(E)‐1‐(2′‐Deoxy‐β‐d‐ribo­furan­osyl)‐2,4‐di­fluoro‐5‐(2‐iodo­vinyl)­benzene

This analysis of the title compound, C₁₃H₁₃F₂IO₃, establishes the orientation of (E)‐5‐(CH=CH—I) as antiperiplanar (ap) to the C—C bond (5–6 position) of the 2,4‐di­fluoro­phenyl ring system, with the (E)‐5‐(CH=CH—I) H atom located in close proximity (2.17 Å) to the F4 atom of the 2,4‐di­fluoro­phenyl moiety.     

Two isomers of 2,4‐di­benzyl‐8‐azabicyclo­[3.2.1]­octan‐3‐ol

The crystal structures of the title compounds, 2α,4α‐di­benzyl‐3α‐tropanol (2α,4α‐di­benzyl‐8‐methyl‐8‐aza­bi­cyclo­[3.2.1]­octan‐3α‐ol), C₂₂H₂₇NO, (I), and 2α,4α‐di­benzyl‐3β‐tropanol (2α,4α‐di­benzyl‐8‐methyl‐8‐aza­bi­cyclo­[3.2.1]­octan‐3β‐ol), C₂₂H₂₇NO, (II), show that both compounds have a piperidine ring in a chair conformation and a pyrrolidine ring in an envelope conformation. Isomer (I) is asymmetric, the benzyl groups having different orientations, whereas isomer (II) is mirror symmetric, and the N and O atoms, the C atom attached to the hydroxy group, and the methyl C atom attached to the N atom lie on the mirror plane. In the crystal structures of both (I) and (II), the mol­ecules are linked together by intermolecular O—H⋯N hydrogen bonds to form chains that run parallel to the a direction in (I) and parallel to b in (II).     

(±)‐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.     

rac‐ and meso‐3,3′‐Bis(3,5‐di­methyl­phenyl)‐3H,3′H‐2,2′‐biindenyl­idene‐1,1′(2H,2′H)‐dione

In the rac isomer of the title compound, C₃₄H₂₈O₂, the two C—Ph_{di­methyl­phenyl} bond axes make an angle of 58.7 (1)°. There is no short contact between the two 3,5‐di­methyl­phenyl rings, although the dihedral angle between them is 4.93 (7)°. The meso isomer has a center of symmetry at the middle of the C=C bond, and the two C—Ph_{di­methyl­phenyl} bond axes are antiparallel to one another.     

Self‐assembly of 2‐pivaloyl‐6‐chloro­pterin

In the title compound, N‐(6‐chloro‐4‐oxo‐3,4‐di­hydro­pteridin‐2‐yl)­‐2,2‐di­methyl­propan­amide, C₁₁H₁₂ClN₅O₂, the rings in the pterin moiety are planar. The amide carbonyl O atom is in syn‐periplanar conformation while the C—N—C—C propanamide linkage is antiperiplanar. The N—H?N and N—H?O intermolecular hydrogen bonds transform the mol­ecules into infinite chains.     

Supramolecular structures of 5‐[3‐(4‐methyl­phenyl)‐ and 5‐[3‐(4‐chloro­phenyl)‐2‐propenyl­idene]‐2,2‐di­methyl‐1,3‐dioxane‐4,6‐dione

2,2‐Di­methyl‐5‐[3‐(4‐methyl­phenyl)‐2‐propenyl­idene]‐1,3‐di­ox­ane‐4,6‐dione, C₁₆H₁₆O₄, crystallizes in the triclinic space group , with two mol­ecules in the asymmetric unit. These mol­ecules and a centrosymmetrically related pair, linked together by weak C—H?O hydrogen bonds, form a tetramer. 5‐[3‐(4‐Chloro­phenyl)‐2‐propenyl­idene]‐2,2‐di­methyl‐1,3‐dioxane‐4,6‐dione, C₁₅H₁₃ClO₄, also crystallizes in the triclinic space group , with one mol­ecule in the asymmetric unit. Centrosymmetrically related mol­ecules are linked together by weak C—H?O hydrogen bonds to form dimers which are further linked by yet another pair of centrosymmetrically related C—H?O hydrogen bonds to form a tube which runs parallel to the a axis.     

