2,3,6,7‐Tetra­hydroxy‐9,10‐di­methyl‐9,10‐di­hydro‐9,10‐ethano­anthracene bis(1,4‐dioxane) solvate

2,3,6,7‐Tetra­hydroxy‐9,10‐di­methyl‐9,10‐di­hydro‐9,10‐ethano­anthracene crystallizes with 1,4‐dioxane to give a bis‐solvate, C₁₈H₁₈O₄·2C₄H₈O₂. The bis­(catechol) mol­ecule is located on a twofold axis and the two aromatic rings form a dihedral angle of 130.61 (4)°. Hydro­gen bonds are formed between the hydroxyl groups and either a neighbouring bis­(catechol) mol­ecule or the ether‐O atom of a dioxane mol­ecule.     

2‐(Hydro­xy­methyl)­pyridinium di­hydrogenphosphate

The title compound, C₆H₈NO⁺·H₂PO₄⁻, consists of 2‐(hy­droxy­methyl)­pyridinium and di­hydrogen­phosphate ions. The di­hydrogen­phosphate moieties are linked into chains by pairs of P—O—H⃛O—P hydrogen bonds. The 2‐(hydroxy­methyl)­pyridinium cations are connected to the di­hydrogen­phosphate units by O—H⃛O and N—H⃛O hydrogen bonds. Weak π–π interactions help to determine the interchain packing.     

N‐{4‐Bromo‐2‐[(3‐bromo‐1‐phenylsulfonyl‐1H‐indol‐2‐yl)methyl]‐5‐methoxyphenyl}acetamide

In the title compound, C₂₄H₂₀Br₂N₂O₄S, the indole ring system is planar and the S atom has a distorted tetrahedral configuration. The sulfonyl‐bound phenyl ring is orthogonal to the indole ring system and the conformation of the phenyl­sulfonyl substituent with respect to the indole moiety is influenced by intramolecular C—H⃛O hydrogen bonds involving the two sulfonyl O atoms. The mean plane through the acetyl­amido group makes a dihedral angle of 57.0 (1)° with the phenyl ring of the benzyl moiety. In the crystal, glide‐related mol­ecules are linked together by N—H⃛O hydrogen bonds and C—H⃛π interactions to form molecular chains, which extend through the crystal. Inversion‐related chains are interlinked by C—H⃛π interactions to form molecular layers parallel to the bc plane. These layers are interconnected through π–π interactions involving the five‐ and six‐membered rings of the indole moiety.     

The molecular and supramolecular structures of the isomeric compounds 5,7‐di­methoxy­imidazo­[1,2‐c]­pyrimidine and 7‐methoxy‐1‐methyl­imidazo­[1,2‐a]­pyrimidin‐5(1H)‐one

The supramolecular structures of the isomeric compounds 5,7‐di­methoxy­imidazo­[1,2‐c]­pyrimidine, C₈H₉N₃O₂, (I), and 7‐methoxy‐1‐methyl­imidazo­[1,2‐a]­pyrimidin‐5(1H)‐one, C₈H₉N₃O₂, (II), are determined by weak C—H⃛N and C—H⃛O hydrogen bonds in (I), which generate alternating linked centrosymmetric R(8) and R(10) rings that form a ribbon running parallel to the c axis, and by C—H⃛O bonds in (II), which link the mol­ecules into sheets comprising centro­symmetric R(10) and R(22) rings.     

2,7,12,17‐Tetraoxa‐3,4:5,6:13,14:15,16‐tetrabenzo­dispiro­[8.1.8.0]­nona­decane

The reaction of bi­phenyl‐2,2′‐diol with 1,1,2,2‐tetrakis­(bromo­methyl)­cyclo­propane leads to two products, namely a propellane‐type compound and a di­spiro‐type compound. The molecular structure of 4,5;6,7‐dibenzo‐3,8,12‐tri­oxa[8.3.1]­propellane has been determined previously by spectroscopic methods. The crystal structure of the di­spiro product, 2,7,12,17‐tetraoxa‐3,4:5,6:13,14:15,16‐tetrabenzodi­spiro[8.1.8.0]­nona­decane, C₃₁H₂₆O₄, revealed that the conformations of the nine‐membered heterocyclic rings are due to interactions between the π‐electron system of the bi­phenyl moiety and the lone electron pairs of the ether O atoms, the repulsion of the lone electron pairs of atoms O1⃛O2 and O3⃛O4, and steric interactions between H atoms in ortho positions. The conformations have C₁ symmetry and can be described approximately as twist‐boat.     

