catena‐Poly[bis[1‐chloromethyl‐1,4‐diazoniabicyclo[2.2.2]octane] [cadmium(II)‐tri‐μ‐chlorido‐[chloridocadmium(II)]‐di‐μ‐chlorido‐[chloridocadmium(II)]‐tri‐μ‐chlorido] tetrahydrate]

The title compound, {(C₇H₁₅N₂Cl)₂[Cd₃Cl₁₀]·4H₂O}_n, consists of 1‐chloromethyl‐1,4‐diazoniabicyclo[2.2.2]octane dications, one‐dimensional inorganic chains of {[Cd₃Cl₁₀]⁴⁻} anions and uncoordinated water molecules. Each of the two independent Cd^II ions, one with site symmetry 2/m and the other with site symmetry m, is octahedrally coordinated by chloride ions (two with site symmetry m and one with site symmetry 2), giving rise to novel polymeric zigzag chains of corner‐sharing Cd‐centred octahedra parallel to the c axis. The organic cations, bisected by mirror planes that contain the two N atoms, three methylene C atoms and the Cl atom, are ordered. Hydrogen bonds (O—H...Cl and O—H...O) between the water molecules (both with O atoms in a mirror plane) and the chloride anions of neighbouring chloridocadmate chains form a three‐dimensional supramolecular network.     

2,5‐Dimethyl‐6,7‐dihydrobenzo[h]pyrazolo[1,5‐a]quinazoline and 2‐tert‐butyl‐5‐methyl‐6,7‐dihydrobenzo[h]pyrazolo[1,5‐a]quinazoline

In both 2,5‐dimethyl‐6,7‐dihydrobenzo[h]pyrazolo[1,5‐a]quinazoline, C₁₆H₁₅N₃, (I), and 2‐tert‐butyl‐5‐methyl‐6,7‐dihydrobenzo[h]pyrazolo[1,5‐a]quinazoline, C₁₉H₂₁N₃, (II), which crystallizes with Z′ = 2 in the space group P, the non‐aromatic carbocyclic rings adopt screw‐boat conformations. The molecules of (I) are linked into chains of rings by a combination of C—H...N and C—H...π(arene) hydrogen bonds, while in (II) there are no hydrogen bonds of any kind.     

Two methyl 3‐(1H‐pyrazol‐4‐yl)octahydropyrrolo[3,4‐c]pyrrole‐1‐carboxylates form different hydrogen‐bonded sheets

In the molecules of both methyl (1RS,3SR,3aRS,6aSR)‐1‐methyl‐3‐(3‐methyl‐1‐phenyl‐1H‐pyrazol‐4‐yl)‐4,6‐dioxo‐5‐phenyloctahydropyrrolo[3,4‐c]pyrrole‐1‐carboxylate, C₂₅H₂₄N₄O₄, (I), and methyl (1RS,3SR,3aRS,6aSR)‐5‐(4‐chlorophenyl)‐1‐methyl‐3‐(3‐methyl‐1‐phenyl‐1H‐pyrazol‐4‐yl)‐4,6‐dioxooctahydropyrrolo[3,4‐c]pyrrole‐1‐carboxylate, C₂₅H₂₃ClN₄O₄, (II), the two rings of the pyrrolopyrrole fragment are both nonplanar, with conformations close to half‐chair forms. The overall conformations of the molecules of (I) and (II) are very similar, apart from the orientation of the ester function. The molecules of (I) are linked into sheets by a combination of an N—H...π(pyrrole) hydrogen bond and three independent C—H...O hydrogen bonds. The molecules of (II) are also linked into sheets, which are generated by a combination of an N—H...N hydrogen bond and two independent C—H...O hydrogen bonds, weakly augmented by a C—H...π(arene) hydrogen bond.     

