rac‐(Z)‐2‐(2‐Thienylmethylene)‐1‐azabicyclo[2.2.2]octan‐3‐ol

The asymmetric unit of the racemic form of the title compound, C₁₂H₁₅NOS, contains four crystallographically independent molecules. The olefinic bond connecting the 2‐thienyl and 1‐azabicyclo[2.2.2]octan‐3‐ol moieties has Z geometry. Strong hydrogen bonding occurs in a directed co‐operative O—H...O—H...O—H...O—H R₄⁴(8) pattern that influences the conformation of the molecules. Co‐operative C—H...π interactions between thienyl rings are also present. The average dihedral angle between adjacent thienyl rings is 87.09 (4)°.     

Two two‐dimensional hydrogen‐bonded coordination networks: bis(3‐carboxybenzoato‐κO)bis(4‐methyl‐1H‐imidazole‐κN3)copper(II) and bis(3‐methylbenzoato‐κN)bis(4‐methyl‐1H‐imidazole‐κN3)copper(II) monohydrate

The title two‐dimensional hydrogen‐bonded coordination compounds, [Cu(C₈H₅O₄)₂(C₄H₆N₂)₂], (I), and [Cu(C₈H₇O₂)₂(C₄H₆N₂)₂]·H₂O, (II), have been synthesized and structurally characterized. The molecule of complex (I) lies across an inversion centre, and the Cu²⁺ ion is coordinated by two N atoms from two 4‐methyl‐1H‐imidazole (4‐MeIM) molecules and two O atoms from two 3‐carboxybenzoate (HBDC⁻) anions in a square‐planar geometry. Adjacent molecules are linked through intermolecular N—H...O and O—H...O hydrogen bonds into a two‐dimensional sheet with (4,4) topology. In the asymmetric part of the unit cell of (II) there are two symmetry‐independent molecules, in which each Cu²⁺ ion is also coordinated by two N atoms from two 4‐MeIM molecules and two O atoms from two 3‐methylbenzoate (3‐MeBC⁻) anions in a square‐planar coordination. Two neutral complex molecules are held together via N—H...O(carboxylate) hydrogen bonds to generate a dimeric pair, which is further linked via discrete water molecules into a two‐dimensional network with the Schläfli symbol (4³)₂(4⁶,6⁶,8³). In both compounds, as well as the strong intermolecular hydrogen bonds, π–π interactions also stabilize the crystal stacking.     

trans‐Diaquabis(3‐hydroxybenzoato‐κO1)bis(nicotinamide‐κN1)copper(II)

The title compound, [Cu(C₇H₅O₃)₂(C₆H₆N₂O)₂(H₂O)₂], is a two‐dimensional hydrogen‐bonded supramolecular complex. The Cu^II ion resides on a centre of symmetry and is in an octahedral coordination environment comprising two pyridine N atoms, two carboxylate O atoms and two O atoms from water molecules. Intermolecular N—H...O and O—H...O hydrogen bonds produce R₂²(4), R₂²(8) and R₂²(15) rings which lead to one‐dimensional polymeric chains. An extensive two‐dimensional network of N—H...O and O—H...O hydrogen bonds and C—H...π interactions are responsible for crystal stabilization.     

2‐Ethyl‐6‐methylpyridin‐3‐ol and its salt bis(2‐ethyl‐3‐hydroxy‐6‐methylpyridinium) succinate

The title compounds, C₈H₁₁NO, (I), and 2C₈H₁₂NO⁺·C₄H₄O₄²⁻, (II), both crystallize in the monoclinic space group P2₁/c. In the crystal structure of (I), intermolecular O—H...N hydrogen bonds combine the molecules into polymeric chains extending along the c axis. The chains are linked by C—H...π interactions between the methylene H atoms and the pyridine rings into polymeric layers parallel to the ac plane. In the crystal structure of (II), the succinate anion lies on an inversion centre. Its carboxylate groups interact with the 2‐ethyl‐3‐hydroxy‐6‐methylpyridinium cations via intermolecular N—H...O hydrogen bonds with the pyridine ring H atoms and O—H...O hydrogen bonds with the hydroxy H atoms to form polymeric chains, which extend along the [01] direction and comprise R₄⁴(18) hydrogen‐bonded ring motifs. These chains are linked to form a three‐dimensional network through nonclassical C—H...O hydrogen bonds between the pyridine ring H atoms and the hydroxy‐group O atoms of neighbouring cations. π–π interactions between the pyridine rings and C—H...π interactions between the methylene H atoms of the succinate anion and the pyridine rings are also present in this network.     

