Two isomers of 2,4‐di­benzyl‐8‐azabicyclo­[3.2.1]­octan‐3‐ol

The crystal structures of the title compounds, 2α,4α‐di­benzyl‐3α‐tropanol (2α,4α‐di­benzyl‐8‐methyl‐8‐aza­bi­cyclo­[3.2.1]­octan‐3α‐ol), C₂₂H₂₇NO, (I), and 2α,4α‐di­benzyl‐3β‐tropanol (2α,4α‐di­benzyl‐8‐methyl‐8‐aza­bi­cyclo­[3.2.1]­octan‐3β‐ol), C₂₂H₂₇NO, (II), show that both compounds have a piperidine ring in a chair conformation and a pyrrolidine ring in an envelope conformation. Isomer (I) is asymmetric, the benzyl groups having different orientations, whereas isomer (II) is mirror symmetric, and the N and O atoms, the C atom attached to the hydroxy group, and the methyl C atom attached to the N atom lie on the mirror plane. In the crystal structures of both (I) and (II), the mol­ecules are linked together by intermolecular O—H⋯N hydrogen bonds to form chains that run parallel to the a direction in (I) and parallel to b in (II).     

Chloro(2‐{[5‐(2‐hydroxy­benzyl‐O)‐1,5‐di­aza‐1‐cyclo­octyl‐N,N′]­methyl}phenolato‐O)­cadmium(II)

The crystal structure of the title complex, [Cd(C₂₀H₂₅­N₂­O₂)­Cl], reveals a hydrogen‐bonded dimer composed of neutral molecules. The Cd^II center is five‐coordinated by two O atoms of the pendant arms, two nitro­gen donors of the 1,5‐di­aza­cyclo­octane ring and a chloride anion. The coordination geometry of the complex could be described as a distorted square pyramid. The 1,5‐di­aza­cyclo­octane backbone adopts a boat/chair configuration and the two phenol/phenolato groups have a dihedral angle of 101.3 (2)° between them. The coordinated phenolate and phenolic groups of inversion‐related mol­ecules form strong intermolecular O—H?O hydrogen bonds.     

Hydrogen bonding in nitroaniline analogues: hydrogen‐bonded sheets in 2‐amino‐4,6‐dimethoxy‐5‐nitropyrimidine and π‐stacked hydrogen‐bonded sheets in 4‐amino‐2,6‐dimethoxy‐5‐nitropyrimidine

In 2‐amino‐4,6‐di­methoxy‐5‐nitro­pyrimidine, C₆H₈N₄O₄, the mol­ecules are linked by one N—H⋯N and one N—H⋯O hydrogen bond to form sheets built from alternating R(8) and R(32) rings. In isomeric 4‐amino‐2,6‐di­methoxy‐5‐nitro­pyrimidine, C₆H₈N₄O₄, which crystallizes with Z′ = 2 in P, the two independent mol­ecules are linked into a dimer by two independent N—H⋯N hydrogen bonds. These dimers are linked into sheets by a combination of two‐centre C—H⋯O and three‐centre C—H⋯(O)₂ hydrogen bonds, and the sheets are further linked by two independent aromatic π–π‐stacking interactions to form a three‐dimensional structure.     

Supramolecular structures of 5‐[3‐(4‐methyl­phenyl)‐ and 5‐[3‐(4‐chloro­phenyl)‐2‐propenyl­idene]‐2,2‐di­methyl‐1,3‐dioxane‐4,6‐dione

2,2‐Di­methyl‐5‐[3‐(4‐methyl­phenyl)‐2‐propenyl­idene]‐1,3‐di­ox­ane‐4,6‐dione, C₁₆H₁₆O₄, crystallizes in the triclinic space group , with two mol­ecules in the asymmetric unit. These mol­ecules and a centrosymmetrically related pair, linked together by weak C—H?O hydrogen bonds, form a tetramer. 5‐[3‐(4‐Chloro­phenyl)‐2‐propenyl­idene]‐2,2‐di­methyl‐1,3‐dioxane‐4,6‐dione, C₁₅H₁₃ClO₄, also crystallizes in the triclinic space group , with one mol­ecule in the asymmetric unit. Centrosymmetrically related mol­ecules are linked together by weak C—H?O hydrogen bonds to form dimers which are further linked by yet another pair of centrosymmetrically related C—H?O hydrogen bonds to form a tube which runs parallel to the a axis.     

