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.     

rac‐(Z)‐Ethyl 2‐bromo‐2‐[(3R,5R)‐3‐bromo‐5‐methyl­tetra­hydro­furan‐2‐yl­idene]acetate

In the title compound, C₉H₁₂Br₂O₃, a (tetra­hydro­furan‐2‐yl­idene)acetate, the double bond has the Z form. In the tetra­hydro­furan group, the relative configuration of the Br atom in the 3‐position and the methyl group in the 5‐position is anti. The compound crystallizes with two independent mol­ecules per asymmetric unit and, in the crystal structure, the individual mol­ecules are linked to their symmetry‐equivalent mol­ecules by C—H⋯O hydrogen bonds, so forming centrosymmetric hydrogen‐bonded dimers.     

16‐(4‐Cyano­benzyl­idene)‐17‐oxo­androst‐5‐en‐3β‐ol

In the title compound, 4‐(3β‐hydroxy‐17‐oxoandrost‐5‐en‐16‐ylidenemethyl)benzonitrile, C₂₇H₃₁NO₂, rings A and C of the steroid nucleus are in chair conformations. The central six‐membered ring B is in an 8β,9α‐half‐chair conformation, while the five‐membered ring D adopts a 13β,14α‐half‐chair conformation. The cyano­benzyl­idene moiety has an E configuration with respect to the carbonyl group at position C17. The dihedral angle between the planes of the steroid nucleus and the cyano­benzyl­idene moiety is 22.61 (15)°. Intermolecular O—H⃛N hydrogen bonds formed between the hydroxyl group of the steroid and the N atom of the cyano­benzyl­idene moiety of symmetry‐related mol­ecules link the steroid mol­ecules into chains which run parallel to the b axis.     

2,6‐Diiodo‐4‐nitrophenol, 2,6‐diiodo‐4‐nitrophenyl acetate and 2,6‐diiodo‐4‐nitroanisole: interplay of hydrogen bonds,iodo–nitro interactions and aromatic π–π‐stacking interactions to give supramolecular structures in one,two and three dimensions

In 2,6‐di­iodo‐4‐nitro­phenol, C₆H₃I₂NO₃, the mol­ecules are linked, by an O—H?O hydrogen bond and two iodo–nitro interactions, into sheets, which are further linked into a three‐dimensional framework by aromatic π–π‐stacking interactions. The mol­ecules of 2,6‐di­iodo‐4‐nitro­phenyl acetate, C₈H₅I₂NO₄, lie across a mirror plane in space group Pnma, with the acetyl group on the mirror, and they are linked by a single iodo–nitro interaction to form isolated sheets. The mol­ecules of 2,6‐di­iodo‐4‐nitro­anisole, C₇H₅I₂NO₃, are linked into isolated chains by a single two‐centre iodo–nitro interaction.     

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.     

Triclinic and orthorhombic polymorphs of 2‐iodo‐4‐nitro­aniline: interplay of hydrogen bonds,nitro⃛I interactions and aromatic π–π‐stacking interactions

In the triclinic polymorph of 2‐iodo‐4‐nitro­aniline, C₆H₅IN₂O₂, space group P, the mol­ecules are linked by paired N—­H?O hydrogen bonds into C(8)[R(6)] chains of rings. These chains are linked into sheets by nitro?I interactions, and the sheets are pairwise linked by aromatic π–π‐stacking interactions. In the orthorhombic polymorph, space group Pbca, the mol­ecules are linked by single N—H?O hydrogen bonds into spiral C(8) chains; the chains are linked by nitro?O interactions into sheets, each of which is linked to its two immediate neighbours by aromatic π–π‐stacking inter­actions, so producing a continuous three‐dimensional ­structure.     

