Methyl 1‐(4‐chloro­benzyl)‐2‐(4‐methyl­piperazin‐1‐yl)‐1H‐benz­imidazole‐5‐carboxyl­ate hemihydrate

The title compound, C₂₁H₂₃ClN₄O₂·0.5H₂O, contains two independent mol­ecules in the asymmetric unit. In each mol­ecule the piperazine ring adopts a chair conformation; the deviations of the piperazine N atoms from the best plane through the remaining four C atoms are ?0.678 (3) and 0.662 (3) Å in mol­ecule A, and 0.687 (3) and ?0.700 (3) Å in mol­ecule B. The mol­ecules are linked by two hydrogen bonds of the O—H?N type involving the O atom of the water mol­ecule of crystallization.     

Chains of edge‐fused hydrogen‐bonded R33(22) rings in 5,3′‐dihydr­oxy‐3,6,7,4′,5′‐penta­methoxy­flavone

The title compound [systematic name: 5‐hydroxy‐2‐(3‐hydroxy‐4,5‐dimethoxy­phenyl)‐3,6,7‐trimethoxy‐4H‐chromen‐4‐one], C₂₀H₂₀O₉, was isolated from the seeds of Cleom viscosa Linn. Two independent mol­ecules (A and B) are present in the asymmetric unit with almost similar conformations. The dihedral angles between the fused chromene ring system and the benzene ring bonded to it in mol­ecules A and B are 4.2 (1) and 12.7 (1)°, respectively. The hydroxy O atoms are involved in intra­molecular hydrogen bonding. The mol­ecules are linked by C—H⋯O and O—H⋯O inter­actions into chains of edge‐fused R₃³(22) rings. Aromatic π–π and weak C—H⋯π(arene) inter­actions are also observed.     

9(R)‐[6(R)‐Hydroxy­methyl‐1‐oxa‐4‐thia­cyclo­hexan‐2‐yl]hypoxanthine–water (4/3), a nucleoside analogue

The title compound, 9(R)‐[6(R)‐hydroxy­methyl‐1‐oxa‐4‐thia­cyclo­hexan‐2‐yl]‐1,9‐di­hydro‐6H‐purin‐6‐one–water (4/3), C₁₀H₁₂N₄O₃S·0.75H₂O, crystallizes in the triclinic space group P1 with four mol­ecules in the asymmetric unit and 0.75 waters of hydration per mol­ecule. The structure was refined to an R value of 0.072 for 3382 observed reflections. The four crystallographically independent mol­ecules are designated A, B, C and D. All four oxa­thia­ne rings adopt the chair conformation and the purine bases are in an anti orientation with respect to the sugar moieties. Molecules A and D and mol­ecules C and B are base paired by a single hydrogen bond of the type N—H?N. These base pairs are again hydrogen bonded to their translated pairs in the direction of a cell diagonal.     

1‐Methyl‐5,6‐di­phenyl­pyrazine‐2(1H)‐thione

The title compound, C₁₇H₁₄N₂S, crystallizes in a triclinic unit cell, with two crystallographically independent mol­ecules in the asymmetric unit. The two independent mol­ecules pack in the same sense and form segregated layers along the c axis. The crystal is light‐stable and no dimers are formed under irradiation. The intermolecular distances between the potential reactive centers (the C‐3 and C‐5 ring positions) are 4.093 (4) and 5.643 (4) Å for mol­ecule A, and 4.081 (4) and 5.614 (4) Å for mol­ecule B.     

1,2,3‐Trimethoxy‐5,11‐dihydro­indolo[1,2‐b]isoquinoline‐5,11‐dione

The title compound, C₁₅H₁₉NO₅, crystallizes in the monoclinic space group P2₁/c with four mol­ecules in the asymmetric unit, which differ from each other in the orientation of their methoxy groups. Of the three methoxy groups in each molecule, one lies close to the plane of the mol­ecule and the other two have an out‐of‐plane conformation where they point in opposite directions. In the crystal structure, four different types of π‐stacks are observed and the mol­ecules pack in two different types of stacking sheets, with alternating mol­ecules A and B in one ribbon and alternating mol­ecules C and D in the other. The supramolecular structure is supported by C—H⋯O and π–π inter­actions.     

