C[triple‐bond]C—H⋯N hydrogen bonding in 3‐methylthio‐4‐propargylthioquinoline

The title compound, C₁₃H₁₁NS₂, contains a C[triple‐bond]C—H?N hydrogen bond to a pyridine‐type N atom, with a C?N distance of 3.305 (4) Å and an H?N distance of 2.28 Å. This is one of the shortest C—H?N hydrogen bonds known.     

5‐Amino‐1‐benzoyl‐3‐methylpyrazole: complex sheets built from N—H...N,C—H...O and C—H...π(arene) hydrogen bonds

Molecules of the title compound [systematic name: (5‐amino‐3‐methylpyrazol‐1‐yl)(phenyl)methanone], C₁₁H₁₁N₃O, contain an intramolecular hydrogen bond. The molecules are linked into sheets by a combination of N—H...N, C—H...O and C—H...π(arene) hydrogen bonds. Comparisons are made with the hydrogen‐bonded structures of some related compounds.     

N—H...S and C—H...S hydrogen bonds in two tetraalkylammonium dithiobiurea(1–) inclusion compounds

Two inclusion compounds of dithiobiurea and tetrapropylammonium and tetrabutylammonium are characterized and reported, namely tetrapropylammonium carbamothioyl(carbamothioylamino)azanide, C₁₂H₂₈N⁺·C₂H₅N₄S₂⁻, (1), and tetrabutylammonium carbamothioyl(carbamothioylamino)azanide, C₁₆H₃₆N⁺·C₂H₅N₄S₂⁻, (2). The results show that in (1), the dithiobiurea anion forms a dimer via N—H...N hydrogen bonds and the dimers are connected into wide hydrogen‐bonded ribbons. The guest tetrapropylammonium cation changes its character to become the host molecule, generating pseudo‐channels containing the aforementioned ribbons by C—H...S contacts, yielding the three‐dimensional network structure. In comparison, in (2), the dithiobiurea anions are linked via N—H...S interactions, producing one‐dimensional chains which pack to generate two‐dimensional hydrogen‐bonded layers. These layers accommodate the guest tetrabutylammonium cations, resulting in a sandwich‐like layer structure with host–guest C—H...S contacts.     

Weak C—H...X (X = O,N) hydrogen bonds in the crystal structure of dihydroberberine

Dihydroberberine (systematic name: 9,10‐dimethoxy‐6,8‐dihydro‐5H‐1,3‐dioxolo[4,5‐g]isoquinolino[3,2‐a]isoquinoline), C₂₀H₁₉NO₄, a reduced form of pharmacologically important berberine, crystallizes from ethanol without interstitial solvent. The molecule shows a dihedral angle of 27.94 (5)° between the two arene rings at the ends of the molecule, owing to the partial saturation of the inner quinolizine ring system. Although lacking classical O—H or N—H donors, the packing in the crystalline state is clearly governed by C—H...N and C—H...O hydrogen bonds involving the two acetal‐type C—H bonds of the 1,3‐dioxole ring. Each dihydroberberine molecule is engaged in four hydrogen bonds with neighbouring molecules, twice as donor and twice as acceptor, thus forming a two‐dimensional sheet network that lies parallel to the (100) plane.     

Weak C—H...O hydrogen bonds in anisaldehyde,salicylaldehyde and cinnamaldehyde

In situ cryocrystallization has been employed to grow single crystals of 4‐methoxybenzaldehyde (anisaldehyde), C₈H₈O₂, 2‐hydroxybenzaldehyde (salicylaldehyde), C₇H₆O₂, and (2E)‐3‐phenylprop‐2‐enal (cinnamaldehyde), C₉H₈O, all of which are liquids at room temperature. Several weak C—H...O interactions of the types C_aryl—H...O, C_formyl—H...O and Csp³—H...O are present in these related crystal structures.     

Intermolecular C—H...O and C—H...X interactions in substituted spiroacenaphthylene structures

In the three spiroacenaphthylene structures 5′′‐[(E)‐2,3‐dichlorobenzylidene]‐7′‐(2,3‐dichlorophenyl)‐1′′‐methyldispiro[acenaphthylene‐1,5′‐pyrrolo[1,2‐c][1,3]thiazole‐6′,3′′‐piperidine]‐2,4′′‐dione, C₃₅H₂₆Cl₄N₂O₂S, (I), 5′′‐[(E)‐4‐fluorobenzylidene]‐7′‐(4‐fluorophenyl)‐1′′‐methyldispiro[acenaphthylene‐1,5′‐pyrrolo[1,2‐c][1,3]thiazole‐6′,3′′‐piperidine]‐2,4′′‐dione, C₃₅H₂₈F₂N₂O₂S, (II), and 5′′‐[(E)‐4‐bromobenzylidene]‐7′‐(4‐bromophenyl)‐1′′‐methyldispiro[acenaphthylene‐1,5′‐pyrrolo[1,2‐c][1,3]thiazole‐6′,3′′‐piperidine]‐2,4′′‐dione, C₃₅H₂₈Br₂N₂O₂S, (III), the substituted aryl groups are 2,3‐dichloro‐, 4‐fluoro‐ and 4‐bromophenyl, respectively. The six‐membered piperidine ring in all three structures adopts a half‐chair conformation, the thiazolidine ring adopts a slightly twisted envelope and the pyrrolidine ring an envelope conformation; in each case, the C atom linking the rings is the flap atom. In all three structures, weak intramolecular C—H...O interactions are present. The crystal packing is stabilized through a number of intermolecular C—H...O and C—H...X interactions, where X = Cl in (I) and F or S in (II), and C—H...O interactions are observed predominantly in (III). In all three structures, molecules are linked through centrosymmetric ring motifs, further tailored through a relay of C—H...X [Cl in (I), Br in (II) and O in (III)] interactions.     