4‐Acetamido‐3,3,5,5‐[2H4]‐2,2,6,6‐tetra­([2H3]methyl)piperidin‐1‐yloxyl 0.33‐hydrate

The asymmetric unit of the title compound, C₁₁H₅D₁₆N₂O₂·0.33H₂O, is formed by three crystallographically independent piperidin‐1‐yloxyl mol­ecules and a mol­ecule of water. The mol­ecules are crosslinked by nine hydrogen bonds into layers parallel with the ac plane. The water mol­ecule contributes to the stability of the low‐symmetry arrangement by four hydrogen bonds.     

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.     

2‐(2,1‐Benzoxazol‐3‐yl)‐3,5‐di­methoxy­phenol and 3‐phenyl‐2,1‐benzoxazole

The title compounds, C₁₅H₁₃NO₄, (I), and C₁₃H₉NO, (II), are produced, along with the corresponding anilines, by the reduction of the appropriate o‐nitro­benzo­phenones. In (I), the planar benz­isoxazole and phenol fragments are tilted relative to one another by a rotation of 53.02 (14)° about the bond joining them, and the mol­ecules are linked into chains by phenol O—H...N and phenyl C—H...O_oxazole hydrogen bonds. The cell of (II) (space group I2/c) contains eight mol­ecules in general positions, four more in the 2b sites, with twofold axial symmetry that induces a degree of disorder, and a further four as centrosymmetric pairs of complete mol­ecules, each with an occupancy of one‐half. The relative tilt of the planar fragments varies slightly from one mol­ecule to another but is much less than that in (I), ranging from 8.8 (8) to 12.58 (15)°.     

β‐Lapachone

The most remarkable aspect of the crystal structure of the title compound (systematic name: 3,4‐dihydro‐2,2‐dimethyl‐2H‐naphtho[1,2‐b]pyran‐5,6‐dione), C₁₅H₁₄O₃, is that a π‐stacking inter­action is present between the two naphthalene ring systems of symmetry‐related mol­ecules. Apart from these π–π inter­actions, different mol­ecules are held together by weak C—H⋯O hydrogen‐bonding inter­actions.     

(±)‐6‐Benzyl‐3,3‐di­methyl­morpholine‐2,5‐dione and its 5‐mono­thio and 2,5‐di­thio derivatives

The morpholine ring of the title dione, C₁₃H₁₅NO₃, shows a boat conformation that is distorted towards a twist‐boat, with the boat ends being the two Csp³ atoms of the ring. The benzyl substituent is in the favoured `exo' position. In the mono­thione derivative, (±)‐6‐benzyl‐3,3‐di­methyl‐5‐thioxo­morpholin‐2‐one, C<sub>13</sub>H<sub>15</sub>NO<sub>2</sub>S, this ring has a much flatter conformation that is midway between a boat and an envelope, with the di­methyl end being almost planar. The orientation of the benzyl group is `endo'. The di­thione derivative, (±)‐6‐benzyl‐3,3‐di­methyl­morpholine‐2,5‐di­thione, C₁₃H₁₅N­OS₂, has two symmetry‐independent mol­ecules, which show different puckering of the morpholine ring. One mol­ecule has a flattened envelope conformation distorted towards a screw‐boat, while the conformation in the other mol­ecule is similar to that in the mono­thione derivative. Intermolecular hydrogen bonds link the mol­ecules in the three compounds, respectively, into centrosymmetric dimers, infinite chains, and dimers made up of one of each of the symmetry‐independent mol­ecules.     

Facial π⋯Cl⋯π inter­actions as the directing motif of the supra­molecular structures of Mg2+ and Ca2+ bis[hydro­tris(pyrazol­yl)­borate] chloro­form disolvates

The isomorphous complexes bis­[hydro­tris(pyrazol­yl)­borato]­mag­nesium(II) chloro­form disolvate, [Mg(C₉H₁₀BN₆)₂]·2CHCl₃, and bis­[hydro­tris(pyrazol­yl)borato]calcium(II) chloro­form disolvate, [Ca(C₉H₁₀BN₆)₂]·2CHCl₃, crystallize in the cubic space group Pa with Z = 4. The metal atoms occupy sites of symmetry, and their coordination is very similar to that found for the unsolvated Mg[HB(Pz)₃]₂ and Ca[HB(Pz)₃]₂ complexes (Pz is pyrazole). The inclusion of chloro­form mol­ecules on threefold rotation axes not only leads to high‐symmetry crystal structures but also plays an important role in stabilizing the three‐dimensional supramolecular architecture through facial Pz⋯Cl⋯Pz inter­actions.     