Diaquabis(4‐fluorobenzoato‐κO)bis(nicotinamide‐κN)cobalt(II)

The title compound, [Co(C₇H₄FO₂)₂(C₆H₆N₂O)₂(H₂O)₂], is a three‐dimensional hydrogen‐bonded supramolecular complex. The Co^II ion resides on a centre of symmetry and is in an octahedral coordination environment comprising two pyridyl N atoms, two carboxylate O atoms and two O atoms from water molecules. Intermolecular N—H...O and O—H...O hydrogen bonds produce R₃²(6), R₂²(12) and R₂²(16) rings, which lead to two‐dimensional chains. An extensive three‐dimensional network of C—H...F, N—H...O and O—H...O hydrogen bonds and π–π interactions are responsible for crystal stabilization.     

Bis{2‐[(phenylimino)ethyl]‐1H‐pyrrol‐1‐ido‐κ2N,N′}nickel(II): a supramolecular structure formed by C—H...π hydrogen bonds

In the title compound, [Ni(C₁₂H₁₁N₂)₂], the Ni^II cation lies on an inversion centre and has a square‐planar coordination geometry. This transition metal complex is composed of two deprotonated N,N′‐bidentate 2‐[(phenylimino)ethyl]‐1H‐pyrrol‐1‐ide ligands around a central Ni^II cation, with the pyrrolide rings and imine groups lying trans to each other. The Ni—N bond lengths range from 1.894 (3) to 1.939 (2) Å and the bite angle is 83.13 (11)°. The Ni—N(pyrrolide) bond is substantially shorter than the Ni—N(imino) bond. The planes of the phenyl rings make a dihedral angle of 78.79 (9)° with respect to the central NiN₄ plane. The molecules are linked into simple chains by an intermolecular C—H...π interaction involving a phenyl β‐C atom as donor. Intramolecular C—H...π interactions are also present.     

Supramolecular networks in (9‐fluoro‐4H‐chromeno[4,3‐c]isoxazol‐3‐yl)methanol and its 9‐chloro analogue at 100 K

The title compounds, (9‐fluoro‐4H‐chromeno[4,3‐c]isoxazol‐3‐yl)methanol, C₁₁H₈FNO₃, (I), and (9‐chloro‐4H‐chromeno[4,3‐c]isoxazol‐3‐yl)methanol, C₁₁H₈ClNO₃, (II), crystallize in the orthorhombic space group Pbca with Z′ = 1 and the triclinic space group P with Z′ = 6, respectively. The simple replacement of F by Cl in the main molecular scaffold of (I) and (II) results in significant differences in the intermolecular interaction patterns and a corresponding change in the point‐group symmetry from D_2h to C_i = S₂. These striking differences are manifested through the presence of C—H...F and the absence of O—H...O and C—H...O interactions in (I), and the absence of C—H...Cl and the presence of O—H...O and C—H...O interactions in (II). However, the geometry of the synthons formed by the O—H...N and O—H...X (X = F or Cl) interactions observed in the constitution of the supramolecular networks of both (I) and (II) remains similar. Also, C—H...O interactions are not preferred in the presence of F in (I), while they are much preferred in the presence of Cl in (II).     

Two 9‐[(E)‐nitrophenylvinyl]‐9H‐carbazoles

The crystal structures of 9‐[(E)‐(4‐nitrophenyl)vinyl]‐9H‐carbazole and 9‐[(E)‐(3‐nitrophenyl)vinyl]‐9H‐carbazole, both C₂₀H₁₄N₂O₂, are determined mainly by van der Waals forces and π–π interactions between the carbazole and benzene systems. However, the packing modes are different. In the 4‐nitro derivative, the molecules in the weakly bound stack are related by a unit‐cell translation, while in the 3‐nitro derivative there are centrosymmetric pairs of molecules joined by π–π interactions and also pairs of molecules, related by another centre of symmetry, connected by eight relatively short C—H...O interactions.     

