Di­aza­bi­cyclo­[2.2.2]­octane‐1,4‐diium dichromate

The title compound, (C₆H₁₄N₂)[Cr₂O₇], consists of a di­aza­bi­cyclo­[2.2.2]­octane‐1,4‐diium cation and a discrete dichromate anion, which are linked in the crystal by N—H⋯O hydrogen bonds. The cation is ordered and distorted, owing to the confinement and twist of the hydrogen bonds involved. Two CrO₄ tetrahedra are joined through a shared O atom to form the dichromate anion. Chiral supramolecular chains of the title compound are built up via N—H⋯O hydrogen bonds, and C—H⋯O interactions play subordinate roles in forming the structure.     

Benzo­[i]­naphtho­[c,d]­bi­cyclo­[5.4.1]dodecan‐12‐one

In the title compound, penta­cyclo­[11.8.1.1^3,11.0^7,23.0^15,20]­tricosa‐3,5,7,9,11(23),15,17,19‐octaen‐22‐one, C₂₃H₂₀O, the bi­cyclo­[5.4.1]­dodecan‐12‐one moiety takes a rigid conformation in which the seven‐ and eight‐membered rings take chair and boat–boat forms, respectively. The mol­ecule has a non‐crystallographic mirror symmetry perpendicular to the benzene and naphthalene planes.     

Two hydro­chlorides of 7‐methyl‐3,7,11,17‐tetra­aza­bi­cyclo­[11.3.1]­heptadeca‐1(17),13,15‐triene

The X‐ray structure determinations of the two title com­pounds, namely 7‐methyl‐7,17‐di­aza‐3,11‐diazo­niabi­cyclo[11.3.1]­hep­ta­deca‐1(17),13,15‐triene dichloride monohydrate, C₁₄H₂₆N₄²⁺·2Cl^?·H₂O, (I), and 7‐methyl‐17‐aza‐3,7,11‐triazo­niabi­cyclo­[11.3.1]­heptadeca‐1(17),13,15‐triene 2.826‐chloride 0.174‐nitrate, C₁₄H₂₇N₄³⁺·2.826Cl^?·0.174NO₃^?, (II), are re­ported. Protonation occurs at the secondary amine N atoms in (I) and at all three amine N atoms in (II) to which the Cl^? ions are linked via N—H?Cl hydrogen bonds. The macrocyclic hole is quite different in both structures, as is observed by comparing particularly the N3?N4 distances [2.976 (4) and 4.175 (4) Å for (I) and (II), respectively]. In (II), a Cl^? ion alternates with an NO₃^? ion in a disordered structure.     

6‐Di­methoxy­methyl‐1‐methoxy­carbonyl­bi­cyclo­[3.1.0]­hex‐2‐ene‐2‐carboxyl­ic acid

The title compound, C₁₂H₁₆O₆, prepared by a standard synthetic method, was determined by single‐crystal X‐ray crystallography to exist with a cyclo­propane ring fused to a cyclo­pentene ring. Comparison of the unit‐cell dimensions and space group of this material with those of a crystal of the same material prepared using a route involving pig liver esterase hydro­lysis shows them to be identical.     

(2RS)‐5,6:7,8‐Dibenzobi­cyclo­[2.2.2]­octan‐2‐ol

The racemic form of the title secondary monoalcohol, C₁₆H₁₄O, forms crystals in which the mol­ecules are linked into chains by hydrogen bonding. The chain architecture is unusual; adjacent mol­ecules are related pseudosymmetrically, by either a pseudo‐diad or a pseudo‐glide plane, while alternate mol­ecules are related exactly by a crystallographic glide plane.     

The 1:1 adduct of 5‐methylbenzene‐1,3‐diol (orcin) and 1,4‐di­aza­bicyclo­[2.2.2]­octane

In the title adduct, C₆H₁₂N₂·C₇H₈O₂, the orcin and 1,4‐di­aza­bi­cyclo­[2.2.2]­octane moieties are held together by O—H⋯N hydrogen bonds. One‐dimensional chiral hydrogen‐bonded chains are formed along the b axis. Neighbouring chains are held together principally by van der Waals interactions and are interrelated by translation, resulting in a chiral layer.     

