2‐(Pyrrolidin‐1‐yl)‐1,4‐naphtho­quinone and 2‐phenyl­sulfanyl‐3‐(pyrrolidin‐1‐yl)‐1,4‐naphtho­quinone

The structure of 2‐(pyrrolidin‐1‐yl)‐1,4‐naphtho­quinone, C₁₄H_12.95Cl_0.05NO₂, (I), is actually a 0.95:0.05 mixture including 2‐chloro‐3‐(pyrrolidin‐1‐yl)‐1,4‐naphtho­quinone as a minor impurity, but (I) was resolved as a single molecule containing a Cl atom with 5% occupancy at the 3‐position. Compound (I) was prepared from the fully chloro‐substituted analogue in an attempt to produce the disubstituted pyrrolidinyl derivative. 2‐Phenyl­sulfanyl‐3‐(pyrrolidin‐1‐yl)‐1,4‐naphtho­quinone, C₂₀H₁₇NO₂S, (II), was also prepared from 2‐chloro‐3‐(pyrrolidin‐1‐yl)‐1,4‐naphtho­quinone, using a strong exocyclic nucleophile. The structure of (II) differs from previous structures of 2,3‐di­chloro‐1,4‐naphtho­quinone and its derivatives in that the naphtho­quinone ring is non‐planar.     

3,4‐Di­hydro‐6‐methyl‐3‐β‐d‐ribo­furan­osyl‐4,5′‐cyclo‐9H‐imidazo[1,2‐a]­purin‐9‐one hydrate

In the title compound, C₁₃H₁₃N₅O₄·H₂O (4,5′‐cyclo­wyosine·H₂O), the cyclization forces a syn arrangement of the aglycon with respect to the sugar moiety. The ribo­furan­ose part of the mol­ecule displays a β‐d configuration with an envelope C1′‐endo pucker. The mol­ecules are arranged in columns along the short a axis and are linked to water mol­ecules through O—H?O and O—H?N hydrogen bonds.     

2‐Chloro‐3‐morpholino‐1,4‐naphtho­quinone

The structure of the title compound, C₁₄H₁₂ClNO₃, (I), comprises essentially planar mol­ecules stacked parallel to the a axis. C—H?O hydrogen‐bonding interactions exist to both naphtho­quinone O atoms and the Cl atom, but not to the morpholine O atom.     

Comparison of conventional and synchrotron X‐ray structure deter­minations of the adduct 1,2,4,5‐tetrahydroxybenzene–2,5‐dihydroxy‐1,4‐benzoquinone (1/1) and a conventional X‐ray structure determination of 1,2,4,5‐tetrahydroxybenzene monohydrate

The X‐ray structure of 1,2,4,5‐tetra­hydroxy­benzene (benzene‐1,2,4,5‐tetrol) monohydrate, C₆H₆O₄·H₂O, (I), reveals columns of 1,2,4,5‐tetra­hydroxy­benzene parallel to the b axis that are separated by 3.364 (12) and 3.453 (11) Å. Molecules in adjacent columns are tilted relative to each other by 27.78 (8)°. Water mol­ecules fill the channels between the columns and are involved in hydrogen‐bonding interactions with the 1,2,4,5‐tetra­hydroxy­benzene mol­ecules. The crystal structure of the adduct 1,2,4,5‐tetra­hydroxy­benzene–2,5‐di­hydroxy‐1,4‐benzo­quinone (1/1), C₆H₆O₄·C₆H₄O₄, (II), reveals alternating mol­ecules of 1,2,4,5‐tetra­hydroxy­benzene and 2,5‐di­hydroxy‐1,4‐benzo­quinone (both lying on inversion centers), and a zigzag hydrogen‐bonded network connecting mol­ecules in three dimensions. For compound (II), the conventional X‐ray determination, (IIa), is in very good agreement with the synchrotron X‐ray determination, (IIb). When differences in data collection temperatures are taken into account, even the displacement parameters are in very good agreement.     

