4‐Bromo‐2‐{[4‐(3‐mesityl‐3‐methyl­cyclo­butyl)thia­zol‐2‐yl]hydrazono­meth­yl}phenol,with N—H⋯N,C—H⋯π and π–π inter­actions

The title compound, C₂₄H₂₆BrN₃OS, crystallizes in the triclinic space group P, with two independent mol­ecules in the asymmetric unit. The mol­ecules adopt an E geometry about the azomethine C=N double bond. The structure is stabilized as dimers by N—H⋯N hydrogen bonding. C—H⋯π and π–π inter­actions are also effective in the crystal packing.     

5‐[N‐(1H‐Benzotriazol‐1‐yl­methyl)­amino]‐3‐tert‐butyl‐1‐phenyl­pyrazole: sheets built from N—H⋯N,C—H⋯N and C—H⋯π(pyrazole) interactions

In the title compound, C₂₀H₂₂N₆, the mol­ecules are linked into a chain of rings by N—H?N [H?N 2.16 Å, N?N 2.950 (3) Å and N—H?N 149°] and C—H?N [H?N 2.55 Å, C?N 3.481 (3) Å and C—H?N 165°] hydrogen bonds, and these chains are linked into sheets by means of C—­H?π(pyrazole) interactions.     

Crystal engineering via C—H⋯F and C—H⋯π interactions in two substituted indoles

The crystal structures of 1‐(4‐fluoro­phenyl)‐2‐phenyl‐4,5,6,7‐tetra­hydro‐1H‐indole, C₂₀H₁₈FN, and 1‐(4‐fluoro­phenyl)‐6,6‐di­methyl‐2‐phenyl‐4,5,6,7‐tetra­hydro‐1H‐indole, C₂₂H₂₂FN, have been determined in order to study the role of `organic fluorine' in crystal engineering. These mol­ecules pack in the crystal structure via different types of molecular motifs utilizing weak C—H⋯F and C—H⋯π interactions.     

C—H⋯π, π–π and C—H⋯Cl interactions in chloro‐substituted Schiff bases and 4‐chloro‐N‐[4‐(di­methyl­amino)­benzyl­idene]­aniline

Molecular packing analyses were carried out on 15 crystal data sets of chloro‐substituted Schiff bases, including that of the title compound, C₁₅H₁₅ClN₂. C—H⋯π and π–π interactions play a major role in the molecular self‐assembly in the crystal. The former interactions favor mol­ecules assembling into a screw, with a non‐centrosymmetric crystal structure. When the molecular dipole is small, π–π interactions favor a parallel, but not usually antiparallel, mode of packing. Weak C—H⋯X hydrogen bonds (X = Cl or Br) and X⋯X interactions seem to be a secondary driving force in packing. The title mol­ecule takes the trans form and the two benzene rings are twisted around the central linkage in opposite directions. In the crystal structure, mol­ecules interact through C—H⋯π and π–π interactions, forming a `dimer' and further forming double chains along [001]. The double chains are extended along [10] through C—H⋯Cl hydrogen bonds, forming double layers in (010). In the third direction, there are only ordinary, weaker, van der Waals interactions, which explains the crystal habit (i.e. thin plate).     