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 similarly substituted benzo[h]pyrazolo[3,4‐b]quinoline‐5,6(10H)‐diones: supramolecular structures in two and three dimensions

The molecules of 8‐methyl‐7,10‐diphenyl‐5H‐benzo[h]pyrazolo[3,4‐b]quinoline‐5,6(10H)‐dione, C₂₇H₁₇N₃O₂, (I), are weakly linked into chains by a single C—H...O hydrogen bond, and these chains are linked into sheets by a π–π stacking interaction involving pyridyl and aryl rings. In 8‐methyl‐7‐(4‐methylphenyl)‐10‐phenyl‐5H‐benzo[h]pyrazolo[3,4‐b]quinoline‐5,6(10H)‐dione, C₂₈H₁₉N₃O₂, (II), the molecules are linked into a three‐dimensional framework structure by a combination of C—H...N, C—H...O and C—H...π(arene) hydrogen bonds, together with a π–π stacking interaction analogous to that in (I).     

Poly[di‐μ‐aqua‐[μ6‐N‐(4‐bromophenylsulfonyl)dithiocarbimato]dipotassium] and poly[di‐μ‐aqua‐[μ4‐N‐(4‐iodophenylsulfonyl)dithiocarbimato]dipotassium]

The rigid organic linkers N‐(4‐bromophenylsulfonyl)dithiocarbimate(2−) and N‐(4‐iodophenylsulfonyl)dithiocarbimate(2−) crystallize with two potassium cations and two water molecules in their asymmetric units, forming the title coordination polymers, [K₂(C₇H₄BrNO₂S₃)(H₂O)₂]_n and [K₂(C₇H₄INO₂S₃)(H₂O)₂]_n. The anions and the water molecules link the potassium cations into broad two‐dimensional networks, which are further linked by K...halide interactions.     

Layered poly[μ2‐aqua‐μ3‐dimethyl­formamide‐di‐μ3‐phenyl­phosphon­ato‐dipotassium]

The first structurally characterized alkali metal phospho­nate, the title compound, [K₂(C₆H₆O₃P)₂(C₃H₇NO)(H₂O)]_n, has a complex structure, with layers parallel to the crystallographic bc plane consisting of two crystallographically independent K atoms sandwiched between the three types of ligands present in the structure, viz. water molecules, dimethyl­formamide molecules and two crystallographically independent phenyl­phospho­nate ligands. Six O atoms coordinate to one K atom and seven to the other. The interlayer distance is 15.327 (4) Å. The K—O distances are in the range 2.739 (2)–2.932 (2) Å for the seven‐coordinate K atom and 2.650 (2)–2.821 (2) Å for the six‐coordinate K atom.     

2,2′‐Bi[benzo[b]thiophene]: an unexpected isolation of the benzo[b]thiophene dimer

The crystal structure of 2,2′‐bi[benzo[b]thiophene], C₁₆H₁₀S₂, at 173 K has triclinic (P) symmetry. It is of interest with respect to its apparent mode of synthesis, as it is a by‐product of a Stille cross‐coupling reaction in which it was not explictly detected by spectroscopic methods. It was upon crystal structure analysis of a specimen isolated from the mother liquor that this reaction was determined to give rise to the title compound, which is a dimer arising from the starting material. Two independent half‐molecules of this dimer comprise the asymmetric unit, and the full molecules are generated via inversion centers. Both molecules in the unit cell exhibit ring disorder, and they are essentially identical because of their rigidity and planarity.     

2‐[(E)‐(4‐Hydroxy‐3‐methoxybenzylidene)amino]‐N‐(2‐methylphenyl)‐4,5,6,7‐tetrahydro‐1‐benzothiophene‐3‐carboxamide

The title compound, C₂₄H₂₄N₂O₃S, exhibits antifungal and antibacterial properties. The compound crystallizes with two molecules in the asymmetric unit, with one molecule exhibiting `orientational disorder' in the crystal structure with respect to the cyclohexene ring. The o‐toluidine groups in both molecules are noncoplanar with the respective cyclohexene‐fused thiophene ring. In both molecules, there is an intramolecular N—H...N hydrogen bond forming a pseudo‐six‐membered ring which locks the molecular conformation and eliminates conformational flexibility. The crystal structure is stabilized by O—H...O hydrogen bonds; both molecules in the asymmetric unit form independent chains, each such chain consisting of alternating `ordered' and `disordered' molecules in the crystal lattice.     