3‐Methyl‐7‐(2‐thienyl)pyrido[2,3‐d]pyrimidine‐2,4(1H,3H)‐dione: π‐stacked bilayers built from N—H...O,C—H...O and C—H...π hydrogen bonds

In the title compound, C₁₂H₉N₃O₂S, the thienyl substituent is disordered over two sets of sites with occupancies of 0.749 (3) and 0.251 (3). A combination of N—H...O, C—H...O and C—H...π hydrogen bonds links the molecules into bilayers and these bilayers are themselves linked into a continuous structure by π–π stacking interactions.     

O‐Phenyl (triphenylphosphoniomethyl)phosphonate phenol solvate: supramolecular structure generated by O—H...O,C—H...O and C—H...π(arene) hydrogen bonds

The title compound, C₂₅H₂₂O₃P₂·C₆H₆O, has a zwitterionic betaine‐like structure and crystallizes as a phenol solvate. The two molecular components are held together by an almost linear intermolecular O—H...O hydrogen bond. The structure also contains three weak C—H...O and two C—H...π(arene) interactions.     

4‐(2‐Fluorophenyl)‐6‐(1H‐indol‐1‐yl)‐3‐methyl‐1‐phenyl‐1H‐pyrazolo[3,4‐b]pyridine‐5‐carbonitrile: a chain of rings built from N—H...N,C—H...N and C—H...π(arene) hydrogen bonds

In the title compound, C₂₈H₁₈FN₅, molecules are linked by a combination of N—H...N, C—H...N and C—H...π(arene) hydrogen bonds into complex double chains. The chains enclose cavities, four per unit cell, each of volume ca 102 ų and apparently containing disordered solvent.     

1‐(2‐Aminophenyl)‐3‐(4‐pyridyl)prop‐2‐en‐1‐one: a three‐dimensional framework structure built from N—H...N,C—H...O and C—H...π(arene) hydrogen bonds

The intramolecular dimensions of the title compound, C₁₄H₁₂N₂O, provide evidence for a polarized electronic structure. The molecule, which is almost completely planar, contains an intramolecular N—H...O hydrogen bond, and the molecules are linked by a combination of N—H...N, C—H...O and C—H...π(arene) hydrogen bonds to form a three‐dimensional framework structure.     

Octyl 1‐(5‐tert‐butyl‐1H‐pyrazol‐3‐yl)‐2‐(4‐chlorophenyl)‐1H‐benzimidazole‐5‐carboxylate: complex sheets built from N—H...N,C—H...N and C—H...O hydrogen bonds

In the title compound, C₂₉H₃₅ClN₄O₂, the bond lengths provide evidence for aromatic delocalization in the pyrazole ring but bond fixation in the fused imidazole ring, and the octyl chain is folded, rather than adopting an all‐trans chain‐extended conformation. A combination of N—H...N, C—H...N and C—H...O hydrogen bonds links the molecules into sheets, in which the hydrogen bonds occupy the central layer with the tert‐butyl and octyl groups arranged on either side, such that the closest contacts between adjacent sheets involve only the octyl groups. Comparisons are made with the supramolecular assembly in some simpler analogues.     

Naphthalene‐1,6‐diol: a three‐dimensional framework built from O—H...O,O—H...π and C—H...O hydrogen bonds

The asymmetric unit of the title compound, C₁₀H₈O₂, contains two practically planar symmetry‐independent molecules linked by one O—H...O hydrogen bond. Molecules are further linked into a three‐dimensional network, which is built from R₆⁶(36), R₆⁶(18), R₆⁶(30) and R₄⁴(26) rings formed by the combined effect of three O—H...O and one C—H...O hydrogen bond. This network is additionally stabilized by an O—H...π interaction.     

(2R*,4S*)‐2‐(Pyridin‐3‐yl)‐2,3,4,5‐tetrahydro‐1H‐1‐benzazepin‐4‐ol: a three‐dimensional framework built from O—H...N,C—H...O and C—H...π(arene) hydrogen bonds

The title compound, C₁₅H₁₆N₂O, crystallizes in the space group P2₁2₁2₁ with Z′ = 1. The seven‐membered ring adopts a chair‐type conformation with the hydroxy and pyridyl substituents in equatorial sites. Molecules are linked into a three‐dimensional framework structure by a combination of O—H...N, C—H...O and C—H...π(arene) hydrogen bonds, but N—H...O and N—H...π(arene) interactions are absent from the structure. Comparisons are made with some related compounds.     