3‐Oxa‐6,8‐diaza‐1,2:4,5‐dibenzocycloocta‐1,4‐dien‐7‐one: a three‐dimensional network assembled by hydrogen‐bonding, π–π and edge‐to‐face interactions

The title compound, C₁₃H₁₀N₂O₂, is the first structure in which the urea moiety is incorporated into an eight‐membered ring. Two mol­ecules are found in the asymmetric unit, which are almost identical in their conformation and their hydrogen‐bond pattern. The carbonyl O atom acts as a double acceptor for the NH groups of two adjacent mol­ecules. In this way, infinite tapes are formed, which are connected viaπ–π and edge‐to‐face interactions in the second and third dimension. This hierarchical order of interactions is confirmed by molecular mechanics calculations. Force‐field and semi‐empirical calculations for a single mol­ecule did not find the envelope conformation present in the crystal, indicating instead a C_s conformation. Only with a model consisting of a hydrogen‐bonded dimer or a larger hydrogen‐bonded section was a conformation found that was similar to the one present in the crystal.     

Pentacarbonyl(4‐phenylpyridine)­tungsten(0) and pentacarbonyl(2‐phenylpyridine)chromium(0)

In penta­carbonyl(4‐phenyl­pyridine)­tungsten(0), [W­(C₁₁H₉N)(CO)₅], the mol­ecules have mm site symmetry and the pyridine ligand, with m symmetry, is completely planar. In penta­carbonyl(2‐phenyl­pyridine)­chromium(0), [Cr(C₁₁­H₉N)(CO)₅], the mol­ecules are in general positions and the phenyl and pyridine rings of the ligand are twisted by 67.7 (3)° with respect to one another by rotation about the C—C bond joining them. In both compounds, the axial M—C_carbonyl bond trans to the M—N_ligand bond is significantly shorter than the equatorial M—C_carbonyl bonds.     

(3R*,4R*)‐3‐Iso­propyl‐4‐phenyl­azetidin‐2‐one at 150 K

The title compound, C₁₂H₁₅NO, crystallized in the centrosymmetric space group C2/c with one mol­ecule as the asymmetric unit. There is a single conventional N—H?O hydrogen bond, with a donor–acceptor distance of 2.912 (1) Å, which forms an R(8) cyclic dimer about a center of symmetry. There is a single significant intermolecular C—H?O interaction, which also forms an R(8) cyclic dimer about a center of symmetry. Taken together, these interactions form chains propagating along [110]. Structural comparisons are made with another β‐­lactam, (1′R*,3R*,4S*)‐3‐(1′‐hydroxy­ethyl)‐4‐phenylazet­id­in‐2‐one.     

1:1 Adduct of (S,S)‐4‐amino‐3,5‐bis­(1‐hydroxy­ethyl)‐1,2,4‐triazole with (S,S)‐1,2‐bis­(2‐hydroxy­propionyl)­hydrazine stabilized by eight hydrogen bonds

The structure of the cocrystallized 1:1 adduct of (S,S)‐4‐amino‐3,5‐bis­(1‐hydroxy­ethyl)‐1,2,4‐triazole and (S,S)‐1,2‐bis­(2‐hydroxy­propionyl)­hydrazine, C₆H₁₂N₄O₂·C₆H₁₂N₂O₄, has tetra­gonal symmetry. All eight O‐ and N‐bound H atoms are involved in inter­molecular hydrogen bonds, resulting in infinite zigzag chains of the triazole mol­ecules, with the hydrazine mol­ecules filling the gaps between the chains and completing a three‐dimensional hydrogen‐bonded array.     