Hydrogen‐bonded chains of rings in 1‐(4‐chloroanilinomethyl)‐5‐(4‐chlorophenyl)‐1,3,5‐triazinane‐2‐thione and hydrogen‐bonded sheets in 1‐anilinomethyl‐5‐phenyl‐1,3,5‐triazinane‐2‐thione

In 1‐(4‐chloroanilinomethyl)‐5‐(4‐chlorophenyl)‐1,3,5‐triazinane‐2‐thione, C₁₆H₁₆Cl₂N₄S, there are two independent molecules in the asymmetric unit which form inversion dimers via two weak N—H...S hydrogen bonds. The dimers are then linked into C(9)C(14) chains by a C—H...S hydrogen bond and a C—H...Cl contact. In 1‐(anilinomethyl)‐5‐phenyl‐1,3,5‐triazinane‐2‐thione, C₁₆H₁₈N₄S, molecules are linked into complex sheets via a combination of N—H...S and C—H...π hydrogen bonds.     

trans‐Bis(dimethyl sulfoxide‐κO)bis(3‐oxo‐3,4‐dihydroquinoxaline‐2‐carboxylato‐κ2N1,O2)copper(II)

The title compound, [Cu(C₉H₅N₂O₃)₂(C₂H₆OS)₂], consists of octahedrally coordinated Cu^II ions, with the 3‐oxo‐3,4‐dihydroquinoxaline‐2‐carboxylate ligands acting in a bidentate manner [Cu—O = 1.9116 (14) Å and Cu—N = 2.1191 (16) Å] and a dimethyl sulfoxide (DMSO) molecule coordinated axially via the O atom [Cu—O = 2.336 (5) and 2.418 (7) Å for the major and minor disorder components, respectively]. The whole DMSO molecule exhibits positional disorder [0.62 (1):0.38 (1)]. The octahedron around the Cu^II atom, which lies on an inversion centre, is elongated in the axial direction, exhibiting a Jahn–Teller effect. The ligand exhibits tautomerization by H‐atom transfer from the hydroxyl group at position 3 to the N atom at position 4 of the quinoxaline ring of the ligand. The complex molecules are linked through an intermolecular N—H...O hydrogen bond [N...O = 2.838 (2) Å] formed between the quinoxaline NH group and a carboxylate O atom, and by a weak intermolecular C—H...O hydrogen bond [3.392 (11) Å] formed between a carboxylate O atom and a methyl C atom of the DMSO ligand. There is a weak intramolecular C—H...O hydrogen bond [3.065 (3) Å] formed between a benzene CH group and a carboxylate O atom.     

A novel heterometallic dinuclear compound: rac‐pentaaqua‐1κ5O‐(μ‐2‐sulfidoacetato‐1:2κ3O:O′,S)bis(2‐sulfidoacetato‐2κ2O,S)manganese(II)tin(IV)

The title racemic heterometallic dinuclear compound, [MnSn(C₂H₂O₂S)₃(H₂O)₅], (I), contains one main group Sn^IV metal centre and one transition metal Mn^II centre, and, by design, links the Mn^II centre to the building unit of the (Δ/Λ) [SnL₃]²⁻ complex anion (L is the 2‐sulfidoacetate dianion). In this cluster, the Sn^IV centre of the (Δ/Λ) [SnL₃]²⁻ unit is coordinated by three O atoms and three S atoms from three L ligands to form an [SnO₃S₃] octahedral coordination environment. The Mn^II centre is in an [MnO₆] octahedral coordination environment, with five O atoms from five water molecules and the sixth from the μ₂‐L ligand of the (Δ/Λ) [SnL₃]²⁻ unit. Between adjacent dinuclear molecules, there are many hydrogen‐bond interactions of O—H...O, O—H...S, C—H...O and C—H...S types. Of these, eight pairs of O—H...O hydrogen bonds fuse all the dinuclear molecules into two‐dimensional supramolecular sheets along the bc plane. Adjacent supramolecular sheets are further connected through O—H...S hydrogen bonds to give a three‐dimensional supramolecular network.     

trans‐Diaquabis(nicotinamide‐κN)bis(salicylato‐κO)cobalt(II)

The title compound, [Co(C₇H₅O₃)₂(C₆H₆N₂O)₂(H₂O)₂], forms a three‐dimensional hydrogen‐bonded supramolecular structure. The Co^II ion is in an octahedral coordination environment comprising two pyridyl N atoms, two carboxylate O atoms and two O atoms from water molecules. Intermolecular N—H...O and O—H...O hydrogen bonds produce R₂²(8), R₂²(12) and R₂²(14) rings, which lead to two‐dimensional chains. An extensive three‐dimensional supramolecular network of C—H...O, N—H...O and O—H...O hydrogen bonds and C—H...π interactions is responsible for crystal structure stabilization. This study is an example of the construction of a supramolecular assembly based on hydrogen bonds in mixed‐ligand metal complexes.     