C—H⋯O,C—H⋯π and π–π inter­actions in three benzofuran‐2‐yl ketone derivatives

The mol­ecules of 2‐benzoyl‐1‐benzofuran, C₁₅H₁₀O₂, (I), inter­act through double C—H⋯O hydrogen bonds, forming dimers that are further linked by C—H⋯O, C—H⋯π and π–π inter­actions, resulting in a three‐dimensional supramolecular network. The dihedral angle between the benzo­yl and benzofuran fragments in (I) is 46.15 (3)°. The mol­ecules of bis­(5‐bromo‐1‐benzofuran‐2‐yl) ketone, C₁₇H₈Br₂O₃, (II), exhibit C₂ symmetry, with the carbon­yl group (C=O) lying along the twofold rotation axis, and are linked by a combination of C—H⋯O and C—H⋯π inter­actions and Br⋯Br contacts to form sheets. The stability of the mol­ecular packing in 3‐mesit­yl‐3‐methyl­cyclo­but­yl 3‐methyl­naphtho[1,2‐b]furan‐2‐yl ketone, C₂₈H₂₈O₂, (III), arises from C—H⋯π and π–π stacking inter­actions. The fused naphthofuran moiety in (III) is essentially planar and makes a dihedral angle of 81.61 (3)° with the mean plane of the trimethyl­benzene ring.     

4‐(Allyl­amino)‐2‐amino‐6‐benzyl­oxy‐5‐nitro­so­pyrimidine from synchrotron data at 150 K: double chains built from N—H⋯N,N—H⋯O,N—H⋯π(arene) and aromatic π–π‐stacking interactions

In the title compound, C₁₄H₁₅N₅O₂, the intramolecular dimensions are consistent with a highly polarized electronic structure. The mol­ecules are linked into chains by a combination of N—H?N, N—H?O and N—H?π(arene) hydrogen bonds, and the chains are linked in pairs by aromatic π–π‐stacking interactions     

Weak C–H⋯O and C–H⋯N ­interactions in nitro­pyrazoles

The structures of 1‐methyl‐3‐nitro­pyrazole and 1‐methyl‐4‐nitro­pyrazole, C₄H₅N₃O₂, have been determined. The 3‐nitro derivative has crystallographic m‐symmetry while the 4‐nitro compound has no imposed symmetry. The significant differences in bond distances and angles between the structures are ascribable to the electron‐withdrawing effects of the nitro group attached to C3 or C4, respectively. In both structures, the mol­ecules are organized into layers by an extensive network of C—H?O or C—H?N hydrogen interactions. Within a layer, the mol­ecules are arranged in a similar way, although differences of up to 0.3 Å in the analogous H?O or H?N intermolecular distances are observed. The cohesion of the layers is due to van der Waals and C—H?O contacts.     

N—H⋯N and C—H⋯π inter­actions in 4‐amino‐3‐methyl‐5‐(p‐tol­yl)‐4H‐1,2,4‐triazole and 4‐amino‐3‐methyl‐5‐phenyl‐4H‐1,2,4‐triazole

The title compounds, C₁₀H₁₂N₄, (I), and C₉H₁₀N₄, (II), have been synthesized and characterized both spectroscopically and structurally. The dihedral angles between the triazole and benzene ring planes are 26.59 (9) and 42.34 (2)°, respectively. In (I), mol­ecules are linked principally by N—H⋯N hydrogen bonds involving the amino NH₂ group and a triazole N atom, forming R₄⁴(20) and R₂⁴(10) rings which link to give a three‐dimensional network of mol­ecules. The hydrogen bonding is supported by two different C—H⋯π inter­actions from the tolyl ring to either a triazole ring or a tolyl ring in neighboring mol­ecules. In (II), inter­molecular hydrogen bonds and C—H⋯π inter­actions produce R₃⁴(15) and R₄⁴(21) rings.     

Bis(4‐nitro­phenyl) di­sulfide at 150 K,a three‐dimensional framework built from C—H⋯O hydrogen bonds and aromatic π⋯π stacking interactions

In the title compound, (4‐O₂NC₆H₄)₂S₂ or C₁₂H₈N₂O₄S₂, the mol­ecules lie across twofold rotation axes. A single type of C—H?O hydrogen bond, with C?O = 3.394 (3) Å and C—H?O = 158°, links the mol­ecules into continuous two‐dimensional sheets built from a single type of R⁴₄(44) ring. These sheets are linked by aromatic π?π stacking interactions to form a continuous three‐dimensional framework.     