Racemic 3,5‐di­chloro‐2‐{[(1‐phenyl­ethyl)­imino]­methyl}phenol

The title compound, (RS)‐3,5‐di­chloro‐2‐{[(1‐phenyl­ethyl)­imino]­methyl}phenol, C₁₅H₁₃Cl₂NO, was synthesized from racemic 1‐phenyl­ethyl­amine and 3,5‐di­chloro­salicyl­aldehyde. The π‐conjugate system around the imine group is essentially planar in the phenol–imine tautomer. Intramolecular O⋯N hydrogen‐bond and intermolecular C—H⋯π interactions are present in the crystal structure.     

1‐Chloro‐3,6‐di­methoxy‐2,5‐di­methyl­benzene and 1‐chloro‐3,6‐di­methoxy‐2,4‐di­methyl­benzene

The title compounds, 1‐chloro‐3,6‐di­methoxy‐2,5‐di­methyl­benzene, (IIIa), and 1‐­chloro‐3,6‐di­methoxy‐2,4‐di­methyl­benzene, (IIIb), both C₁₀H₁₃ClO₂, were obtained from 2,5‐ and 2,6‐di­methyl‐1,4‐benzo­quinone, respectively, and are intermediates in the synthesis of ammonium quinone derivatives. The isomers have different substituents around the methoxy groups and crystallize in different space groups. In both mol­ecules, the methoxy groups each have different orientations with respect to the benzene ring. In both cases, one methoxy group lies in the plane of the ring and can participate in conjugation with the aromatic system, while the second is almost perpendicular to the plane of the aromatic ring. The C—O—C bond angles around these substituents are also different: 117.5 (4) and 118.2 (3)° in (IIIa) and (IIIb), respectively, when the methoxy groups lie in the plane of the ring, and 114.7 (3) and 113.6 (3)° in (IIIa) and (IIIb), respectively, when they are out of the plane of the ring.     

2‐Methyl‐1‐(4‐nitro­benzyl)pyridinium bis­(maleo­nitrile­di­thiol­ato)­nickelate(III)

In the title complex, 2‐methyl‐1‐(4‐nitro­benzyl)pyridinium bis(1,2‐di­cyano­ethene‐1,2‐di­thiol­ato)­nickelate(III), (C₁₃H₁₃N₂O₂)[Ni(C₄N₂S₂)₂], the most prominent general structural feature of the complex is the completely segregated columnar stacks of anions and cations. Within the cation column, there may be stacking interactions between adjacent nitro groups and benzene rings.     

6‐Amino‐2‐(3,4‐di­methoxy­benzyl­amino)‐3‐methyl‐5‐nitro­so­pyrimidin‐4(3H)‐one: hydrogen‐bonded sheets form interdigitated bilayers

Molecules of the title compound, C₁₄H₁₇N₅O₄, exhibit a highly polarized molecular–electronic structure. The mol­ecules are linked into sheets by two N—H⋯O hydrogen bonds [H⋯O = 2.03 and 2.02 Å, N⋯O = 2.836 (2) and 2.887 (2) Å, and N—H⋯O = 153 and 168°], augmented by a single C—H⋯O hydrogen bond [H⋯O = 2.47 Å, C⋯O = 3.403 (2) Å and C—H⋯O = 166°]. Pairs of sheets, related by inversion, form bilayers with interdigitated di­methoxy­benzyl substituents, weakly linked by a further C—H⋯O interaction [H⋯O = 2.50 Å, C⋯O = 3.350 (2) Å and C—H⋯O = 146°].     

5‐(2‐Pyridyl)‐1,3‐di­thia­ne‐2‐thione

The title compound, C₉H₉NS₃, crystallizes with two mol­ecules in the asymmetric unit. In both mol­ecules, the di­thia­ne‐2‐thione rings adopt a symmetric half‐boat conformation with the C atom opposite the C—S_thione bond out of the plane. The pyridine ring is in an equatorial position and is twisted out of the plane of the half‐boat by 82.7 (2) and 84.5 (2)° in the two mol­ecules, so that the N atom is trans to the axial C—H bond in both cases.     

