Intermolecular interactions and ­molecular geometry in molecular complexes of N,N‐di­methyl­aniline: the 1:1 complex with 1,2,4,5‐tetra­cyano­benzene

The partner mol­ecules of N,N‐di­methyl­aniline–1,2,4,5‐tetra­cyano­benzene (1/1), C₈H₁₁N·C₁₀H₂N₄, are stacked alternately in infinite columns. The N atom of the N,N‐di­methyl­aniline mol­ecule has a partially tetrahedral character and the distance between neighbouring mol­ecules in the stack is relatively short on the side where the lone‐pair electrons of this atom are located. Molecular‐packing analysis of this and three other complexes of N,N‐di­methyl­aniline shows that there is a close relationship between the strength of the intermolecular interaction on this side and the tetrahedral character of the N atom.     

2,4‐Di­nitro­phenyl­hydrazones of 2,4‐di­hydroxy­benz­aldehyde, 2,4‐di­hydroxy­aceto­phenone and 2,4‐di­hydroxy­benzo­phenone

In 2,4‐di­hydroxy­benz­aldehyde 2,4‐di­nitro­phenyl­hydrazone N,N‐di­methyl­form­amide solvate {or 4‐[(2,4‐di­nitro­phenyl)­hydrazono­methyl]­benzene‐1,3‐diol N,N‐di­methyl­form­amide solvate}, C₁₃H₁₀N₄O₆·C₃H₇NO, (X), 2,4‐di­hydroxy­aceto­phenone 2,4‐di­nitro­phenyl­hydrazone N,N‐di­methyl­form­am­ide solvate (or 4‐{1‐[(2,4‐di­nitro­phenyl)hydrazono]ethyl}benzene‐1,3‐diol N,N‐di­methyl­form­amide solvate), C₁₄H₁₂N₄O₆·C₃H₇NO, (XI), and 2,4‐di­hydroxy­benzo­phenone 2,4‐di­nitro­phenyl­hydrazone N,N‐di­methyl­acet­amide solvate (or 4‐­{[(2,4‐di­nitro­phenyl)hydrazono]phenyl­methyl}benzene‐1,3‐diol N,N‐di­methyl­acet­amide solvate), C₁₉H₁₄N₄O₆·C₄H₉NO, (XII), the molecules all lack a center of symmetry, crystallize in centrosymmetric space groups and have been observed to exhibit non‐linear optical activity. In each case, the hydrazone skeleton is fairly planar, facilitated by the presence of two intramolecular hydrogen bonds and some partial N—N double‐bond character. Each molecule is hydrogen bonded to one solvent mol­ecule.     

6‐(3,4‐Di­fluoro­benzoyl)‐3‐[2‐(4‐pyridyl)­ethyl]‐1,3‐benzo­thia­zol‐2(3H)‐one

A new type of benzo­thia­zolinone derivative with potential pharmacological activity, viz. 6‐(3,4‐di­fluoro­benzoyl)‐3‐[2‐(4‐pyridyl)­ethyl]‐1,3‐benzo­thia­zol‐2(3H)‐one, C₂₁H₁₄F₂N₂O₂S, has been prepared and studied by NMR, IR and single‐crystal X‐ray diffraction techniques. The mol­ecule is not planar, the pyridine and di­fluoro­benzene moieties being located above and below the benzo­thia­zole ring system. The carbonyl O atoms are involved in an intramolecular hydrogen‐bond‐type interaction.     

The binary adduct of 3,6,9,16,19,22‐hexaazatricyclo[22.2.2.211,14]triaconta‐11,13,24,26(1),27,29‐hexaene and benzene‐1,2,4,5‐tetracarboxylic acid

The crystals of the title salt, 6,21‐di­aza‐3,9,18,24‐tetraazoniatri­cyclo­[22.2.2.2^11,14]­triaconta‐11,13,24,26(1),27,29‐hexaene benzene‐1,2,4,5‐tetra­carboxyl­ate(4?) hexahydrate, C₂₄H₄₂N₆⁴⁺·C₁₀H₂O₈^4?·6H₂O, are formed by the intermolecular interaction of a macrocyclic hex­amine with a mol­ecule of C₆H₂(COOH)₄ in aqueous solution. Both the cation and the anion are on inversion centres. Hydro­gen bonds are formed between the four ammonium cations in the hex­amine and the four carboxyl­ate anions in the aromatic acid. Stacks exist along the crystallographic a axis in the solid state. The water mol­ecules also take part in a hydrogen‐bonding network which joins these stacks together.     