μ‐Cyano‐1:2κ2C:N‐tetracyano‐1κ4C‐(5‐methyl‐5‐nitro‐3,7‐diazanonane‐1,9‐diamine‐2κ4N1,3,7,9)‐nitrosyl‐1κN‐copper(II)iron(II) dihydrate

The title binuclear complex, [CuFe(CN)₅(C₈H₂₁N₅O₂)(NO)]·2H₂O or [CuFe(nelin)(CN)₅(NO)]·2H₂O (nelin is 5‐methyl‐5‐nitro‐3,7‐di­aza­nonane‐1,9‐di­amine) consists of discrete binuclear mixed‐metal species, with a Cu centre linked to an Fe centre through a cyano bridge, and two water mol­ecules of crystallization. In the complex, the Cu^II ion is coordinated by five N atoms and has a distorted square‐pyramidal geometry. The Fe^II centre is in a distorted octahedral environment.     

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 1:1 adduct of hexa­methyl­ene­tetramine (HMT) with racemic trans‐1,2‐cyclo­hexane­di­carboxylic acid (CDA)

Hexa­methyl­ene­tetramine and rac‐trans‐1,2‐cyclo­hexane­di­carboxylic acid crystallize in a 1:1 ratio as a neutral molecular adduct, C₆H₁₂N₄·C₈H₁₂O₄. Two di­carboxylic acid mol­ecules and two tetr­amine mol­ecules form a hydrogen‐bonded ring, in the shape of a rhombus, which lies on a crystallographic twofold axis bisecting the two diacid mol­ecules. The O—H⋯N hydrogen bonds have lengths 2.6808 (19) and 2.6518 (19) Å, and, in each ring, both acid mol­ecules have the same handedness.     

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].     

2,6‐Diiodo‐4‐nitrophenol, 2,6‐diiodo‐4‐nitrophenyl acetate and 2,6‐diiodo‐4‐nitroanisole: interplay of hydrogen bonds,iodo–nitro interactions and aromatic π–π‐stacking interactions to give supramolecular structures in one,two and three dimensions

In 2,6‐di­iodo‐4‐nitro­phenol, C₆H₃I₂NO₃, the mol­ecules are linked, by an O—H?O hydrogen bond and two iodo–nitro interactions, into sheets, which are further linked into a three‐dimensional framework by aromatic π–π‐stacking interactions. The mol­ecules of 2,6‐di­iodo‐4‐nitro­phenyl acetate, C₈H₅I₂NO₄, lie across a mirror plane in space group Pnma, with the acetyl group on the mirror, and they are linked by a single iodo–nitro interaction to form isolated sheets. The mol­ecules of 2,6‐di­iodo‐4‐nitro­anisole, C₇H₅I₂NO₃, are linked into isolated chains by a single two‐centre iodo–nitro interaction.     

Chloro­bis­(thio­urea‐κS)copper(I) bis(4,5‐di­aza­fluoren‐9‐one) mono­hydrate

The title compound, [CuCl(CH₄N₂S)₂]·2C₁₁H₆N₂O·H₂O, consists of mol­ecules of a Cu^I–thio­urea complex, free 4,5‐di­aza­fluoren‐9‐one (dafone) and crystalline water. The planar complex mol­ecule has trigonal coordination geometry around the Cu^I atom. The dafone and water mol­ecules, which are hydrogen bonded to the Cu^I complex, are approximately coplanar with this complex. The crystal displays a sheet structure and π–π stacking is observed between neighbouring sheets.     