4‐Chloro­aceto­phenone [1‐(4‐methoxyphenyl)­ethyl­idene]­hydra­zone

The crystal structure of the title mixed azine, C₁₇H₁₇ClN₂O, contains four independent mol­ecules, A–D, and mol­ecule B is disordered. All four mol­ecules have an N—N gauche conformation, with C—N—N—C torsion angles of 136.5 (4), 137.0 (4), ?134.7 (4) and ?134.7 (4)°, respectively. The phenyl rings are also somewhat twisted with respect to the plane defined by C_ipso and the imine bond. On average, the combined effect of these twists results in an angle of 64.7° between the best planes of the two phenyl rings. Arene–arene double T‐contacts are the dominant intermolecular inter­action. The methoxy‐substituted phenyl ring of one azine mol­ecule interacts to form a T‐contact with the methoxy‐substituted phenyl ring of an adjacent mol­ecule and, similarly, two chloro‐substituted phenyl rings of neighboring mol­ecules interact to form another T‐contact. The only exception is for mol­ecule B, for which the disorder leads to the formation of T‐­contacts between methoxy‐ and chloro‐substituted phenyl rings. The prevailing structural motif of T‐contact formation between like‐substituted arene rings results in a highly dipole‐parallel‐aligned crystal structure.     

2,6‐Di­benzyl‐1,2,3,5,6,7‐hexa­hydro‐2,4,6,8‐tetra­aza‐s‐indacene and 2,6‐bis(4‐methoxy­benzyl)‐1,2,3,5,6,7‐hexa­hydro‐2,4,6,8‐tetra­aza‐s‐indacene

The title compounds, C₂₂H₂₂N₄ and C₂₄H₂₆N₄O₂ [alternative names: 2,6‐dibenzyl‐2,3,6,7‐tetrahydro‐1H,5H‐dipyrrolo[3,4‐b; 3′,4′‐e]pyrazine and 2,6‐bis(4‐methoxybenzyl)‐2,3,6,7‐tetrahydro‐1H,5H‐dipyrolo[3,4‐b;3′,4′‐e]pyrazine], two 1,2,3,5,6,7‐hexa­hydro‐2,4,6,8‐tetra­aza‐s‐indacene derivatives, are both centrosymmetric and have similar S‐shaped structures. In the former, there are two independent mol­ecules (A and B), both of which possess C_i symmetry. These two mol­ecules are arranged such that the benzene ring substituent of mol­ecule B is directed towards the plane of the benzene ring substituent of mol­ecule A, with a dihedral angle of 55.4 (2)° between their planes. The shortest C—H⋯C distance is, however, only 3.21 (1) Å. In both compounds, the benzene ring substituents are almost perpendicular to the plane of the central pyrazine ring, and the pyrrolidine rings have perfect envelope conformations. In the crystal structures of both compounds, the mol­ecules pack in a herring‐bone arrangement.     

Chloro­(μ‐6‐methyl­pyridine‐2‐carboxyl­ato)bis­(6‐methyl­pyridine‐2‐carboxyl­ato)triphenyl­chromium(III)­tin(IV) chloro­triphenyl­tin(IV)

The title compound, [CrSn(C₆H₅)₃(C₇H₆NO₂)₃Cl][Sn(C₆H₅)₃Cl(CH₄O)], was obtained from the reaction of Ph₃SnCl with the complex [Cr(C₇H₆NO₂)₃] in methanol. The structure contains [Ph₃SnCl(MeOH)] (A) and [Ph₃SnClCr(C₇H₆NO₂)₃] (B) mol­ecules. In mol­ecule A, the Sn atom of Ph₃SnCl is coordinated by one methanol mol­ecule. In mol­ecule B, the Sn atom of Ph₃SnCl is coordinated by one carboxyl­ate O atom of [Cr(C₇H₆NO₂)₃]. Mol­ecules A and B are connected through an O—H⋯O hydrogen bond between a carboxyl­ate O atom and the methanol OH group. Weak C—H⋯Cl inter­actions and O—H⋯O hydrogen bonds extend the components of (I) into a two‐dimensional network.     