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.     

3,3′‐[o‐Phenyl­enebis­(methyl­eneoxy)]­bis(6‐chloro­flavone) and 3,3′‐propyl­ene­dioxy­bis­[6‐chloro‐2‐(2‐furyl)‐4H‐1‐benzopyran‐4‐one]

The title compound 3,3′‐[o‐phenyl­enebis­(methyl­eneoxy)]­bis(6‐chloro­flavone), C₃₈H₂₄Cl₂O₆, (I), crystallizes in the monoclinic space group C2/c, with the molecules lying across twofold rotation axes so that there is half a mol­ecule in the asymmetric unit, while the other title compound, 3,3′‐propyl­ene­dioxy­bis­[6‐chloro‐2‐(2‐furyl)‐4H‐1‐benzopyran‐4‐one], C₂₉H₁₈Cl₂O₈, (II), crystallizes in monoclinic space group P2₁/n with one mol­ecule in the asymmetric unit. In both compounds, the benzopyran moiety is nearly planar, with dihedral angles between the two fused rings of 1.43 (8)° in (I), and 2.54 (7) and 3.00 (6)° with respect to the benzopyran moieties in the two halves of (II). The furan rings are twisted by 8.3 (1) and 8.4 (1)° in the two halves of (II). In both compounds, the molecular structure is stabilized by intramolecular C—H⃛O hydrogen bonds, while the crystal packing is stabilized by C—H⃛Cl and C—H⃛O intermolecular hydrogen bonds in (I) and (II), respectively.     

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.     

Charge‐transfer complexes of 4‐(di­methyl­amino)­pyridine with 2,4‐, 3,4‐ and 3,5‐di­nitro­benzoic acid

In the three title crystal structures 4‐(di­methyl­amino)­pyridinium 2,4‐di­nitro­benzoate, (I), 4‐(di­methyl­amino)­pyri­dinium 3,4‐di­nitro­benzo­ate, (II), and 4‐(di­methyl­amino)pyri­din­ium 3,5‐di­nitro­benzo­ate, (III), all C₇H₁₁N₂⁺·C₇H₃N₂O₆^?, the ions are connected by an N—H?O hydrogen bond. Dihedral angles between the pyridine and phenyl rings are 69.9 (1), 26.7 (1) and 56.2 (1)° in (I), (II) and (III), respectively. Donor–acceptor π–π stacking is observed in (II) and (III), but not in (I).     

1,3‐Bis(4‐nitro­phenyl)­triazene

The structure of the title compound, C₁₂H₉N₅O₄, reveals an almost planar mol­ecule (r.m.s. deviation = 0.061 Å), in which the interplanar angle between the phenyl rings is 5.7 (1)° and the largest interplanar angle is that between the phenyl ring and the nitro group of one of the 4‐nitro­phenyl substituents [8.8 (3)°]. The observed mol­ecular conformation suggests a delocalization of π‐electrons extended over the diazo­amine group and the terminal aryl substituents. Intermolecular N—H⃛O interactions between the twofold screw‐related mol­ecules give rise to helical chains along the [010] direction. Intermolecular C—H⃛O interactions then generate sheets of mol­ecules in the (10) plane, and these sheets are held together by N⃛C and O⃛O π–π interactions.     