Benzene‐1,2,4,5‐tetra­carboxyl­ic acid–trans‐cinnam­amide (1/2)

In the title adduct, C₁₀H₆O₈·2C₉H₉NO, benzene‐1,2,4,5‐tetra­car­box­ylic acid has a crystallographic twofold axis parallel to b and forms a flat zigzag chain along c linked by O— H?O cyclic hydrogen bonds with cinnam­amide mol­ecules.     

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.     

Hydrogen‐bonded one‐dimensional networks in 1:1 complexes of N,N′‐bis(2‐pyridyl)aryldiamines with anilic acid

The 1:1 complexes N,N′‐bis(2‐pyridyl)­benzene‐1,4‐di­amine–anilic acid (2,5‐di­hydroxy‐1,4‐benzo­quinone) (1/1), C₁₆H₁₄N₄·C₆H₄O₄, (I), and N,N′‐bis(2‐pyridyl)­bi­phenyl‐4,4′‐di­amine–anilic acid (1/1), C₂₂H₁₈N₄·C₆H₄O₄, (II), have been prepared and their solid‐state structures investigated. The component mol­ecules of these complexes are connected via conventional N—H?O and O—H?N hydrogen bonds, leading to the formation of an infinite one‐dimensional network generated by the cyclic motif R(9). The anilic acid molecules in both crystal structures lie around inversion centres and the observed bond lengths are typical for the neutral mol­ecule. Nevertheless, the pyridine C—N—C angles [120.9 (2) and 120.13 (17)° for complexes (I) and (II), respectively] point to a partial H‐atom transfer from anilic aicd to the bispyridyl­amine, and hence to H‐atom disorder in the OHN bridge. The bispyridyl­amine mol­ecules of (I) and (II) also lie around inversion centres and exhibit disorder of their central phenyl rings over two positions.     

(5S*,6R*)‐1,7‐Dioxa­di­spiro­[4.0.4.4]­tetra­decane‐2,8‐dione

The title compound, C₁₂H₁₆O₄, (I), was prepared by oxidation of (5S*,6R*)‐1,7‐di­oxa­di­spiro­[4.0.4.4]­tetra­decane‐2,8‐diol us­ing silver(I) carbonate and posesses a cis configuration of the two five‐membered‐ring lactones fused spiro to the six‐membered carbocycle, which has a chair conformation. It represents an exceptional structure for bis‐tetra­hydro­furan units, which are interesting building blocks in natural products. The synthesis, spectroscopic data and X‐ray structural analysis are described. The crystal contains discrete mol­ecules separated by normal van der Waals distances.     

The crystal packing of 4,7‐dichloro‐ and 4,7‐dibromobenzo[c]furazan 1‐oxide

The molecular structures of 4,7‐di­chloro­benzo­[c]­fur­azan 1‐­oxide, C₆H₂Cl₂N₂O₂, (I), and 4,7‐di­bromo­benzo­[c]­fur­azan 1‐oxide, C₆H₂Br₂N₂O₂, (II), are normal. Compound (I) occurs in two polymorphic forms. One polymorph contains one mol­ecule in the asymmetric unit, organized into two‐dimensional sheets involving intermolecular N?Cl and O?Cl inter­actions. The second polymorph has three mol­ecules in the asymmetric unit, organized into two crystallographically different two‐dimensional sheets with similar interactions. Compound (II) is isomorphous with the second polymorph of (I). The three two‐dimensional sheets in the two polymorphs comprise a set of three two‐dimensional polymorphic arrangements.     

Ribbons of hydrogen‐bonded rings in the 1:2 complex of pyromellitic acid and di­methyl sulfoxide

In the title complex, pyromellitic acid–di­methyl sulfoxide (1/­2), C₁₀H₆O₈·2C₂H₆OS, mol­ecules of pyromellitic acid (1,2,4,5‐benzene­tetra­car­box­ylic acid) and di­methyl sulfoxide, the latter being well ordered, are linked to each other by O—­H⃛O hydrogen bonds. The formula unit displays crystallographic inversion symmetry. The packing consists of ribbons of hydrogen‐bonded rings that can be described by graph set C(10)R(18).     

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.     

