Three‐dimensional aggregation in 2‐hydroxy‐3‐iodo‐5‐nitrobenzaldehyde involving C—H⋯O,iodo–nitro and aromatic π–π stacking interactions,and isolated dimers in disordered 2,4‐diiodo‐6‐nitroanisole

In 2‐hydroxy‐3‐iodo‐5‐nitro­benz­aldehyde, C₇H₄INO₄, the mol­ecules are linked into sheets by a combination of C—H⋯O hydrogen bonds and two‐centre iodo–nitro interactions, and these sheets are linked by aromatic π–π stacking interactions. Molecules of 2,4‐di­iodo‐6‐nitro­anisole, C₇H₅I₂NO₃, are disordered, with the nitro group and one of the I substituents each occupying common sets of sites with 0.5 occupancy. The mol­ecules are linked into isolated centrosymmetric dimeric units by a single iodo–nitro interaction.     

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.     

Hydrogen bonding in nitroaniline analogues: hydrogen‐bonded sheets in 2‐amino‐4,6‐dimethoxy‐5‐nitropyrimidine and π‐stacked hydrogen‐bonded sheets in 4‐amino‐2,6‐dimethoxy‐5‐nitropyrimidine

In 2‐amino‐4,6‐di­methoxy‐5‐nitro­pyrimidine, C₆H₈N₄O₄, the mol­ecules are linked by one N—H⋯N and one N—H⋯O hydrogen bond to form sheets built from alternating R(8) and R(32) rings. In isomeric 4‐amino‐2,6‐di­methoxy‐5‐nitro­pyrimidine, C₆H₈N₄O₄, which crystallizes with Z′ = 2 in P, the two independent mol­ecules are linked into a dimer by two independent N—H⋯N hydrogen bonds. These dimers are linked into sheets by a combination of two‐centre C—H⋯O and three‐centre C—H⋯(O)₂ hydrogen bonds, and the sheets are further linked by two independent aromatic π–π‐stacking interactions to form a three‐dimensional structure.     

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.     

Ethyl N‐[2‐(hydroxy­acetyl)­phenyl]­carbamate,ethyl N‐[2‐(hydroxy­acetyl)‐4‐iodo­phenyl]­carbamate and ethyl N‐[2‐(hydroxy­acetyl)‐4‐methyl­phenyl]­carbamate

In ethyl N‐[2‐(hydroxy­acetyl)phenyl]carbamate, C₁₁H₁₃NO₄, all of the non‐H atoms lie on a mirror plane in the space group Pnma; the mol­ecules are linked into simple chains by a single C—H⋯O hydrogen bond. The mol­ecules of ethyl N‐[2‐(hydroxy­acetyl)‐4‐iodo­phenyl]carbamate, C₁₁H₁₂INO₄, are linked into sheets by a combination of O—H⋯I and C—H⋯O hydrogen bonds and a dipolar I⋯O contact. Ethyl N‐­[2‐(hydroxy­acetyl)‐4‐methyl­phenyl]carbamate, C₁₂H₁₅NO₄, crystallizes with Z′ = 2 in the space group P; pairs of mol­ecules are weakly linked by an O—H⋯O hydrogen bond and these aggregates are linked into chains by two independent aromatic π–π stacking inter­actions.     

1‐Chloro‐2‐nitro­benzene: N—O⋯Cl halogen bonds and aromatic π–π stacking,and thermal vibrations in the vicinity of the melting point

The crystal structure of 1‐chloro‐2‐nitro­benzene, C₆H₄ClNO₂, is made up of mol­ecules which are linked by N—O⋯Cl halogen bonds. These mol­ecular chains are involved in aromatic π–π stacking; the inter­molecular O⋯Cl distance is 3.09 Å. Such short halogen bonds are not common. A rigid‐body analysis including the non‐rigidly attached rigid group provides the mean‐square amplitudes of the mol­ecular translations and librations, and of the inter­nal torsional vibrations of the nitro group. The results reveal the driving role of the torsional vibrations of the nitro group in the phase transition to the liquid phase.     