Two bis­(ammonium) 1,5‐naphthalene­disulfonate salts

The title compounds, bis­(ammonium) naphthalene‐1,5‐di­sul­fon­ate, 2NH₄⁺·C₁₀H₆O₆S₂²⁻, and bis­[1‐(hydroxy­methyl)‐3,5,7‐tri­aza‐1‐azoniatri­cyclo­[3.3.1.1^3,7]­decane] 1,5‐naphthalene­di­sul­fon­ate, 2C₇H₁₅N₄O⁺·C₁₀H₆O₆S₂²⁻, were prepared from the acid‐promoted reaction of hexa­methyl­enetetr­amine. In both structures, the di­sulfonate anion is positioned on an inversion center, with each sulfonate group contributing to the supramolecular assemblies via hydrogen bonds. The ammonium cations are linked to sulfonate groups by four distinct N⁺—H⃛⁻O—S contacts [N⃛O = 2.846 (2)–2.898 (2) Å and N—H⃛O = 160 (2)–175 (2)°], whereas the 1‐(hydroxy­methyl)‐3,5,7‐tri­aza‐1‐azoniatri­cyclo­[3.3.1.1^3,7]­decane cations form one O—H⃛⁻O—S [O⃛O = 2.628 (2) Å and O—H⃛O = 176°] and three C—H⃛⁻O—S [C⃛O = 3.359 (2)–3.380 (2) Å and C—H⃛O = 148–155°] interactions to neighboring sulfonate groups.     

N‐(o‐Chloro­phenyl)‐2,5‐di­methyl­pyrrole‐3‐carb­aldehyde

Crystal structure analysis of the title compound, C₁₃H₁₂ClNO, reveals three crystallographically independent mol­ecules in the asymmetric unit. The main conformational difference between these mol­ecules is the orientation of the phenyl rings with respect to the pyrrole rings. The coplanar arrangement of the aldehyde groups attached to the pyrrole rings influences the pyrrole‐ring geometry. The C2—C3 and N1—C5 bonds are noticeably longer than the C4—C5 and N1—C2 bonds. Two independent mol­ecules of the title compound form dimers via intermolecular C—H⃛O hydrogen bonds [D⃛A = 3.400 (3) Å and D—H⃛A = 157°]. The perpendicular orientation of the phenyl and pyrrole rings of one independent mol­ecule and its symmetry‐related mol­ecule allows C—H⃛π interactions, with an H⃛centroid distance of 2.85 Å and a C—H⃛π angle of 155°. The distances between the H atom and the pyrrole‐ring atoms indicate that the C—H bond points towards one of the bonds in the pyrrole ring.     

Hydro­gen bonding and π–π stacking in di­methyl­genistein

The title compound, 5‐hydroxy‐4′,7‐di­methoxy­isoflavone, C₁₇H₁₄O₅, is composed of a benzo­pyran­one moiety, a phenyl moiety and two methoxy groups. The benzo­pyran­one ring is not coplanar with the phenyl ring, the dihedral angle between them being 56.28 (3)°. The two methoxy groups are nearly coplanar with their corresponding rings, having C—C—O—C torsion angles of 2.9 (2) and 5.9 (2)°. The mol­ecules are linked by C—H·O hydrogen bonds into sheets containing classical centrosymmetric (8) rings. The sheets are further linked by aromatic π–π stacking interactions and C—H·O hydrogen bonds into a supramolecular structure.     

Three methoxy‐substituted diethyl 4‐­phenyl‐2,6‐di­methyl‐1,4‐di­hydro­pyridine‐3,5‐di­carboxyl­ate compounds

Diethyl 4‐(2,5‐di­methoxy­phenyl)‐2,6‐di­methyl‐1,4‐di­hydro­pyridine‐3,5‐di­carboxyl­ate, C₂₁H₂₇NO₆, (I), diethyl 4‐(3,4‐di­methoxy­phenyl)‐2,6‐di­methyl‐1,4‐di­hydro­pyridine‐3,5‐di­carboxyl­ate, C₂₁H₂₇NO₆, (II), and diethyl 2,6‐di­methyl‐4‐(3,4,5‐tri­methoxy­phenyl)‐1,4‐di­hydro­pyridine‐3,5‐di­carboxyl­ate, C₂₂H₂₉NO₇, (III), crystallize with hydrogen‐bonding networks involving the H atom bonded to the N atom of the 1,4‐di­hydro­pyridine ring and carbonyl O atoms in (I) and (II). Unusually, (III) shows O atoms of methoxy groups serving as hydrogen‐bond acceptors.     

1‐(2‐Hydro­xy‐4‐methoxy­phenyl)‐3‐(2,3,4‐tri­methoxy­phenyl)­prop‐2‐en‐1‐one

The title compound, C₁₉H₂₀O₆, crystallizes in the centrosymmetric space group P2₁/c with one mol­ecule in the asymmetric unit. The mol­ecule is approximately planar and the dihedral angle between the phenyl rings is 11.0 (1)°. The H atoms of the central propenone group are trans. There is an intramolecular O—H⃛O hydrogen bond and the mol­ecules are crosslinked by four intermolecular C—H⃛O hydrogen bonds, producing a three‐dimensional network.     