Benzyl 5‐{2‐[2‐(diethoxy­phosphinoyl)­acetyl]‐3‐oxo‐7‐thia‐2,4‐di­aza­bi­cyclo­[3.3.0]­oct‐6‐yl}pentanoate,a novel biotin derivative

The title compound, C₂₃H₃₃N₂O₇PS, has its phospho­no­acetate carbonyl group rotated slightly out of the plane of the ureido ring, with a C—N—C—O torsion angle of ?6.9 (4)°. The sulfur‐containing ring has an envelope conformation, while the ureido ring is nearly planar.     

1,4,4‐Tri­methyl‐9‐phenyl‐8‐oxa‐9‐aza­bi­cyclo­[3.2.2]­non‐6‐en‐2‐one

The structure of the adduct of eucarvone with nitro­so­benzene, C₁₆H₁₉NO₂, is reported. The [3.2.2] bicyclic system corresponds to two seven‐membered rings in boat and distorted chair conformations and a six‐membered ring that adopts a distorted boat conformation. No conjugation is observed between the phenyl group and the N—O system. The packing is directed mainly by a C?O hydrogen bond, C—H?O‐(1 ? x, ?y, z) and by intermolecular C—H?π interactions.     

Bis­[μ‐2‐(1,4,7,10‐tetraoxa‐13‐aza­cyclo­pentadeca‐13‐yl)­cyclo­hepta‐2,4,6‐trien‐1‐one]­bis­[bis­(thio­cyanato)­barium(II)]

In the title complex, [Ba₂(NCS)₄(C₁₇H₂₅NO₅)₂], each Ba²⁺ cation is coordinated by one N atom, four O atoms of the macrocyclic unit, two N atoms of thio­cyanate unit and one O atom from each of the tropone units.     

Ferrocene­carboxyl­ic acid–1,4‐di­aza­bi­cyclo­[2.2.2]­octane (2/1): sheets built from O—H⃛N and C—H⃛O hydrogen bonds

In the title compound, 2[Fe(C₅H₅)(C₆H₅O₂)]·C₆H₁₂N₂, the molecular components are linked into finite three‐component aggregates by strong O—H?N hydrogen bonds [O?N 2.578 (4) and 2.604 (5) Å; O—H?N 170 (5) and 174 (6)°]; these aggregates are further linked by C—H?O hydrogen bonds [C?O 3.327 (5)–3.401 (5) Å; C—H?O 149–157°] into continuous sheets in the form of (6,3) nets.     

()‐5‐(4‐Methoxy­phenyl­amino­carbonyl)‐1‐aza­bi­cyclo­[3.3.0]octan‐2‐one benzene solvate

The title trans prolyl amide exists as a benzene solvate, C₁₅H₁₈N₂O₃·C₆H₆, with positional disorder of the prolyl ring. The molecular structure is influenced by a close intramolecular N—H⋯N contact that provides structural support for the intramolecular catalysis of peptidyl–prolyl cis–trans isomerization.     

5,6‐Di­phenyl­[1,3]­di­thiolo­[4,5‐b]di­thiine‐2‐thione

In the title compound, C₁₇H₁₀S₅, the dithiine ring adopts a boat conformation while the di­thiole ring has an envelope conformation. The phenyl groups are planar and make dihedral angles of 40.7 (2) and 59.8 (2)° with the best plane of the thiine ring. The shortest intermolecular S?S contact is 3.305 (2) Å.     

N‐(2‐Fluoro­ethyl)‐3β‐(4‐iodo­phenyl)‐8‐methyl‐8‐aza­bi­cyclo­[3.2.1]­octane‐2α‐carbox­amide: a new cocaine derivative with equatorially attached ligands

In the title compound, C₁₇H₂₂FIN₂O, both the amide and the iodo­phenyl substituents of the tropane ring lie in equatorial positions. The crystal packing is determined by N—H⋯O and C—H⋯F intermolecular hydrogen‐bonding interactions.     