Hydrogen‐bonding patterns in 3‐alkyl‐3‐hydroxyindolin‐2‐ones

The molecules of racemic 3‐benzoylmethyl‐3‐hydroxyindolin‐2‐one, C₁₆H₁₃NO₃, (I), are linked by a combination of N—H...O and O—H...O hydrogen bonds into a chain of centrosymmetric edge‐fused R₂²(10) and R₄⁴(12) rings. Five monosubstituted analogues of (I), namely racemic 3‐hydroxy‐3‐[(4‐methylbenzoyl)methyl]indolin‐2‐one, C₁₇H₁₅NO₃, (II), racemic 3‐[(4‐fluorobenzoyl)methyl]‐3‐hydroxyindolin‐2‐one, C₁₆H₁₂FNO₃, (III), racemic 3‐[(4‐chlorobenzoyl)methyl]‐3‐hydroxyindolin‐2‐one, C₁₆H₁₂ClNO₃, (IV), racemic 3‐[(4‐bromobenzoyl)methyl]‐3‐hydroxyindolin‐2‐one, C₁₆H₁₂BrNO₃, (V), and racemic 3‐hydroxy‐3‐[(4‐nitrobenzoyl)methyl]indolin‐2‐one, C₁₆H₁₂N₂O₅, (VI), are isomorphous in space group P. In each of compounds (II)–(VI), a combination of N—H...O and O—H...O hydrogen bonds generates a chain of centrosymmetric edge‐fused R₂²(8) and R₂²(10) rings, and these chains are linked into sheets by an aromatic π–π stacking interaction. No two of the structures of (II)–(VI) exhibit the same combination of weak hydrogen bonds of C—H...O and C—H...π(arene) types. The molecules of racemic 3‐hydroxy‐3‐(2‐thienylcarbonylmethyl)indolin‐2‐one, C₁₄H₁₁NO₃S, (VII), form hydrogen‐bonded chains very similar to those in (II)–(VI), but here the sheet formation depends upon a weak π–π stacking interaction between thienyl rings. Comparisons are drawn between the crystal structures of compounds (I)–(VII) and those of some recently reported analogues having no aromatic group in the side chain.     

The diastereoisomers 2‐[(S/R)‐2‐chloro‐3‐quinolyl]‐2‐[(R)‐1‐(4‐methoxyphenyl)ethylamino]acetonitrile at 100 K

In the structures of the two enantiopure diastereoisomers of the title compound, C₂₀H₁₈ClN₃O, which crystallize in different space groups, the molecules are very similar as far as bond distances and angles are concerned, but more substantial differences are observed in some torsion angles. The crystal structures of both molecules can be described as zigzag layers along the c axis. The packing is stabilized by hydrogen‐bond interactions of N—H...O, C—H...Cl and C—H...π types for 2‐[(R)‐2‐chloro‐3‐quinolyl]‐2‐[(R)‐1‐(4‐methoxyphenyl)ethylamino]acetonitrile, and of N—H...N, C—H...O and C—H...π types for 2‐[(S)‐2‐chloro‐3‐quinolyl]‐2‐[(R)‐1‐(4‐methoxyphenyl)ethylamino]acetonitrile, resulting in the formation of two‐ and three‐dimensional networks.     

Tris(2,2′‐bipyridine)iron(II) bis(1,1,3,3‐tetracyano‐2‐ethoxypropenide) dihydrate: chiral hydrogen‐bonded frameworks interpenetrate in three dimensions

In the title compound, [Fe(C₁₀H₈N₂)₃](C₉H₅N₄O)₂·2H₂O, the chiral cations lie across twofold rotation axes in the space group C2/c. The anions and the water molecules are linked by two independent O—H...N hydrogen bonds to form C₂²(8) chains, and these chains are linked by the cations via C—H...N and C—H...O hydrogen bonds to form two interpenetrating three‐dimensional frameworks, each of which contains only one enantiomeric form of the chiral cation.     

A new coordination mode of 6‐methylnicotinic acid in trans‐tetraaquabis(6‐methylpyridine‐3‐carboxylato‐κO)cobalt(II) tetrahydrate

The title compound, [Co(C₇H₆NO₂)₂(H₂O)₄]·4H₂O, contains a Co^II ion lying on a crystallographic inversion centre. The Co^II ion is octahedrally coordinated by two 6‐methylpyridine‐3‐carboxylate ligands in axial positions [Co—O = 2.0621 (9) Å] and by four water molecules in the equatorial plane [Co—O = 2.1169 (9) and 2.1223 (11) Å]. There are also four uncoordinated water molecules. The 6‐methylpyridine‐3‐carboxylate ligands are bound to the Co^II ion in a monodentate manner through a carboxylate O atom. There is one strong intramolecular O—H...O hydrogen bond, and six strong intermolecular hydrogen bonds of type O—H...O and one of type O—H...N in the packing, resulting in a complex three‐dimensional supramolecular structure.     