(E)‐(4‐Hydroxyphenyl)(4‐nitrophenyl)diazene, (E)‐(4‐methoxyphenyl)(4‐nitrophenyl)diazene and (E)‐[4‐(6‐bromohexyloxy)phenyl](4‐cyanophenyl)diazene

Syntheses and X‐ray structural investigations have been carried out for (E)‐(4‐hydroxy­phenyl)(4‐nitro­phenyl)­diazene, C₁₂H₉N₃O₃, (Ia), (E)‐(4‐methoxy­phenyl)(4‐nitro­phenyl)­diazene, C₁₃H₁₁N₃O₃, (IIIa), and (E)‐[4‐(6‐bromo­hexyl­oxy)­phenyl](4‐cyano­phenyl)­diazene, C₁₉H₂₀BrN₃O, (IIIc). In all of these compounds, the mol­ecules are almost planar and the azo­benzene core has a trans geometry. Compound (Ia) contains four and compound (IIIc) contains two independent mol­ecules in the asymmetric unit, both in space group P (No. 2). In compound (Ia), the independent mol­ecules are almost identical, whereas in crystal (IIIc), the two independent mol­ecules differ significantly due to different conformations of the alkyl tails. In the crystals of (Ia) and (IIIa), the mol­ecules are arranged in almost planar sheets. In the crystal of (IIIc), the mol­ecules are packed with a marked separation of the azo­benzene cores and alkyl tails, which is common for the solid crystalline precursors of mesogens.     

Rotenone α‐oxime

The structure determination of the title compound, rotenone α‐oxime [systematic name: 1,2,12,12a‐tetra­hydro‐8,9‐di­meth­oxy‐2‐(1‐methyl­ethenyl)‐[1]­benzo­py­rano­[3,4‐b]­furo­[2,3‐h][1]benzo­pyran‐6(6H)‐one oxime], C₂₃H₂₃NO₆, confirms that the mol­ecule has an approximately V‐shaped structure. One of the rings has a typical cyclo­hexene‐like monoplanar conformation and the central ring adopts a 1,2‐diplanar conformation.     

Polymeric aqua­(μ4‐di­hydrogen benzene‐1,2,4,5‐tetra­carboxylato)(1,10‐phen­anthroline)cobalt(II)

In the title compound, poly[[aqua(1,10‐phenanthroline)­cobalt(II)]‐μ₄‐di­hydrogen benzene‐1,2,4,5‐tetra­carboxyl­ato], [Co(C₁₀H₄O₈)(C₁₂H₈N₂)(H₂O)]_n, each cobalt(II) cation has an octahedral geometry completed by one aqua O atom, three carboxy O atoms belonging to three H₂TCB²⁻ anions (H₂TCB²⁻ is di­hydrogen ­benzene‐1,2,4,5‐tetra­carboxyl­ate) and two N atoms from a 1,10‐phenanthroline mol­ecule. In the asymmetric unit, there are two half H₂TCB²⁻ anions lying about independent inversion centres. The bridging H₂TCB²⁻ anions have two coordination modes, viz.μ₂‐H₂TCB²⁻ and μ₄‐H₂TCB²⁻, resulting in a two‐dimensional coordination polymer. Furthermore, a three‐dimensional network is formed by O_carboxy⋯O_carboxy hydrogen‐bond interactions, with H⋯A distances in the range 1.69–1.82 Å, and O_carboxy⋯O_water interactions, with H⋯A distances in the range 1.91–1.94 Å.     

Cone and 1,3‐alternate conformers of 1,3‐bis­(ethoxy­carbonyl­methoxy)‐2,4‐di­hydroxy­calix­[4]­arene and 1,2,3,4‐tetrakis­(ethoxy­carbonyl­methoxy)­calix­[4]­arene

The two title ethoxy­carbonyl­methoxy derivatives of calix­[4]­arene, namely diethyl 2,4‐di­hydroxy­calix­[4]­arene‐1,3‐diyldi(oxy­ace­tate), C₃₆H₃₆O₈, (I), and tetraethyl ­calix­[4]­arene‐1,2,3,4‐tetra­yltetra­(oxy­acetate), C₄₄H₄₈O₁₂, (II), form two different conformations, viz. a cone in (I), where intramol­ecular hydrogen bonds are formed through OH groups in a partially substituted calix­[4]­arene, and a 1,3‐alternate form of a completely substituted calix­[4]­arene in (II). A unique three‐dimensional array of mol­ecules exists in (II), with the channels extended along the entire crystal.     