2′,4′‐Di­hydroxy‐3‐methoxy‐α,β‐di­hydro­chalcone and 2′,4‐di­hydroxy‐α,β‐di­hydro­chalcone: supramolecular structures formed by O—H⋯O,C—H⋯O and stacking interactions

The crystal structures of 2′,4′‐di­hydroxy‐3‐methoxy‐α,β‐di­hydro­chalcone, C₁₆H₁₆O₄, and 2′,4‐di­hydroxy‐α,β‐di­hydro­chalcone, C₁₅H₁₄O₃, have been determined. In both compounds, the structure consists of two nearly planar six‐membered aromatic rings connected by a propanal chain, which is bent in the methoxy compound and almost straight in the other compound. In the crystal structures, the molecular units of both compounds are linked by O—H⋯O hydrogen bonds to form infinite one‐dimensional chains. Hydro­gen bonds and C—H⋯O contacts in the crystal structures were studied by topological analysis of charge density based on Hartree–Fock calculations. Almost all of the investigated C—H⋯O contacts should be characterized as weak hydrogen bonds.     

Di­propyl 3,6‐di­phenyl‐1,2‐di­hydro‐1,2,4,5‐tetrazine‐1,2‐di­carboxyl­ate

The title compound, C₂₂H₂₄N₄O₄, was prepared from propyl chloro­formate and 3,6‐di­phenyl‐1,2‐di­hydro‐s‐tetrazine. This reaction yields the title compound rather than di­propyl 3,6‐di­phenyl‐1,4‐di­hydro‐s‐tetrazine‐1,4‐di­carboxyl­ate. The 2,3‐di­aza­buta­diene group in the central six‐membered ring is not planar; the C=N double‐bond length is 1.285 (2) Å, and the average N—N single‐bond length is 1.401 (3) Å, indicating a lack of conjugation. The ring has a twist conformation, in which adjacent N atoms lie 0.3268 (17) Å from the plane of the ring. The mol­ecule has twofold crystallographic symmetry.     

Conformation of N‐methyl‐4‐piperidyl 2,4‐dinitrobenzoate

The crystal structure of N‐methyl‐4‐piperidyl 2,4‐di­nitro­benzoate, C₁₃H₁₅N₃O₆, (I), at 130 (2) K reveals that, in the solid state, the mol­ecule exists in the equatorial conformation, (Ieq). Thus, the through‐bond interaction present in the axial conformation, (Iax), is not strong enough to overcome the syn–diaxial interactions between the axial methyl substituent and the axial H atoms on the two piperidyl ring C atoms either side of the ester‐linked ring C atom. The carboxyl­ate group in (I) is orthogonal to the aromatic ring, in contrast with other 2,4‐di­nitro­benzoates, which are coplanar. The piperidyl–ester C—O bond distance is 1.467 (3) Å, which is actually shorter than other equatorial cyclo­hexyl–ester C—O distances. This shorter piperidyl–ester C—O bond distance is due to the reduced electron demand of the orthogonal ester group.     

2‐Iodo‐N‐(3‐nitrobenzyl)aniline and 3‐iodo‐N‐(3‐nitrobenzyl)aniline exhibit entirely different patterns of supramolecular aggregation

In 2‐iodo‐N‐(3‐nitro­benzyl)­aniline, C₁₃H₁₁IN₂O₂, the mol­ecules are linked into a three‐dimensional structure by a combination of C—H?O hydrogen bonds, iodo–nitro interactions and aromatic π–π‐stacking interactions, but N—H?O and C—H?π(arene) hydrogen bonds are absent. In the isomeric 3‐iodo‐N‐(3‐nitro­benzyl)­aniline, a two‐dimensional array is generated by a combination of N—H?O, C—H?O and C—H?π(arene) hydrogen bonds, but iodo–nitro interactions and aromatic π–π‐stacking interactions are both absent.     