4‐Methyl‐N‐[2‐(p‐tolylsulfanyl)phenyl]benzene­sulfonamide

The title compound, C₂₀H₁₉NO₂S₂, is formed by a palladium–copper‐catalyzed reaction between 4‐methyl‐N‐[2‐(prop‐2‐ynyl­sul­fanyl)­phenyl]­benzene­sul­fon­amide and p‐iodo­toluene. The mol­ecules contain three essentially planar parts, namely an amino­thio­phenol moiety (A), a toluene­sulfone moiety excluding the oxo ligands (B) and a tolyl group (C), approximately orthogonal to each other; the dihedral angles A/B, A/C and B/C are 111.6 (1), 89.3 (1) and 101.4 (1)°, respectively. Intermolecular N—H?O hydrogen bonds link the mol­ecules into infinite one‐dimensional chains.     

The methanol hemisolvate of amiloride hydrochloride

In the asymmetric unit of N-(3,5-di­amino-6-chloro­pyrazin-2-yl­carbonyl)-N-(di­amino­methyl­ene)­ammonium chloride methanol hemisolvate, C₆H₉ClN₇O⁺·Cl⁻·0.5CH₄O, there are two crystallographically different amiloride mol­ecules. Crystallographically identical amiloride mol­ecules are stacked one above the other, alternately rotated by 180°. These stacks are arranged parallel to each other, forming layer A. The least-squares plane of the non-H atoms of the other mol­ecules lying in layer B is tilted against the corresponding plane of the mol­ecules in layer A by an angle of 79.89 (3)°. The methanol mol­ecules and Cl⁻ anions are located between these layers, although the methanol mol­ecules are closer to layer A.     

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.     

6a,6b,12a,12b‐Tetra­hydro­cyclo­octa­[3,4]­cyclo­buta­[1,2][8]­annulene

The cis,syn,cis‐tricyclic [2+2]‐dimer of cyclo­octatetraene, C₁₆H₁₆, crystallizes in space group Pca2₁ with two mol­ecules in the asymmetric unit. An extensive network of weak C—H⋯π(Czdbnd;C) interactions between the two independent mol­ecules, A and B, as well as A⋯A and B⋯B interactions, are observed in the supramolecular assembly. The C—H groups point more towards one C atom than to the centre of the Czdbnd;C bond. Notable among the interactions are bifurcated (cyclo­butane)C—H⋯Czdbnd;C contacts that span transannularly the eight‐membered ring.     

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.     

17α,21‐Di­hydroxy‐16β‐methylpregna‐1,4‐diene‐3,11,20‐trione (meprednisone)

The title compound, C₂₂H₂₈O₅, is a commercial therapeutic agent of the steroid class. Both independent mol­ecules in the asymmetric unit have six‐membered A rings that are planar, while the B and C rings adopt normal chair conformations. The five‐membered D ring is in a 13β,14α‐half‐chair con­formation, and the B/C and C/D ring junctions are in trans positions. Cohesion in the crystal is provided by O—H⃛O hydrogen bonds, which generate chains of mol­ecules that are organized in a plane that lies along the crystallographic b axis.     