trans‐Di­chloro‐cis‐bis(3,6‐di­methyl­carbazolyl)‐cis‐bis­(tetra­hydro­furan)­zirconium(IV) benzene sesquisolvate

In the title compound, [ZrCl₂(C₁₄H₁₂N)₂(C₄H₈O)₂]·1.5C₆H₆, the Zr atom is pseudo‐octahedral, with two Cl atoms in trans positions and two tetra­hydro­furan mol­ecules in cis positions. The two 3,6‐di­methyl­carbazolyl ligands are in cis positions and are canted with respect to one another. The two Zr—N distances are 2.1148 (18) and 2.1236 (18) Å, and the N—Zr—N angle is 95.08 (7)°. The title compound crystallizes as the benzene solvate, with one of the benzene mol­ecules positioned on an inversion center.     

Charge‐transfer complexes of N‐methyl‐and N‐ethyl­carbazole with 3,5‐di­nitro­benzo­nitrile

In the two title compounds, N‐methyl­carba­zole–3,5‐di­nitro­benzo­nitrile (1/1), C₁₃H₁₁N·C₇H₃N₃O₄, (I), and N‐ethyl­carba­zole–3,5‐di­nitro­benzo­nitrile (1/1), C₁₄H₁₃N·C₇H₃N₃O₄, (II), the donor and acceptor mol­ecules are stacked alternately to form one‐dimensional columns. In (I), the N‐methyl group of the donor is nearly eclipsed with respect to one of the nitro groups of the neighboring acceptor in a column, whereas the N‐ethyl group is anti with respect to the cyano group of the neighboring acceptor in (II).     

4‐Hydro­xy‐ONN‐azoxy­benzene

The oxidation of 4‐hydroxy­azo­benzene provided a mixture of two azoxy compounds, which were separated by column chromatography. The isomer with the higher melting point appeared to belong to the α (ONN) series, as determined by X‐ray diffraction. The mol­ecule, C₁₂H₁₀N₂O₂, is almost planar. The benzene rings are twisted by 11.7 (2) (substituted) and 4.1 (1)° (unsubstituted) with respect to the ONN plane. The mol­ecules are connected to one another by strong O—H?O hydrogen bonds forming chains extended along [001], which are bound by much weaker C—H?O hydrogen bonds forming layers in the bc plane.     

(Borohydrido)(18‐crown‐6)potassium and (borohydrido)(dibenzo‐18‐crown‐6)(tetra­hydro­furan)potassium

In the two compounds (borohydrido)(1,4,7,10,13,16‐hexa­oxacyclo­octa­decane‐κ⁶O)potassium, [K(BH₄)(C₁₂H₂₄O₆)], (I), and (borohydrido)(1,4,7,10,13,16‐hexa­oxa‐2,3:11,12‐di­benzo­cyclo­octa­deca‐2,11‐diene‐κ⁶O)(tetra­hydro­furan)­potassium, [K(BH₄)(C₄H₈O)(C₂₀H₂₄O₆)], (II), the K atom is bound to the six O atoms of the crown ether and to a tridentate borohydride group, with further coordination to a tetra­hydro­furan mol­ecule in (II). The alkali metal ion environment is thus distorted hexa­gonal–pyramidal in (I) and bipyramidal in (II).     

Supramolecular hydrogen‐bonded hexamers in two 5‐aryl‐3‐methyl‐1‐phenyl‐1,6,7,8‐tetra­hydro­pyrazolo­[3,4‐b][1,4]­diazepines

In both title compounds, i.e. 3‐methyl‐1,5‐di­phenyl‐1,6,7,8‐tetra­hydro­pyrazolo­[3,4‐b][1,4]­diazepine, C₁₉H₁₈N₄, (I), and 5‐(4‐chloro­phenyl)‐3‐methyl‐1‐phenyl‐1,6,7,8‐tetra­hydro­pyra­zolo­[3,4‐b][1,4]­diazepine, C₁₉H₁₇ClN₄, (II), an N—H?N hydrogen bond links six mol­ecules to form an R(30) ring. Compound (I) crystallizes in the R space group and (II) crystallizes in P with three mol­ecules in the asymmetric unit. The mol­ecule of (I) contains a disordered seven‐membered ring.