A zwitterionic viologen disulfonate–hydroquinone charge‐transfer crystal: 2,2′‐(4,4′‐bipyridinium‐1,1′‐diyl)di(ethanesulfonate)–hydroquinone (1/2)

The structure of the title compound, C₁₄H₁₆N₂O₆S₂·2C₆H₆O₂, consists of 2,2′‐(4,4′‐bipyridinium‐1,1′‐diyl)di(ethanesulfon­ate) mol­ecules (with crystallographically imposed twofold symmetry) that are hydrogen bonded to each other, as well as to hydro­quinone mol­ecules, in a complex three‐dimensional motif. The orange color of the crystals is indicative of the donor–acceptor interaction between the electron‐rich hydro­quinone π‐donor and the electron‐deficient bipyridinium π‐acceptor. The dihedral angle between the bipyridyl planes is 38.31 (11)°. The distance from the centroid of one of the hydro­quinone mol­ecules to the center of the bipyridinium group is 3.653 (3) Å, which is within the range typically observed for molecular complexes exhibiting charge‐transfer characteristics.     

6‐Acetonyldi­hydro­avicine

The title compound, 1‐(5‐methyl‐5,6‐di­hydro­[1,3]­dioxolo­[4′,5′:4,5]­benzo­[c][1,5]­dioxolo­[4,5‐j]­phenanthridin‐6‐yl)­acetone, C₂₃H₁₉NO₅, isolated from the stem bark of Zanthoxy­lum rhoifolium, crystallizes as a racemate in space group P. The structure shows two aromatic ring systems, each terminated by a five‐membered dioxole ring, coupled by an N‐containing ring. The core of the mol­ecule is almost planar; the planes of the two ring systems form an angle of 18.42 (6)°. The packing shows the mol­ecules parallel to each other and about 3.5 Å apart with graphite‐type interactions. The N‐methyl and acetone groups, which are anti with respect to one another, lie out of the plane and pack in spaces between neighbouring mol­ecules.     

Inclusion compounds of 2,5‐di­phenyl­hydro­quinone

The crystal structures of three 1:2 inclusion compounds that consist of host mol­ecule 2,5‐di­phenyl­hydro­quinone (C₁₈H₁₄O₂) and the guest mol­ecules 2‐pyridone (C₅H₅NO), 1,3‐di­phenyl‐2‐propen‐1‐one (chalcone, C₁₅H₁₂O) and 1‐(4‐meth­oxy­phenyl)‐3‐phenyl‐2‐propen‐1‐one (4′‐methoxy­chal­cone, C₁₆H₁₄O₂) were determined in order to study the ability of guest mol­ecules in inclusion compounds to undergo photoreaction. All of the crystals were found to be photoresistant. The three inclusion compounds crystallize in triclinic space group . In each case, the host/guest ratio is 1:2, with the host mol­ecules occupying crystallographic centers of symmetry and the guest mol­ecules occupying general positions. The guest mol­ecules in each of the inclusion compounds are linked to the host mol­ecules by hydrogen bonds. In the inclusion compound where the guest mol­ecule is pyridone, the host mol­ecule is disordered so that the hydroxy groups are distributed between two different sites, with occupancies of 0.738 (3) and 0.262 (3). The pyridone mol­ecules form dimers via N—H⋯O hydrogen bonds.     

The dimer,trimer and 1,2,4‐tri­thiol­ane of adamantane­thione

The mol­ecules of di­spiro­[1,3‐dithietane‐2,2′:4,2′′‐diadamantane], C₂₀H₂₈S₂, have crystallographic C_i symmetry, as well as local D_2h symmetry, and a planar 1,3‐dithietane ring. The mol­ecules of tri­spiro­[1,3,5‐tri­thia­ne‐2,2′:4,2′′:6,2′′′‐triadamantane], C₃₀H₄₂S₃, have approximate C₂ symmetry and the 1,3,5‐tri­thia­ne ring has a twist–boat conformation. The C—S—C bond angles within the ring are about 8° larger than observed in most related 1,3,5‐tri­thia­ne structures. In di­spiro­[1,2,4‐tri­thiol­ane‐3,2′:5,2′′‐diadamantane], C₂₀H₂₈S₃, the mol­ecules have local C₂ symmetry and the 1,2,4‐tri­thiol­ane ring has a half‐chair conformation.     