Self‐assembly of 2‐pivaloyl‐6‐chloro­pterin

In the title compound, N‐(6‐chloro‐4‐oxo‐3,4‐di­hydro­pteridin‐2‐yl)­‐2,2‐di­methyl­propan­amide, C₁₁H₁₂ClN₅O₂, the rings in the pterin moiety are planar. The amide carbonyl O atom is in syn‐periplanar conformation while the C—N—C—C propanamide linkage is antiperiplanar. The N—H?N and N—H?O intermolecular hydrogen bonds transform the mol­ecules into infinite chains.     

The antifolate trimetrexate: ­observation of the enzyme‐binding conformation

The crystal structure of the title compound contains four 2,4‐di­amino‐5‐methyl‐6‐[(3,4,5‐tri­methoxy­anilino)­methyl]­quin­az­oline mol­ecules, two di­methyl sulfoxide mol­ecules and three water mol­ecules in the asymmetric unit, i.e. 4C₁₉H₂₃N₅O₃·2C₂H₆OS·3H₂O. All four quinazoline mol­ecules adopt trans,gauche conformations. An extensive hydrogen‐bond network involving N?N base‐pairing interactions, as well as the di­methyl sulfoxide and water mol­ecules, stabilizes the crystal structure.     

A uranyl ion complex of N‐methyl‐p‐tert‐butyl­dihomo­ammonio­calix­[4]­arene with di­aqua­di­pyridine­lithium as counter‐ion

The title complex, di­aqua­di­pyridine­lithium (N‐methyl‐p‐tert‐butyl­dihomo­ammonio­calix­[4]­arene‐κ⁴O)­dioxouranium(VI) tri­pyridine solvate monohydrate, [Li(C₅H₅N)₂(H₂O)₂][UO₂(C₄₆H₅₈NO₄)]·3C₅H₅N·H₂O, contains an `internal' tetraphenoxide‐coordinated uranyl complex of the macrocycle, in which the protonated N atom is involved in an intramolecular hydrogen bond with the uranyl oxo group located in the cavity. The Li⁺ ion is in a tetrahedral environment and its two water ligands are involved in hydrogen bonds with two phenoxide O atoms, two pyridine mol­ecules and one water mol­ecule. This arrangement is compared with those obtained previously for other homo­aza­calixarenes and also for homo­oxa­calixarenes in the presence of alkali metal hydro­xides.     

Diaquabis(1,3‐propanediamine‐κ2N,N′)nickel(II) bis(sulfanilate)

The title compound, [Ni(C₃H₁₀N₂)₂(H₂O)₂](C₆H₆NO₃S)₂, contains alternating layers of sulfanilate anions and di­aqua­bis(1,3‐propane­di­amine)­nickel(II) cations. The Ni atom lies on an inversion centre and is hexacoordinated by the 1,3‐propane­di­amine ligands, which function as N,N′‐bidentate ligands, and the water mol­ecules, which are in a trans arrangement. The sulfanilate anions are arranged in layers, with the sulfonate and amine groups directed towards opposite sides of the layer. The structure is stabilized by a network of hydrogen bonding between the O and N atoms of the sulfanilate anions, the water mol­ecules, and the N atoms of the 1,3‐propane­di­amine ligands.     

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.     

1,3‐Thia­zolidine derivatives from regioselective [2+3]‐cyclo­additions of azomethine yl­ides with thio­ketones

The title compounds, namely di­methyl (2RS)‐2,3‐di­phenyl‐1,3‐thia­zolidine‐5‐spiro‐2′‐adam­antane‐4,4‐di­carboxyl­ate methanol sol­vate, C₂₈H₃₁NO₄S·0.275CH₄O, and di­methyl (4RS)‐3,4‐di­phenyl‐1,3‐thia­zolidine‐5‐spiro‐9′‐(9′H‐fluorene)‐2,2‐di­car­box­ylate, C₃₁H₂₅NO₄S, were obtained from dipolar [2+3]‐cyclo­additions of an azo­methine yl­ide with adamantane­thione and thio­fluorenone, respectively. The structures show that the choice of thio­ketone affects the regioselectivity of the cyclo­addition. The asymmetric unit of the former structure contains two mol­ecules of the thia­zolidine derivative plus a site for a partial occupancy (55%) methanol mol­ecule. O—H⋯O and C—H⋯O interactions link two of each of these entities into closed centrosymmetric hexamers. The five‐membered ring in each structure has an envelope conformation.     