Ethyl N‐(2‐benzyl­amino‐6‐benzyl­oxy‐5‐nitro­sopyrimidin‐4‐yl)­glycinate: sheets built from a three‐centre N—H⋯(N,O), and two‐centre C—H⋯O and C—H⋯π(arene) hydrogen bonds

In the title compound, C₂₂H₂₃N₅O₄, the mol­ecules are linked into chains by a three‐centre N—H?(N,O) hydrogen bond, reinforced by a two‐centre C—H?O hydrogen bond, and the chains are further linked into sheets by a combination of C—H?O and C—H?π(arene) hydrogen bonds.     

trans‐Dichloro­tetra­benzimidazole­cadmium(II) tetra­benzimidazole: a three‐dimensional supra­molecular structure built from C—H⋯π, N—H⋯Cl and N—H⋯N hydrogen bonds

The title compound, [CdCl₂(C₇H₆N₂)₄]·4C₇H₆N₂, consists of a Cd(Bzim)₄Cl₂ complex (Bzim is benzimidazole) lying on a fourfold rotation axis in the space group P4nc, and four benzimidazole mol­ecules which are linked to the coordinated benzimidazole unit by N—H⋯N hydrogen bonds. One N—H⋯Cl and three C—H⋯π hydrogen bonds link these units into a three‐dimensional supra­molecular structure.     

C—H⃛π interactions in 9‐(n‐do­decylamino­methyl)­anthracene

The title compound, C₂₇H₃₇N, which is intended to be included in the structure of a sulfon­amide porphyrin for the preparation of Langmuir–Blodgett films, consists of a do­decyl chain linked to an anthracene mol­ecule through an amino­methyl group. The angle between the least‐squares plane of the anthracene and the do­decyl chain is 11.44 (8)°. The mol­ecules are arranged in zigzag layers head‐to‐head, with the hydro­carbon chains side‐by‐side. The structure is stabilized by C—H?π interactions, the strongest having an H?centroid distance of 2.63 Å.     

Hydrogen‐bonding and C—H⋯π interactions in ethyl 4‐acetyl‐5‐methyl‐3‐phenyl‐1H‐pyrrole‐2‐carboxylate monohydrate

In the title compound, C₁₆H₁₇NO₃·H₂O, the pyrrole ring is distorted slightly from ideal C_2v symmetry. Three strong hydrogen bonds link the substituted pyrrole and water mol­ecules to form infinite chains, in which the hydrogen bonds form rings and chain patterns. Two intermolecular C—H?π interactions maintain the internal cohesion between these chains. The molecular structure differs slightly from that of the isolated mol­ecule calculated by ab initio quantum‐mechanical calculations. In the latter model, the non‐H substituent atoms share the plane of the pyrrole ring, except for the phenyl group, which lies almost perpendicular to this plane.     

Bis(3‐nitro­phenyl) di­sulfide forms no C—H⃛O hydrogen bonds

In the title compound, C₁₂H₈N₂O₄S₂, the mol­ecules lie across twofold rotation axes in the space group C2/c. There are no intermolecular C—H?O hydrogen bonds, but the mol­ecules are linked into chains along [001] by aromatic π?π stacking interactions.     

3′,4′‐Bis(4‐chloro­phenyl)­spiro­[chroman‐3,5′(4′H)‐isoxazol]‐4‐one

The title compound, C₂₃H₁₅Cl₂NO₃, crystallizes with two independent mol­ecules in the asymmetric unit. The chroman­one moiety consists of a benzene ring fused with a six‐membered heterocyclic ring which adopts a sofa conformation. The five‐membered spiro­isoxazoline ring is in an envelope conformation. The p‐chloro­phenyl rings bridged by the five‐membered ring are nearly perpendicular to each other. The chromanone moiety of one mol­ecule packs into the cavity formed by the p‐chloro­phenyl rings of a second mol­ecule through the formation of C—H?π interactions. The structure is stabilized by weak C—H?O, C—H?Cl and C—H?π interactions.     