A one‐dimensional zigzag coordination polymer of di­aqua­(pyridine‐2,3‐di­carboxyl­ato)­cobalt(II)

The asymmetric unit of the title one‐dimensional coordination polymer, catena‐poly­[[μ‐pyridine‐2,3‐di­carb­oxyl­ato‐1κO:2κ²N,O′‐bis­[di­aqua­cobalt(II)]]‐μ‐pyridine‐2,3‐di­carboxyl­ato‐1κ²N,O:2κO′:1′κO′], [Co(C₇H₃NO₄)(H₂O)₂]_n, is composed of a cobalt(II) ion, a pyridine‐2,3‐di­carboxyl­ate dianion and two water mol­ecules. The polymer has a zigzag structure consisting of a chain of edge‐fused rings, and the polymer chains are linked by O—H⃛O hydrogen bonds into a three‐dimensional framework.     

t‐3‐Iso­propyl‐1‐methyl‐r‐2,c‐6‐di­phenyl­piperidin‐4‐one thio­semi­carbazone

The piperidine ring in the title compound, C₂₂H₂₈N₄S, exhibits a chair conformation. The thio­semicarbazone moiety adopts an extended conformation, and the planar phenyl rings are oriented equatorially with respect to the piperidine ring. Two intermol­ecular hydrogen bonds involving the S atom form molecular pairs, and the crystal structure is stabilized by weak C—H⃛π interactions in addition to van der Waals forces.     

9,10‐Di­methoxy‐4‐methyl‐1,2‐di­hydro‐1‐aza­anthracen‐2‐one (kalasin­amide), a new aza­anthracene alkaloid

A new aza­anthracene alkaloid, namely 9,10‐di­methoxy‐4‐methyl‐1,2‐di­hydro‐1‐aza­anthracen‐2‐one (kalasin­amide), C₁₆H₁₅NO₃, has been isolated from the stems of Polyal­thia suberosa collected in the northeastern part of Thailand. Each of the aromatic rings in the mol­ecule is planar within 0.021 (2) Å. Molecules are linked to form centrosymmetric dimers by N—H?O hydrogen bonds [N?O 2.941 (4) Å].     

Hydro­gen‐bond networks in tris(4‐hydroxy­phenyl)­methane and its 1:1 molecular complex with 4,4′‐bi­pyridine

In tris(4‐hydroxy­phenyl)­methane (or 4,4′,4′′‐methane­triyl­tri­phenol), C₁₉H₁₆O₃, mol­ecules are connected by O—H⃛O hydrogen bonds [O⃛O = 2.662 (2) and 2.648 (2) Å] into two‐dimensional square networks that are twofold interpenetrated. In tris(4‐hydroxy­phenyl)­methane–4,4′‐bi­pyridine (1/1), C₁₉H₁₆O₃·C₁₀H₈N₂, trisphenol mol­ecules form rectangular networks via O—H⃛O [O⃛O = 2.694 (3) Å] and C—H⃛O [C⃛O = 3.384 (3) Å] hydrogen bonds. Bi­pyridine mol­ecules hydrogen bonded to phenol moieties [O⃛N = 2.622 (3) and 2.764 (3) Å] fill the voids to complete the structure.     

A cis‐stilbene derivative

The title compound, 4′‐methoxy‐α,2,3′,4‐tetra­nitro­stilbene, C₁₅H₁₀N₄O₉, crystallizes in the centrosymmetric space group P2₁/c with one mol­ecule in the asymmetric unit. The phenyl rings are inclined to one another and form a dihedral angle of 57.4 (1)°. The size of this angle is a result of intermolecular C—H⃛O interactions involving the phenyl H atoms. The torsion angle between the phenyl rings, −7.5 (3)°, indicates a cis geometry between them. The methoxy group is almost coplanar with the phenyl ring, and the nitro groups are twisted with respect to the phenyl rings because of the short H⃛O contacts. The crystal packing is stabilized by C—H⃛O hydrogen bonds, and the intermolecular hydrogen bonds form a C(12) graph‐set chain running along the [010] direction.