2‐Cyano‐N‐(4,6‐dimethoxypyrimidin‐2‐yl)acetamide: complex sheets built from N—H...O and C—H...O hydrogen bonds

Molecules of the title compound, C₉H₁₀N₄O₃, (I), are linked into complex sheets by a combination of one N—H...O hydrogen bond and two C—H...O hydrogen bonds. Comparisons are drawn between (I) and some related compounds in respect of both their molecular conformations and their hydrogen‐bonding arrangements.     

(8RS)‐4‐Amino‐6‐(4‐chlorophenyl)‐8‐(2,4‐dichlorothiazol‐5‐yl)‐8,9‐dihydro‐7H‐pyrimido[4,5‐b][1,4]diazepine N,N‐dimethylformamide monosolvate: sheets built from N—H...N and C—H...O hydrogen bonds

In the title compound, C₁₆H₁₁Cl₃N₆S·C₃H₇NO, the seven‐membered ring adopts a conformation which is close to the twist‐boat form. The molecular components are linked into sheets by a combination of two N—H...N hydrogen bonds and two C—H...O hydrogen bonds. Comparisons are made with other aminopyrimidine derivatives.     

Cocrystals of 6‐propyl‐2‐thiouracil: N—H...O versus N—H...S hydrogen bonds

In order to investigate the relative stability of N—H...O and N—H...S hydrogen bonds, we cocrystallized the antithyroid drug 6‐propyl‐2‐thiouracil with two complementary heterocycles. In the cocrystal pyrimidin‐2‐amine–6‐propyl‐2‐thiouracil (1/2), C₄H₅N₃·2C₇H₁₀N₂OS, (I), the `base pair' is connected by one N—H...S and one N—H...N hydrogen bond. Homodimers of 6‐propyl‐2‐thiouracil linked by two N—H...S hydrogen bonds are observed in the cocrystal N‐(6‐acetamidopyridin‐2‐yl)acetamide–6‐propyl‐2‐thiouracil (1/2), C₉H₁₁N₃O₂·2C₇H₁₀N₂OS, (II). The crystal structure of 6‐propyl‐2‐thiouracil itself, C₇H₁₀N₂OS, (III), is stabilized by pairwise N—H...O and N—H...S hydrogen bonds. In all three structures, N—H...S hydrogen bonds occur only within R₂²(8) patterns, whereas N—H...O hydrogen bonds tend to connect the homo‐ and heterodimers into extended networks. In agreement with related structures, the hydrogen‐bonding capability of C=O and C=S groups seems to be comparable.     

7‐Amino‐5‐methyl‐2‐phenyl‐6‐(phenyldiazenyl)pyrazolo[1,5‐a]pyrimidine crystallizes with Z′ = 2: pseudosymmetry and the formation of complex sheets built from N—H...N and C—H...π(arene) hydrogen bonds

The title compound, C₁₉H₁₆N₆, crystallizes with Z′ = 2 in the space group P2₁/n. The two molecules in the selected asymmetric unit are approximate mirror images of one another; most corresponding pairs of atoms are related by an approximate half‐cell translation along [100]. Each molecule contains an intramolecular N—H...N hydrogen bond and the molecules are linked into complex sheets by a combination of two intermolecular N—H...N and four C—H...π(arene) hydrogen bonds. Comparisons are made with some other 7‐aminopyrazolo[1,5‐a]pyrimidines.     

2‐(4‐Chlorophenyl)‐5‐(4‐nitrophenyl)‐4,7‐dihydropyrazolo[1,5‐a]pyrimidine‐3,6‐dicarbaldehyde: a chain of rings built from N—H...O and C—H...O hydrogen bonds

In the title compound, C₂₀H₁₃ClN₄O₄, the six‐membered heterocyclic ring is planar and the molecular dimensions provide evidence for polarization of the molecular–electronic structure. Molecules are linked into a chain of rings by a combination of N—H...O and C—H...O hydrogen bonds, but the nitro group does not participate in the supramolecular aggregation. This study illustrates the marked influence of peripheral substituents on the pattern of hydrogen‐bonded aggregation in compounds of this type.     

2‐{[(Dodecylsulfanyl)carbonothioyl]sulfanyl}‐2‐methylpropanoic acid: a chain of edge‐fused R22(8) and R44(20) rings built from O—H...O and C—H...O hydrogen bonds

In the title compound, C₁₇H₃₂O₂S₃, the dodecyl chain and the trithiocarbonate unit adopt a nearly planar all‐trans conformation, while the carboxyl group is synclinal to this chain direction. The molecules are linked by pairs of inversion‐related O—H...O hydrogen bonds to form centrosymmetric dimers of R₂²(8) type, and dimers related by translation are linked by C—H...O hydrogen bonds to form a chain of edge‐fused rings, or a molecular ladder, containing alternating R₂²(8) and R₄⁴(20) rings.