10‐(4‐Fluorophenyl)‐3,3,6,6,9‐pentamethyl‐3,4,6,7,9,10‐hexahydroacridine‐1,8(2H,5H)‐dione and 10‐(4‐fluorophenyl)‐3,3,6,6‐tetramethyl‐9‐­propyl‐3,4,6,7,9,10‐hexahydroacridine‐1,8(2H,5H)‐dione

10‐(4‐Fluoro­phenyl)‐3,3,6,6,9‐penta­methyl‐3,4,6,7,9,10‐hexa­hydro­acridine‐1,8(2H,5H)‐dione, C₂₄H₂₈FNO₂, (I), crystallizes with two crystallographically independent mol­ecules (which differ slightly in conformation), while 10‐(4‐fluoro­phenyl)‐9‐propyl‐3,3,6,6‐tetra­methyl‐3,4,6,7,9,10‐hexa­hydro­acridine‐1,8(2H,5H)‐dione, C₂₆H₃₂FNO₂, (II), crystallizes with one mol­ecule per asymmetric unit. In both structures, the central ring in the acridine moiety is in a sofa conformation, while the outer rings adopt intermediate half‐chair/sofa conformations. The central pyridine ring is orthogonal to the substituted phenyl ring. In both structures, the packing of the crystal is stabilized by C—H?O intermolecular hydrogen bonds.     

4′‐Hydro­xy­bi­phenyl‐4‐carbo­nitrile

The title compound, C₁₃H₉NO, crystallizes with four mol­ecules in the asymmetric unit. Each of the four crystallographically independent mol­ecules forms a chain parallel to the a axis with symmetry‐equivalent mol­ecules. These chains are held together by similar O—H·NC hydrogen bonds, with approximately linear O—H·N angles and significantly bent H·N—C angles. The four different mol­ecules are related by strong elements of pseudosymmetry. To better describe the pseudosymmetry, the structure has been reported in the non‐standard space group .     

4‐Chloro­aceto­phenone [1‐(4‐methoxyphenyl)­ethyl­idene]­hydra­zone

The crystal structure of the title mixed azine, C₁₇H₁₇ClN₂O, contains four independent mol­ecules, A–D, and mol­ecule B is disordered. All four mol­ecules have an N—N gauche conformation, with C—N—N—C torsion angles of 136.5 (4), 137.0 (4), ?134.7 (4) and ?134.7 (4)°, respectively. The phenyl rings are also somewhat twisted with respect to the plane defined by C_ipso and the imine bond. On average, the combined effect of these twists results in an angle of 64.7° between the best planes of the two phenyl rings. Arene–arene double T‐contacts are the dominant intermolecular inter­action. The methoxy‐substituted phenyl ring of one azine mol­ecule interacts to form a T‐contact with the methoxy‐substituted phenyl ring of an adjacent mol­ecule and, similarly, two chloro‐substituted phenyl rings of neighboring mol­ecules interact to form another T‐contact. The only exception is for mol­ecule B, for which the disorder leads to the formation of T‐­contacts between methoxy‐ and chloro‐substituted phenyl rings. The prevailing structural motif of T‐contact formation between like‐substituted arene rings results in a highly dipole‐parallel‐aligned crystal structure.     

2,6‐Dimethyl‐1,4‐benzoquinone 4‐monooxime

Mol­ecules of the title compound, C₈H₉NO₂, are linked into sheets by a combination of C—H·N, O—H·N and O—H·O hydrogen bonds and C—H·π inter­actions. The hydrogen bonds are arranged as described by the graph‐set ring notations R₂²(7) and R₃³(5), and a C8 chain motif. There are two planar symmetry‐independent mol­ecules in the asymmetric unit, with a dihedral angle of 19.24 (5)° between their least‐squares mean planes.