Four (E,Z,E)‐1‐(4‐alkoxy­phen­yl)‐6‐(4‐nitro­phen­yl)hexa‐1,3,5‐trienes

The crystal structures of the four E,Z,E isomers of 1‐(4‐alk­oxy­phen­yl)‐6‐(4‐nitro­phen­yl)hexa‐1,3,5‐triene, namely (E,Z,E)‐1‐(4‐methoxy­phen­yl)‐6‐(4‐nitro­phen­yl)hexa‐1,3,5‐triene, C₁₉H₁₇NO₃, (E,Z,E)‐1‐(4‐ethoxy­phen­yl)‐6‐(4‐nitro­phen­yl)hexa‐1,3,5‐triene, C₂₀H₁₉NO₃, (E,Z,E)‐1‐(4‐nitro­phen­yl)‐6‐(4‐n‐propoxyphen­yl)hexa‐1,3,5‐triene, C₂₁H₂₁NO₃, and (E,Z,E)‐1‐(4‐n‐butoxy­phen­yl)‐6‐(4‐nitro­phen­yl)hexa‐1,3,5‐triene, C₂₂H₂₃NO₃, have been determined. Inter­molecular N⋯O dipole inter­actions between the nitro groups are observed for the meth­oxy derivative, while for the eth­oxy derivative, two adjacent mol­ecules are linked at both ends through N⋯O dipole–dipole inter­actions between the N atom of the nitro group and the O atom of the eth­oxy group to form a supra­molecular ring‐like structure. In the crystal structures of the n‐prop­oxy and n‐but­oxy derivatives, the shortest inter­molecular distances are those between the two O atoms of the alk­oxy groups. Thus, the nearest two mol­ecules form an S‐shaped supra­molecular dimer in these crystal structures.     

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.     

N,N′‐Di­thio­bisphthal­imide–nitro­benzene (2/1): a Pn solvate with localized solvent mol­ecules ordered head‐to‐tail in channels

N,N′‐Di­thio­bisphthal­imide crystallizes from nitro­benzene solution as a solvate, 2C₁₆H₈N₂O₄S₂·C₆H₅NO₂, having space group Pn. The bisphthal­imide mol­ecules are linked by C—H?O hydrogen bonds and by aromatic π–π‐stacking interactions, forming a framework enclosing continuous channels running along the [100] direction and accounting for ca 20% of the unit‐cell volume. The nitro­benzene mol­ecules lie in these channels, ordered in a head‐to‐tail fashion and linked to the bis­phthal­imide framework by C—H?O and C—H?π(arene) hydrogen bonds.     

(Z)‐2‐(3‐Methoxy­benzyl­idene)‐1‐aza­bicyclo­[2.2.2]octan‐3‐one

The crystal structure of the title compound, C₁₅H₁₇NO₂, contains two nearly identical but crystallographically independent mol­ecules, each with a double bond connecting an aza­bicyclic ring system to a 3‐methoxy­benzyl­idene moiety. The space group is triclinic P. The benzene ring is twisted by 18.44 (5) and 22.35 (4)° with respect to the plane of the double bond connected to the azabicyclic ring system for the two mol­ecules. In addition to C—H⋯π inter­actions, mol­ecules are held together in the solid state by van der Waals inter­actions.     

Tri­phenyl(3,4,5‐tri­iodo­phenyl)­methane

The crystal structure of the title compound, alternatively called 1,2,3‐triiodo‐5‐(triphenylmethyl)benzene, C₂₅H₁₇I₃, is analysed in terms of I⋯I and I⋯π interactions and the herring‐bone T motif between phenyl groups. There are two mol­ecules in the asymmetric unit, denoted A and B. Inversion‐related A mol­ecules are connected via an I⋯π interaction (3.641 Å, to a C—C bond mid‐point) to form an I⋯π dimer, and these dimers are connected through symmetry‐independent B mol­ecules via I⋯I [3.5571 (15) Å] and I⋯π (3.561 Å, to a C—C bond mid‐point) interactions.     

4‐[(2‐Chloro­phenyl)­diazenyl]‐6‐methoxy‐2‐{[tris­(hydroxy­methyl)­methyl]­amino­methyl­ene}cyclo­hexa‐3,5‐dien‐1(2H)‐one

The structure of the title compound, C₁₈H₂₀ClN₃O₅, displays the characteristic features of azo­benzene derivatives. Intramolecular N—H⋯O, weak intramolecular C—H⋯O, and intermolecular O—H⋯O and C—H⋯O interactions influence the conformation of the mol­ecules and the crystal packing. Intermolecular hydrogen bonds link the mol­ecules into infinite chains, and the title compound adopts the keto–amine tautomeric form. The azo­benzene moiety of the mol­ecule has a trans configuration. The mol­ecule is not planar, and the dihedral angle between the two phenyl rings is 35.6 (2)°.     

Hydrogen‐bonded supra­molecular arrays of aqua­[20‐(4‐carboxy­phen­yl)‐5,10,15‐triphenyl­porphyrinato]zinc(II) in crystals of its nitro­benzene disolvate

Crystals of the title compound, [Zn(C₄₅H₂₈N₄O₂)(H₂O)]·2C₆H₅NO₂, consist of multiporphyrin supra­molecular assemblies sustained by inter­molecular COOH⋯COOH and Zn(H₂O)⋯COOH hydrogen bonds. One of the two nitro­benzene solvent mol­ecules hydrogen bonds peripherally to these arrays.     