5,8,11‐Trioxa‐2,14‐di­thia­bi­cyclo­[13.4.1]­icosa‐1(19),15,17‐trien‐20‐one

The title compound, C₁₅H₂₀O₄S₂, crystallizes in a chiral space group although it contains mirror symmetry. The tropone ring is inclined at an angle of 50.3 (1)° to the crown ether ring. The planarity of the tropone ring system itself is diminished by as much as 20.8 (4)°.     

(E,E)‐2,5‐Di­methoxy‐1,4‐bis­[2‐(3,4,5‐tri­methoxy­phenyl)­ethenyl]­benzene

In the title compound, C₃₀H₃₄O₈, molecular symmetry is coincident with crystallographic inversion symmetry. A three‐dimensional network is generated containing both C—H·π and C—H·n(O) interactions. A comparison of the geometry of this mol­ecule and the structure of a number of 2,4,6‐tri­methoxy‐substituted analogues is provided.     

20‐Di­cyano­methyl­ene‐5,8,11,14‐tetraoxa‐2,17‐di­thia­bi­cyclo­[16.4.1]­tricosa‐1(23),18,21‐triene and its mercury(II) dichloride complex

The structures of the title compound, C₂₀H₂₄N₂O₄S₂, and its mercury(II) dichloride complex, dichloro{20‐di­cyano­methyl­ene‐5,8,11,14‐tetraoxa‐2,17‐di­thia­bi­cyclo­[16.4.1]­tricosa‐1(23),18,­21‐tri­ene‐κ⁴O,κS¹⁷}mercury(II), [HgCl₂(C₂₀­H₂₄­N₂­O₄­S₂)], have been determined by X‐ray crystallographic analyses. The mercury(II) dichloride complex has two independent mol­ecules of [HgCl₂(C₂₀H₂₄N₂O₄S₂)] in the lattice. The mercury(II) ion has pentagonal bipyramidal coordination which involves one S atom, four O atoms and two Cl^? ions.     

Revisited crystal symmetry of the high‐spin form of the iron(II) spin‐crossover complex di­cyano­[2,13‐di­methyl‐6,9‐dioxa‐3,12,18‐tri­aza­bi­cyclo­[12.3.1]­octadeca‐1(18),2,12,14,16‐pentaene]­iron(II) monohydrate

The title iron(II) complex, [Fe(CN)₂(C₁₅H₂₃N₃O₂)]·H₂O, is of interest to the spin‐crossover community because of its unusual temperature‐dependent magnetic behaviour as well as its relatively high relaxation temperature for the light‐induced spin‐crossover phenomenon. Structural modifications are strongly suspected to cause the unusual thermal spin‐crossover features. Recently, the high‐spin crystal structure has been reported but with an inadequate space group. In the present paper, the crystal structure is corrected by a new investigation, and some consequences for the structure–property relationships of this complex are discussed. The Fe^II ion is seven‐coordinate and lies on a twofold axis.     

Di­spiro­[fluorene‐9,5′‐[1,2,3,4]­tetra­thia­ne‐6′,9′′‐fluorene]

The tetra­thia­ne ring of the title compound, C₂₆H₁₆S₄, has a chair conformation and the mol­ecule has approximate C₂ symmetry. Each of the two fluorene ring systems is virtually planar, with the ring planes intersecting at an angle of 67.58 (5)°. This novel compound has been formed as a side product from the treatment of 9H‐fluorene‐9‐thione with methyl N‐[(benzyl­idene)­phenyl]­glycinate in the presence of LiBr and 1,6‐di­aza­bi­cyclo­[5.4.0]­un­decane.     

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.     

4‐[3‐(3,4‐Di­methoxy­phenyl)­prop‐2‐enoyl]­phenyl methacryl­ate and 4‐[3‐(2‐bromo­phenyl)­prop‐2‐enoyl]­phenyl methacryl­ate

Chalcones (α,β‐unsaturated ketones) are effective antitumour agents. It has been proved that having halogen or methoxy groups substituted in various positions of the phenyl ring enhances the activity of chalcones many times. The title compounds, C₂₁H₂₀O₅ and C₁₉H₁₅BrO₃, respectively, were chosen for crystallographic study in order to determine their structures and conformations. In both compounds, the keto group is in the s‐cis conformation and is almost planar. There are weak intramolecular interactions in both structures.