Reactions between arylhydrazinium chlorides and 2‐chloroquinoline‐3‐carbaldehydes: molecular and supramolecular structures of a hydrazone,a 4,9‐dihydro‐1H‐pyrazolo[3,4‐b]quinoline and two 1H‐pyrazolo[3,4‐b]quinolines

Hydrazone derivatives exhibit a wide range of biological activities, while pyrazolo[3,4‐b]quinoline derivatives, on the other hand, exhibit both antimicrobial and antiviral activity, so that all new derivatives in these chemical classes are potentially of value. Dry grinding of a mixture of 2‐chloroquinoline‐3‐carbaldehyde and 4‐methylphenylhydrazinium chloride gives (E)‐1‐[(2‐chloroquinolin‐3‐yl)methylidene]‐2‐(4‐methylphenyl)hydrazine, C₁₇H₁₄ClN₃, (I), while the same regents in methanol in the presence of sodium cyanoborohydride give 1‐(4‐methylphenyl)‐4,9‐dihydro‐1H‐pyrazolo[3,4‐b]quinoline, C₁₇H₁₅N₃, (II). The reactions between phenylhydrazinium chloride and either 2‐chloroquinoline‐3‐carbaldehyde or 2‐chloro‐6‐methylquinoline‐3‐carbaldehyde give, respectively, 1‐phenyl‐1H‐pyrazolo[3,4‐b]quinoline, C₁₆H₁₁N₃, (III), which crystallizes in the space group Pbcn as a nonmerohedral twin having Z′ = 3, or 6‐methyl‐1‐phenyl‐1H‐pyrazolo[3,4‐b]quinoline, C₁₇H₁₃N₃, (IV), which crystallizes in the space group R. The molecules of compound (I) are linked into sheets by a combination of N—H…N and C—H…π(arene) hydrogen bonds, and the molecules of compound (II) are linked by a combination of N—H…N and C—H…π(arene) hydrogen bonds to form a chain of rings. In the structure of compound (III), one of the three independent molecules forms chains generated by C—H…π(arene) hydrogen bonds, with a second type of molecule linked to the chains by a second C—H…π(arene) hydrogen bond and the third type of molecule linked to the chain by multiple π–π stacking interactions. A single C—H…π(arene) hydrogen bond links the molecules of compound (IV) into cyclic centrosymmetric hexamers having (S₆) symmetry, which are themselves linked into a three‐dimensional array by π–π stacking interactions.     

Cs[Cl3F10]: A Propeller‐Shaped [Cl3F10]− Anion in a Peculiar A[5]B[5] Structure Type

Reaction of CsF with ClF₃ leads to Cs[Cl₃F₁₀]. It contains a molecular, propeller‐shaped [Cl₃F₁₀]^? anion with a central μ₃‐F atom and three T‐shaped ClF₃ molecules coordinated to it. This anion represents the first example of a heteropolyhalide anion of higher ClF₃ content than [ClF₄]^? and is the first Cl‐containing interhalogen species with a μ‐bridging F atom. The chemical bonds to the central μ₃‐F atom are highly ionic and quite weak as the bond lengths within the coordinating XF₃ units (X = Cl, and also calculated for Br, I) are almost unchanged in comparison to free XF₃ molecules. Cs[Cl₃F₁₀] crystallizes in a very rarely observed A^[5]B^[5] structure type, where cations and anions are each pseudohexagonally close packed, and reside, each with coordination number five, in the trigonal bipyramidal voids of the other.     