Hydrogen‐bonded sheet structures in methyl 4‐(4‐chloroanilino)‐3‐nitrobenzoate and methyl 1‐benzyl‐2‐(4‐chlorophenyl)‐1H‐benzimidazole‐5‐carboxylate

In methyl 4‐(4‐chloroanilino)‐3‐nitrobenzoate, C₁₄H₁₁ClN₂O₄, (I), there is an intramolecular N—H...O hydrogen bond and the intramolecular distances provide evidence for electronic polarization of the o‐quinonoid type. The molecules are linked into sheets built from N—H...O, C—H...O and C—H...π(arene) hydrogen bonds, together with an aromatic π–π stacking interaction. The molecules of methyl 1‐benzyl‐2‐(4‐chlorophenyl)‐1H‐benzimidazole‐5‐carboxylate, C₂₂H₁₇ClN₂O₂, (II), are also linked into sheets, this time by a combination of C—H...π(arene) hydrogen bonds and aromatic π–π stacking interactions.     

(6‐Oxido‐2‐oxo‐1,2‐dihydropyrimidine‐5‐carboxylato‐κ2O5,O6)bis[2‐(2‐pyridyl)‐1H‐benzimidazole‐κ2N2,N3]manganese(II) monohydrate

In the title compound, [Mn(C₅H₂N₂O₄)(C₁₂H₉N₃)₂]·H₂O, the Mn^II centre is surrounded by three bidentate chelating ligands, namely, one 6‐oxido‐2‐oxo‐1,2‐dihydropyrimidine‐5‐carboxylate (or uracil‐5‐carboxylate, Huca²⁻) ligand [Mn—O = 2.136 (2) and 2.156 (3) Å] and two 2‐(2‐pyridyl)‐1H‐benzimidazole (Hpybim) ligands [Mn—N = 2.213 (3)–2.331 (3) Å], and it displays a severely distorted octahedral geometry, with cis angles ranging from 73.05 (10) to 105.77 (10)°. Intermolecular N—H...O hydrogen bonds both between the Hpybim and the Huca²⁻ ligands and between the Huca²⁻ ligands link the molecules into infinite chains. The lattice water molecule acts as a hydrogen‐bond donor to form double O...H—O—H...O hydrogen bonds with the Huca²⁻ O atoms, crosslinking the chains to afford an infinite two‐dimensional sheet; a third hydrogen bond (N—H...O) formed by the water molecule as a hydrogen‐bond acceptor and a Hpybim N atom further links these sheets to yield a three‐dimensional supramolecular framework. Possible partial π–π stacking interactions involving the Hpybim rings are also observed in the crystal structure.     

(E)‐4‐[(2‐Carbamoylhydrazinylidene)methyl]‐3‐hydroxy‐5‐hydroxymethyl‐2‐methylpyridin‐1‐ium nitrate

The title compound, C₉H₁₃N₄O₃⁺·NO₃⁻, is the first structurally characterized Schiff base derived from semicarbazide and pyridoxal. Unusually for an unsubstituted semicarbazone, the compound adopts a syn conformation, in which the carbonyl O atom is in a cis disposition relative to the azomethine N atom. This arrangement is supported by a pair of hydrogen bonds between the organic cation and the nitrate anion. The cation is essentially planar, with only a hydroxymethyl O atom deviating significantly from the mean plane of the remaining atoms (r.m.s. deviation of the remaining non‐H atoms = 0.01 Å). The molecules are linked into flat layers by N—H...O and C—H...O hydrogen bonds. O—H...O hydrogen bonds involving the hydroxymethyl group as a donor interconnect the layers into a three‐dimensional structure.     

2‐Cyano‐4‐iodoacetanilide: a hydrogen‐bonded chain of R22(12) and R22(14) rings

The molecules of 2‐cyano‐4‐iodoacetanilide, C₉H₇IN₂O, are linked by N—H...N and C—H...O hydrogen bonds into chains of alternating R₂²(12) and R₂²(14) rings.