Di­propyl 3,6‐di­phenyl‐1,2‐di­hydro‐1,2,4,5‐tetrazine‐1,2‐di­carboxyl­ate

The title compound, C₂₂H₂₄N₄O₄, was prepared from propyl chloro­formate and 3,6‐di­phenyl‐1,2‐di­hydro‐s‐tetrazine. This reaction yields the title compound rather than di­propyl 3,6‐di­phenyl‐1,4‐di­hydro‐s‐tetrazine‐1,4‐di­carboxyl­ate. The 2,3‐di­aza­buta­diene group in the central six‐membered ring is not planar; the C=N double‐bond length is 1.285 (2) Å, and the average N—N single‐bond length is 1.401 (3) Å, indicating a lack of conjugation. The ring has a twist conformation, in which adjacent N atoms lie 0.3268 (17) Å from the plane of the ring. The mol­ecule has twofold crystallographic symmetry.     

5‐(2‐Pyridyl)‐1,3‐di­thia­ne‐2‐thione

The title compound, C₉H₉NS₃, crystallizes with two mol­ecules in the asymmetric unit. In both mol­ecules, the di­thia­ne‐2‐thione rings adopt a symmetric half‐boat conformation with the C atom opposite the C—S_thione bond out of the plane. The pyridine ring is in an equatorial position and is twisted out of the plane of the half‐boat by 82.7 (2) and 84.5 (2)° in the two mol­ecules, so that the N atom is trans to the axial C—H bond in both cases.     

Copper(II) and zinc(II) complexes of pyridine‐2,6‐di­carboxyl­ic acid

The title compounds, bis­(pyridine‐2,6‐di­carboxyl­ato‐N,O,O′)copper(II) monohydrate, [Cu(C₇H₄NO₄)₂]·H₂O, andbis(pyridine‐2,6‐dicarboxylato‐N,O,O′)zinc(II) trihydrate, [Zn(C₇H₄NO₄)₂]·3H₂O, have distorted octahedral geometries about the metal centres. Both metal ions are bonded to four O atoms and two pyridyl‐N atoms from the two terdentate ligand mol­ecules, which are nearly perpendicular to each other. The copper(II) complex has twofold crystallographic symmetry and contains two different ligand mol­ecules, one of which is neutral and another doubly ionized. In contrast, the zinc(II) complex contains two identical singly ionized ligand mol­ecules. Both crystal structures are stabilized by O—H?O intermolecular hydrogen bonds between the complex and the water mol­ecules.     

(±)‐6‐Benzyl‐3,3‐di­methyl­morpholine‐2,5‐dione and its 5‐mono­thio and 2,5‐di­thio derivatives

The morpholine ring of the title dione, C₁₃H₁₅NO₃, shows a boat conformation that is distorted towards a twist‐boat, with the boat ends being the two Csp³ atoms of the ring. The benzyl substituent is in the favoured `exo' position. In the mono­thione derivative, (±)‐6‐benzyl‐3,3‐di­methyl‐5‐thioxo­morpholin‐2‐one, C<sub>13</sub>H<sub>15</sub>NO<sub>2</sub>S, this ring has a much flatter conformation that is midway between a boat and an envelope, with the di­methyl end being almost planar. The orientation of the benzyl group is `endo'. The di­thione derivative, (±)‐6‐benzyl‐3,3‐di­methyl­morpholine‐2,5‐di­thione, C₁₃H₁₅N­OS₂, has two symmetry‐independent mol­ecules, which show different puckering of the morpholine ring. One mol­ecule has a flattened envelope conformation distorted towards a screw‐boat, while the conformation in the other mol­ecule is similar to that in the mono­thione derivative. Intermolecular hydrogen bonds link the mol­ecules in the three compounds, respectively, into centrosymmetric dimers, infinite chains, and dimers made up of one of each of the symmetry‐independent mol­ecules.