1‐(4‐Chloro­phenyl­sulfanyl)‐2‐nitro‐4‐(tri­fluoro­methyl)­benzene and 1‐(4‐chloro­phenyl­sulfanyl)‐4‐nitro‐2‐(tri­fluoro­methyl)­benzene

Two chemical isomers of 3‐nitro­benzotrifluoride, namely 1‐(4‐chloro­phenyl­sulfanyl)‐2‐nitro‐4‐(tri­fluoro­methyl)­benzene, C₁₃H₇ClF₃NO₂S, (I), and 1‐(4‐chloro­phenyl­sulfanyl)‐4‐nitro‐2‐(tri­fluoro­methyl)­benzene, C₁₃H₇ClF₃NO₂S, (II), have been prepared and their crystal structures determined with the specific purpose of forming a cocrystal of the two. The two compounds display a similar conformation, with dihedral angles between the benzene rings of 83.1 (1) and 76.2 (1)°, respectively, but (I) packs in P while (II) packs in P2₁/c, with C—H⋯O interactions. No cocrystal could be formed, and it is suggested that the C—H⋯O associations in (II) prevent intermolecular mixing and promote phase separation.     

3,5‐Bis(4‐methoxy­benzyl­idene)‐1‐methyl‐4‐piperidone and 3,5‐bis(4‐methoxy­benzyl­idene)‐1‐methyl‐4‐oxopiperidinium chloride: potential biophotonic materials

In the title compound 3,5‐bis(4‐methoxy­benzyl­idene)‐1‐methyl‐4‐piperidone, C₂₂H₂₃NO₃, (I), the central heterocyclic ring adopts a flattened boat conformation, while in the related salt 3,5‐bis(4‐methoxy­benzyl­idene)‐1‐methyl‐4‐oxopiperidin­ium chloride, C₂₂H₂₄NO₃⁺·Cl⁻, (II), the ring exhibits a `sofa' conformation in which the N atom deviates from the planar fragment. The pendant benzene rings are twisted from the heterocyclic ring planes in both mol­ecules in the same direction, the range of dihedral angles between the ring planes being 24.5 (2)–32.7 (2)°. The dominant packing motif in (I) involves centrosymmetric dimers bound by weak intermolecular C—H⋯O hydrogen bonds. In (II), cations and anions are linked by strong N—H⋯Cl hydrogen bonds, while weak C—H⋯O and C—H⋯Cl hydrogen bonds link the cations and anions into a three‐dimensional framework.     

1‐Methyl‐1‐phenyl‐3‐[1‐hydroxy­imino‐2‐(succinimido)­ethyl]­cyclo­butane

In the title compound, C₁₇H₂₀N₂O₃, the cyclo­butane ring is puckered, with a dihedral angle of 19.11 (15)°. The 1‐phenyl and 3‐[1‐hydroxy­imino‐2‐(succinimido)­ethyl] groups are in cis positions. The mol­ecules are linked by O—H⋯O and C—H⋯π(benzene) interactions, forming a two‐dimensional network.     

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).     

3‐Hydro­xy‐6‐[(4‐hydroxy­phenyl­amino)­methyl­ene]­cyclo­hexa‐2,4‐dienone and 2‐hydroxy‐6‐[(4‐hydroxy­phenyl­amino)­methyl­ene]­cyclo­hexa‐2,4‐dienone

The title compounds, both C₁₃H₁₁NO₃, exist as the keto–amine tautomers, and the formal hydroxyl H atoms, which display strong intramolecular hydrogen bonds, are located on the N atoms. This is a verification of the preference for the keto–amine tautomeric form in the solid state. The 2‐hydroxy isomer has two independent mol­ecules, with the mol­ecules linked by intramolecular N—H⋯O and O—H⋯O and intermolecular O—H⋯O hydrogen bonds into three‐dimensional networks.     

Naphthalene‐1,7‐diol

The asymmetric unit of the title compound, C₁₀H₈O₂, contains two planar symmetry‐independent mol­ecules linked by an O—H⋯O hydrogen bond. In the crystal structure, mol­ecules are linked into infinite chains of rings, formed by a combination of O—H⋯O and C—H⋯O hydrogen bonds, and additionally reinforced by π–π stacking inter­actions. Adjacent chains are connected by weak C—H⋯π inter­actions.     

1‐(1‐Amino‐4‐bromo‐9,10‐dioxo‐9,10‐dihydro­anthracen‐2‐ylcarbon­yl)‐1,3‐dicyclo­hexyl­urea

In the title compound, C₂₈H₃₀BrN₃O₄, the mol­ecules are linked by C—H⋯Br and N—H⋯O hydrogen bonds into one‐dimensional chains, which are arranged into a three‐dimensional network through a combination of C—H⋯O hydrogen bonds and two kinds of π–π inter­actions between the benzene rings of the anthraquinone units.