2‐Chloro‐3‐(pyrrolidin‐1‐yl)‐1,4‐naphtho­quinone

The structure of the title compound, C₁₄H₁₂ClNO₂, (I), comprises essentially planar mol­ecules which crystallize in a monoclinic lattice. C—H?O interactions exist to both naphtho­quinone O atoms and the Cl atom.     

catena‐Poly[[[tetra­aqua­zinc(II)]‐μ‐4,4′‐bipyridine] bis­(4‐hydroxy­benzene­sulfonate) trihydrate]

In the title compound, {[Zn(C₁₀H₈N₂)(H₂O)₄](C₆H₅O₄S)₂·3H₂O}_n, the Zn atom, the bipyridine ligand and one of water mol­ecules are located on twofold rotation axes. The Zn atom is coordinated by four O atoms from four water mol­ecules and two N atoms from two 4,4′‐bipyridine mol­ecules in a distorted octa­hedral geometry. The Zn²⁺ ions are linked by the 4,4′‐bipyridine mol­ecules to form a one‐dimensional straight chain propagating along the c axis. The 4‐hydroxy­benzene­sulfonate counter‐ions are bridged by the solvent water mol­ecules through hydrogen bonds to generate a two‐dimensional layer featuring large pores. In the crystal packing, the intra­layer pores form one‐dimensional channels along the c axis, in which the one‐dimensional [Zn(C₁₀H₈N₂)(H₂O)₄]²⁺ chains are encapsulated. Electrostatic inter­actions between cations and anions and extensive hydrogen bonds result in a three‐dimensional supra­molecular structure.     

Di‐μ‐iodo‐bis{[1,1′‐methyl­enebis(3,5‐dimethyl‐1H‐pyrazole‐κN2)]copper(I)}

In the title compound, [Cu₂I₂(C₁₁H₁₆N₄)₂], each of the two crystallographically equivalent Cu atoms is tetrahedrally coordinated by two N atoms from one 1,1′‐methyl­ene­bis(3,5‐di­methyl‐1H‐pyrazole) ligand and two bridging iodide anions. The mol­ecule has a crystallographic center of symmetry located at the mid‐point of the Cu·Cu line. One H atom of the CH₂ group of the 1,1′‐methyl­ene­bis(3,5‐di­methyl‐1H‐pyrazole) ligand interacts with an iodide ion in an adjacent mol­ecule to afford pairwise intermolecular C—H·I contacts, thereby forming chains of mol­ecules running along the [101] direction.     

9‐(Tri­chloro­acetyl­imino)­acridine monohydrate

The title compound, alternatively called N‐acridin‐9(10H)‐yl­idene‐2,2,2‐tri­chloro­acet­amide mono­hydrate, C₁₅H₉Cl₃N₂O·H₂O, crystallizes in space group P2₁/c with Z = 4. The acridine moieties are arranged in layers, tilted at an angle of 15.20 (4)° relative to the ac plane, while adjacent mol­ecules pack in a head‐to‐tail manner. Acridine and water mol­ecules form columns along the b axis held in place by a network of hydrogen bonds, which is the major factor stabilizing the lattice. The acridine mol­ecule exhibits structural features of both the amino and imino forms, which could be due to the presence of the strong electronegative tri­chloro­acetyl substituent at the exocyclic N atom.     

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.     

11‐Hydro­xy‐3,3‐di­methyl‐7,12‐dioxo‐3,4,6,6a,7,12,12a,12b‐octa­hydro­benz­[a]­anthracen‐1‐yl acetate

The Diels–Alder reaction between 5‐hydroxy‐1,4‐naphtho­quinone and 5,5‐di­methyl‐3‐vinyl‐1,2‐cyclo­hexa­dienyl acetate by endo addition gives the title compound, C₂₂H₂₂O₅, in 68% yield. This racemic diastereoisomer has the opposite regiochemistry to ochromycinone analogues produced previously and may allow access to a new type of anticancer‐active saqua­yamycin analogue.     