Hydro­gen‐bonding and C—H⋯π interactions in 1,7‐bis(4‐hydroxy‐3‐methoxy­phenyl)­heptane‐3,5‐dione (tetra­hydro­curcumin)

The title compound, C₂₁H₂₄O₆, is the reduced form of curcumin, and exhibits important cosmoceutical properties. The mol­ecule is non‐planar and the benzene rings positioned at the ends of the heptane chain are orthogonally placed, with a dihedral angle of 84.09 (7)° between them. The molecular geometry and H‐atom locations reveal that the `heptane‐3,5‐dione' moiety exists in the keto–enol form, with the hydroxy H atom disordered over two adjacent sites. The packing of the mol­ecules in the lattice is directed by strong O—H⋯O intermolecular hydrogen bonds, which generate two‐dimensional sheets. These sheets are linked by C—H⋯O hydrogen bonds and weak C—H⋯π interactions to develop a three‐dimensional network.     

Hydro­gen bonding and C—H⋯O interactions in 3‐(3‐amino­phthal­imido)phthalic acid dihydrate

The title compound, C₁₆H₁₀N₂O₆·2H₂O, crystallized in the centrosymmetric triclinic space group P with one organic mol­ecule and two water mol­ecules as the asymmetric unit. Eight intermolecular hydrogen bonds have donor?acceptor distances in the range 2.602 (2)–3.289 (2) Å, with angles in the range 137 (2)–177 (2)°. These generate a three‐dimensional hydrogen‐bond network. There is a single intramolecular hydrogen bond. There are six significant intermolecular C—H?O interactions with H?O distances in the range 2.39–2.74 Å, and C—H?O angles in the range 131–157°.     

A mixed crystal of imperatorin and phellopterin,with C—H...O,C—H...π and π–π interactions

The crystal structure of 9‐(3‐methyl­but‐2‐enyl­oxy)­‐7H‐furo­[3,2‐g]­chro­men‐7‐one–4‐methoxy‐9‐(3‐methyl­but‐2‐enyl­oxy)‐7H‐­furo­[3,2‐g]­chromen‐7‐one (0.926/0.074), 0.926C₁₆H₁₄O₄·0.074C₁₇H₁₆O₅, is characterized by two independent imperatorin mol­ecules in the asymmetric unit, which exhibit different side‐chain conformations. A small amount of phellopterin overlaps with one of the two imperatorin mol­ecules. The supramol­ecular structure is supported by C—H...O, C—H...π and π–π interactions.     

9,9‐Dimethoxy‐7,11‐diphenyl‐2,4‐diazaspiro[5.5]undecane‐1,3,5‐trione monohydrate

Due to steric repulsions, the cyclo­hexane ring in the title compound, C₂₃H₂₄N₂O₅·H₂O, shows some bond‐length abnormalities and adopts a chair conformation. The pyrimidine and cyclo­hexane rings are approximately perpendicular to each other, and the phenyl rings are equatorial. C—H?π and N—H?O intermolecular interactions, as well as C—H?O inter‐ and intramolecular interactions, occur between the mol­ecules. In addition to van der Waals interactions, the water mol­ecule interacts with the pyrimidine­trione ring to stabilize the structure.     

C—H⃛O and C—H⃛π interactions in 1‐acetyl‐4‐(p‐chloro­benzyl­idene­amino)‐3‐ethyl‐4,5‐di­hydro‐1H‐1,2,4‐triazol‐5‐one

The title compound, C₁₃H₁₃ClN₄O₂, contains both a phenyl and a triazole ring, both of which are approximately coplanar with the entire mol­ecule. The triazole ring has substituents at the 1‐, 2‐ and 4‐positions. Intramolecular C—H⃛O and C—H⃛N interactions, together with intermolecular C—H⃛O and C—H⃛π interactions, help to stabilize the structure.