Verticine ethanol hydrate (2/1/1)

The two symmetry‐independent mol­ecules of the title compound, cevane‐3β,6α,20‐triol ethanol hydrate (2/1/1), 2C₂₇H₄₅NO₃·C₂H₆O·H₂O, have the same stereochemical assignments. The six‐membered rings A, B, E and F are in the chair conformation, while ring D is in a boat conformation. The ring fusions are A/Btrans, B/Ctrans, C/Dcis, D/Etrans and E/Ftrans. The verticine mol­ecules are bridged by water and ethanol mol­ecules via hydrogen bonds to form two‐dimensional layers, and the crystal structure is built up by stacking of these layers.     

A simple compound with an ­unexpectedly complex structure: 4‐pyridone 6/5‐hydrate

The crystal structure of the title compound, C₅H₅NO·H₂O, contains five independent mol­ecules of pyridone and six independent water mol­ecules. The space group is P2₁, but four of the pyridones and four waters correspond closely to P2₁/n. The packing involves two layers; one consists of head‐to‐tail chains of pyridone mol­ecules 1–4 linked by N—H?O hydrogen bonds, and a second layer involves all the waters and the fifth pyridone. The layers are linked by hydrogen bonds from water to pyridone oxy­gen. The four water O atoms that accept only one classical hydrogen bond have their environment completed by C—H?O interactions.     

Crystal engineering with heteroboranes. II. 1,2‐Di­carboxy‐1,2‐dicarba‐closo‐dodecaborane(12) ethanol hemisolvate

The title compound, 1,2‐(COOH)₂‐1,2‐closo‐C₂B₁₀H₁₀·0.5C₂H₆O or C₄H₁₂B₁₀O₄·0.5C₂H₆O, forms a tetramer by incorporating ethanol (solvent) mol­ecules through hydrogen bonding. Two eight‐membered rings [graph set R(8)] are formed by hydrogen bonding between two carboxyl­ic acid groups, whereas two ten‐membered rings [R(10)] are formed by hydrogen bonding between two carboxyl­ic acid groups and the OH group of an ethanol mol­ecule (solvent). Two crystallographically independent tetramers are present in the crystal 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.     

Hydrogen bonding in C-methylated nitroanilines: three triclinic examples with Z′ = 2 or 4

4-Methyl-2-nitro­aniline, (I), C₇H₈N₂O₂, crystallizes with two mol­ecules in the asymmetric unit. The mol­ecules both form intramolecular N—H⃛O hydrogen bonds and they are linked into hydrogen-bonded C₂²(12) chains in which the two independent mol­ecules alternate. 4,5-Di­methyl-2-nitro­aniline, (II), C₈H₁₀N₂O₂, also has Z′ = 2 and the two independent mol­ecules each form hydrogen-bonded C(6) chains. In 4-­methyl-3-nitro­aniline, (III), C₇H₈N₂O₂, there are four mol­ecules in the asymmetric unit. Molecules of two of these types are linked by N—H⃛O hydrogen bonds into molecular ladders containing R₄³(18) rings and the other two types independently form single C(7) chains.     

Non‐merohedrally twinned crystals of N,N′‐bis(3‐methyl­phenyl)‐N,N′‐di­phenyl‐1,1′‐bi­phenyl‐4,4′‐di­amine: an excellent tri­phenyl­amine‐based hole transporter

N,N′‐Bis(3‐methyl­phenyl)‐N,N′‐di­phenyl‐1,1′‐bi­phenyl‐4,4′‐di­amine (TPD), C₃₈H₃₂N₂, crystallizes in the monoclinic space group P2₁ with a pseudo‐orthogonal lattice, rather than the previously reported orthorhombic space group P2₁2₁2₁ [Kennedy, Smith, Tackley, David, Shankland, Brown & Teat (2002). J. Mater. Chem. 12 , 168–172]. The asymmetric unit consists of two independent mol­ecules, A and B, which are arranged along the [100] direction to form vertical layers of alternately stacked A and B mol­ecules. Molecule A shows a great deal of rotational movement in the four terminal aryl rings, resulting in two disordered tolyl groups split over two sites, while mol­ecule B exhibits an almost cis configuration of the two terminal tolyl groups with respect to these ring planes.