The gossypol–cyclo­dodecanone (1/2) inclusion complex

Gossypol and cyclo­dodecanone crystallize at room temperature as an inclusion complex in a 1:2 molar ratio. This complex, viz. 1,1′,6,6′,7,7′‐hexa­hydroxy‐5,5′‐diiso­pro­pyl‐3,3′‐di­methyl‐2,2′‐bi­naphthalene‐8,8′‐di­carbox­aldehyde–cyclo­do­deca­none (1/2), C₃₀H₃₀O₈·2C₁₂H₂₂O, is unusual in that there is limited intermolecular hydrogen bonding within the structure. Each cyclo­dodecanone mol­ecule accepts a hydrogen bond from a gossypol mol­ecule, but there are no gossypol‐to‐gossypol hydrogen‐bond interactions. The gossypol mol­ecules form a framework structure enclosing channels, and the cyclo­dodecanone mol­ecules lie in these channels. In terms of the number of non‐H guest atoms, this is the largest gossypol inclusion complex reported to date.     

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.     

cis‐Verbenol

cis‐Verbenol (alternative name: 4,6,6‐tri­methyl­bi­cyclo­[3.1.1]­hept‐3‐en‐2‐ol), C₁₀H₁₆O, forms an orthorhombic P2₁2₁2₁ crystal that contains three mol­ecules per asymmetric unit. These three mol­ecules form hydrogen‐bonded helices parallel to the shortest axis of the lattice. The O?O distances associated with the hydrogen bonds are 2.760 (3), 2.760 (3) and 2.766 (3) Å.     

The 1:1 adduct of 2,5-dihydroxy-1,4-benzoquinone with 4,4′-bipyridine

2,5-Di­hydroxy-1,4-benzo­quinone (DHBQ) and 4,4′-bi­pyridine (BPY) crystallize in a 1:1 ratio as a neutral molecular adduct, C₆H₄O₄·C₁₀H₈N₂, in space group C2/c, with half of each mol­ecule in the asymmetric unit. The mol­ecules are linked by a strong O—H⃛N hydrogen bond [O⃛N 2.6323 (15) Å] and a weak C—H⃛O hydrogen bond [C⃛O 3.2082 (17) Å] to form infinite stacks of parallel one-dimensional hydrogen-bonded ribbons. The two rings of the bi­pyridine are twisted at 28.3° with respect to each other, and the benzo­quinone ring is inclined at an angle of 18.3° with respect to the plane of the neighbouring pyridine ring. The 4,4′-bi­pyridine mol­ecule lies on a twofold axis and the benzo­quinone mol­ecule lies across an inversion centre.     

A stacked pyrazolo[3,4‐d]pyrimidine‐based flexible molecule: the effect of a bulky benzyl group on intermolecular stacking in comparison with methyl and ethyl groups

In the crystal structure of 1,1′‐(1,3‐propane­diyl)­bis(5‐benzyl‐6‐methyl­sulfanyl‐4,5‐di­hydro‐1H‐pyrazolo­[3,4‐d]­pyrimidin‐4‐one), C₂₉H₂₈N₈O₂S₂, the pairs of pyrazolo­[3,4‐d]­pyrimidine rings stack as a result of intramolecular π–π interactions between the heterocyclic rings. The folded mol­ecules are further stacked in pairs, due to intermolecular aromatic π–π interactions and C—H?O hydrogen bonds.     

2,4,6‐Tri­methyl­phenol

Crystals of the title compound, C₉H₁₂O, were formed as an unexpected by‐product during the recrystallization of (2R,3R)‐α,α,α′,α′‐tetramesityl‐1,4‐dioxa­spiro­[4,5]­decane‐2,3‐di­methanol from hexane/ethyl acetate (7:3). Strong hydrogen bonds between hydroxide groups connect the mol­ecules around one set of four symmetry‐equivalent 2₁ axes.