cl⁻ anion, in a distorted square‐pyramidal coordination geometry. Cl⁻ anions bridge the {Cu(C₆H₆N₄)Cl} units into one‐dimensional linear chains, which are reinforced by π–π inter­actions. Adjacent linear chains are linked by N—H⋯Cl hydrogen bonds, resulting in a grid layer. The hydrogen‐bonding pattern can be described in graph‐set notation as C(9)R(9)R(14). This study extends our knowledge of the multifunctional properties of the 2,2′‐biimidazole ligand and of the coordination stereochemistry of copper(II).     

Tris(1,10‐phenanthroline)sodium 2,4,6‐trimercapto‐1,3,5‐triazin‐1‐ide

The title compound, [Na(C₁₂H₈N₂)₃](C₃H₂N₃S₃), contains an Na⁺ centre which is ionicly bonded to three 1,10‐phenanthroline (phen) ligands and one tri­thio­cyanurate(1−) (ttcH₂) anion. In the crystal structure, the anions are linked via hydrogen bonds to form linear chains. The S and H atoms of the ttcH₂ anion participate in intermolecular N—H⋯S hydrogen bonding, with N⋯S distances of 3.298 (2) and 3.336 (2) Å. The phen ligands are almost parallel, with dihedral angles of 3.92 (5), 11.75 (5) and 15.45 (5)°; moreover, they are nearly perpendicular to the ttcH₂ chains, with angles of 81.94 (7), 85.86 (7) and 85.96 (7)°.     

(E)‐6‐Methoxy‐3‐(α‐methoxybenzyl­idene)benzo[b]furan‐2(3H)‐one at 173 K

The title compound, C₁₇H₁₄O₄, is an unprecedented new synthetic isoaurone‐type enol ether that has the E configuration. The planar furanone ring is fused to a methoxy­benzene ring system, with an interplanar angle of 175.7 (1)°. Due to this ring fusion, the six‐membered ring has a significant amount of ring strain, as shown by the internal ring angle range of 115.8 (1)–124.7 (1)°, whereas the vinylic phenyl ring has internal angles between 119.7 (1) and 120.2 (1)°. The mol­ecules form infinite hydrogen‐bonding layers along the b direction of the form C—H?O, where the keto O atom acts as a bifurcated acceptor. These layers are connected along the c direction by another hydrogen bond with a methoxy H atom as donor. In addition to this connection, the layers are stacked via centres of symmetry by a pair of symmetry‐related benzo­furan­one ring systems.     

Di­chloro­bis­(imidazolidin‐2‐one‐κO)­zinc(II) at 150 K

In the title compound, [ZnCl₂(C₃H₆N₂O)₂], the zinc(II) cation is surrounded by a distorted tetrahedral environment consisting of two Cl anions and two imidazolidin‐2‐one mol­ecules, the latter bound to the metal through their carbonyl O atoms. All atoms that are able to participate in hydrogen bonding are involved in such interactions. A hydrogen‐bonding network mediates the formation of mol­ecular columns parallel to the a axis. Neighboring columns are not bound by significant non‐covalent interactions; the result is an extended pattern of supramolecular aggregation that is intermediate in completeness between the situations observed in two related complexes of cobalt that have been studied previously.     

Ethyl 2‐amino‐4‐phenyl‐1,3‐thia­zole‐5‐carboxyl­ate

The structure of the title compound, C₁₂H₁₂N₂O₂S, (I), comprises mol­ecules that form dimers via N—H?N hydrogen‐bonding interactions and then construct the overall network through N—H?O associations. The dihedral angle between the phenyl and thia­zole rings is 42.41 (6)°.     

2,4‐Diamino‐5‐(1‐naphthyl)‐3,5‐diaza‐1‐azoniaspiro[5.5]undeca‐1,3‐diene chloride

The title salt, C₁₈H₂₂N₅⁺·Cl^?, is a member of a new series of lipophilic 4,6‐di­amino spiro‐s‐triazines which are potent in­hib­itors of di­hydro­folate reductase. The protonated triazine ring deviates from planarity, whereas the cyclo­hexane ring adopts a chair conformation. A rather unusual hydrogen‐bonding scheme exists in the crystal. There is a centrosymmetric arrangement involving two amino groups and two triazine ring N atoms, with graph‐set R(8) and an N?N distance of 3.098 (3) Å, flanked by two additional R(8) systems, involving two amino groups, a triazine ring N atom and a Cl^? anion, with N?Cl distances in the range 3.179 (2)–3.278 (2) Å. Furthermore, the Cl^? anion, the protonated triazine ring N atom and an amino group form a hydrogen‐bonding system with graph‐set R(6).     

3,4‐Di‐2‐pyridyl‐1,2,5‐oxadiazole and its perchlorate salt

In 3,4‐di‐2‐pyridyl‐1,2,5‐oxadiazole (dpo), C₁₂H₈N₄O, each mol­ecule resides on a twofold axis and inter­acts with eight neighbours via four C—H⋯N and four C—H⋯O inter­actions to generate a three‐dimensional hydrogen‐bonded architecture. In the perchlorate analogue, 2‐[3‐(2‐pyrid­yl)‐1,2,5‐oxadiazol‐4‐yl]pyridinium perchlorate, C₁₂H₉N₄O⁺·ClO₄⁻ or [Hdpo]ClO₄, the [Hdpo]⁺ cation is bisected by a crystallographic mirror plane, and the additional H atom in the cation is shared by the two pyridyl N atoms to form a symmetrical intra­molecular N⋯H⋯N hydrogen bond. The cations and perchlorate anions are linked through C—H⋯O hydrogen bonds and π–π stacking inter­actions to form one‐dimensional tubes along the b‐axis direction.     

2‐[6‐(1H‐Benzimidazol‐2‐yl)‐2‐pyridyl]‐1H‐benzimidazol‐3‐ium perchlorate monohydrate

The title compound, C₁₉H₁₄N₅⁺·ClO₄^?·H₂O, contains planar C₁₉H₁₄N₅⁺ cations, perchlorate anions and water mol­ecules. The two closest parallel cations (plane‐to‐plane distance of 3.41 Å), together with two neighbouring perchlorate anions and two water mol­ecules, form an electrically neutral quasi‐dimeric unit. Two acidic H atoms of the cation, both H atoms of the water mol­ecule, the N atoms of the imidazole rings and three of the four O atoms of the perchlorate anion are involved in the hydrogen‐bonding network within the dimeric unit. The remaining third acidic H atom of the imidazole rings and the water mol­ecules complete a two‐dimensional network of hydrogen bonds, thus forming puckered layers of dimers. The angle between the planes of two neighbouring dimeric units in the same layer is 33.25 (3)°.