Ethyl β‐{2‐[4‐(dimethylamino)phenyliminomethyl]‐1‐(phenylsulfonyl)indol‐3‐yl}acrylate

The title compound, C₂₈H₂₇N₃O₄S, crystallizes in the centrosymmetric space group P2₁/n, with one mol­ecule in the asymmetric unit. In the indole ring, the dihedral angle between the fused rings is 3.6 (1)°. The phenyl ring of the sulfonyl substituent makes a dihedral angle of 79.2 (1)° with the best plane of the indole moiety. The phenyl ring of the di­methyl­amino­phenyl group is orthogonal to the phenyl ring of the phenyl­sulfonyl group. The dihedral angle formed by the weighted least‐squares planes through the pyrrole ring and the phenyl ring of the di­methyl­amino­phenyl group is 7.8 (1)°. The molecular structure is stabilized by C—H?O and C—H?N interactions.     

Isomorphous dichloro‐ and dibromo(2‐methyl‐2‐phenyl­propyl)­phenylstannane,both displaying the same intramolecular π–π interaction at 120 K

The title compounds, di­chloro‐ and di­bromo­neophyl­phenyl­tin, [SnCl₂(C₆H₅)(C₁₀H₁₃)] and [SnBr₂(C₆H₅)(C₁₀H₁₃)], respectively, are remarkable for the `U' shape of the mol­ecules, whereby the two phenyl groups are brought face‐to‐face in an arrangement that permits intermolecular C—H⋯π bonds to connect the mol­ecules into layers parallel to (100). Intermolecular Sn–halide bonds are notably absent from the structures.     

Dichloro[1,1′‐(5,9‐dithia‐2,12‐diazoniatrideca‐1,12‐diene‐1,13‐diyl)dinaphthalen‐2‐olato‐κ2O,O′]dimethyltin(IV) acetonitrile solvate

Reaction of the potentially hexadentate ligand 1,9‐bis(2‐hydroxy‐1‐naphthalene­methyl­imino)‐3,7‐di­thia­nonane with di­methyl­tin chloride gave the title 1:1 adduct, in which the long ligand wraps around the SnCl₂Me₂ unit and in which the stereochemistry is fully trans. This compound crystallizes from aceto­nitrile as the 1:1 solvate [Sn(CH₃)₂(C₂₉H₃₀N₂­O₂S₂)Cl₂]·­C₂H₃N. During the reaction, the hydroxyl protons move to the N atoms. Most of the chemically equivalent bond lengths agree to within experimental uncertainty, but the Sn—Cl bond that is inside the ligand pocket is substantially longer than the Sn—Cl bond that points away from the long ligand [2.668 (1) versus 2.528 (1) Å]. The O—Sn—O angle is 166.0 (1)°. Comparison of the Sn—O, C—O and aryl C—C bond lengths with those of related compounds shows that the most important resonance forms for the Schiff base aryl­oxide ligand are double zwitterions, but that the uncharged resonance forms having carbonyl groups also contribute significantly.     

9,10‐Di­phenyl‐9,10‐epi­dioxy­anthra­cene and 9,10‐di­hydro‐10,10‐di­methoxy‐9‐phenyl­anthracen‐9‐ol

9,10‐Di­phenyl‐9,10‐epi­dioxy­anthracene, C₂₆H₁₈O₂, (I), was accidentally used in a photo­oxy­genation reaction that produced 9,10‐di­hydro‐10,10‐di­methoxy‐9‐phenyl­anthracen‐9‐ol, C₂₂H₂₀O₃, (II). In both compounds, the phenyl rings are approximately orthogonal to the anthracene moiety. The conformation of the anthracene moiety differs as a result of substitution. Intramolecular C—H⃛O interactions in (I) form two approximately planar S(5) rings in each of the two crystallographically independent mol­ecules. The packing of (I) and (II) consists of molecular dimers stabilized by C—H⃛O interactions and of molecular chains stabilized by O—H⃛O interactions, respectively.     

2‐(Acridin‐9‐yl­imino)‐3‐di­methyl­amino‐1,3‐thia­zolidin‐4‐one

In the title compound, C₁₈H₁₆N₄OS, prepared by the reaction of 4‐(acridin‐9‐yl)‐1,1‐di­methyl­thio­semicarbazide with methyl bromo­acetate, the acridine and thia­zolidine ring systems are both non‐planar and, because of steric requirements, almost perpendicular, with a dihedral angle between their planes of 99.69 (6)°. C—H·O and C—H·π(arene) hydrogen bonds stabilize the crystal structure in the solid state.