FeCl3‐Mediated Oxidative Spirocyclization of Difluorenylidene Diarylethanes Leading to Dispiro[fluorene‐9,5′‐indeno[2,1‐a]indene‐10′,9′′‐fluorene]s

A novel FeCl₃‐mediated oxidative spirocyclization for construction of a new class of di‐spirolinked π‐conjugated molecules, dispiro[fluorene‐9,5′‐indeno[2,1‐a]indene‐10′,9′′‐fluorene]s (DSFIIFs), has been reported. The combination of FeCl₃ with FeO(OH) triggered an unprecedented double one‐electron oxidation of difluorenylidene diarylethanes to afford the corresponding dispirocycles in high yields. The highest fluorescence quantum yield was up to 0.94 in solution. This protocol is also applicable to the synthesis of the non‐spirolinked dihydroindenoindenes.     

2,3,5,6‐Tetrakis[3,5‐bis(trifluoromethyl)phenoxy]‐2,5‐bis(dimethylamino)2,3,5,6‐tetrabora‐1,4‐dioxane diethyl ether 0.667‐solvate

The title compound, C₃₆H₂₆B₄F₂₄N₂O₆·0.667C₄H₁₀O, has centrosymmetric tetraboradioxane molecules, half each of three of these comprising the asymmetric unit together with a molecule of diethyl ether. Disorder affects most of the CF₃ groups and one ethyl group of the solvent molecule. The B₄O₂ rings are approximately planar and contain two B atoms with trigonal geometry and two with distorted tetrahedral geometry, the B—O bonds for the four‐coordinate B atoms being longer than those for the three‐coordinate B atoms. N—H...O hydrogen bonds link two of the crystallographically independent molecules together in chains, while the third molecule forms discrete trimolecular clusters with two solvent molecules via N—H...O hydrogen bonds. This is the first crystallographically characterized example of a tetrabora‐dioxane molecule containing both four‐ and three‐coordinate B atoms.     

Dispiro[indene‐2,5′‐indeno[2,1‐a]fluorene‐6′,2′′‐indene]‐1,1′′,3,3′′,11′,12′‐hexaone: a three‐dimensional hydrogen‐bonded framework

The title compound, C₃₆H₁₆O₆, (I), was obtained as a new and unexpected oxidation product of 1,2′‐biindene‐1′,3,3′(2H)‐trione. The molecules of (I) exhibit approximate, but noncrystallographic, twofold rotation symmetry and the central ring of the fused pentacyclic portion is distinctly puckered, with a conformation intermediate between half‐chair and screw‐boat. Six independent C—H...O hydrogen bonds link the molecules into a three‐dimensional framework structure of considerable complexity. Comparisons are drawn between the crystal structure of (I) and those of several simpler analogues, which show wide variation in their patterns of supramolecular aggregation.     

Exo conformers of N‐(pyridin‐2‐yl)‐ and N‐(pyridin‐3‐yl)norbornene‐5,6‐dicarboximide crystals

Two isomeric pyridine‐substituted norbornenedicarboximide derivatives, namely N‐(pyridin‐2‐yl)‐exo‐norbornene‐5,6‐dicarboximide, (I), and N‐(pyridin‐3‐yl)‐exo‐norbornene‐5,6‐dicarboximide, (II), both C₁₄H₁₂N₂O₄, have been crystallized and their structures unequivocally determined by single‐crystal X‐ray diffraction. The molecules consist of norbornene moieties fused to a dicarboximide ring substituted at the N atom by either pyridin‐2‐yl or pyridin‐3‐yl in an anti configuration with respect to the double bond, thus affording exo isomers. In both compounds, the asymmetric unit consists of two independent molecules (Z′ = 2). In compound (I), the pyridine rings of the two independent molecules adopt different conformations, i.e. syn and anti, with respect to the methylene bridge. The intermolecular contacts of (I) are dominated by C—H...O interactions. In contrast, in compound (II), the pyridine rings of both molecules have an anti conformation and the two independent molecules are linked by carbonyl–carbonyl interactions, as well as by C—H...O and C—H...N contacts.     

3‐Benzyl‐2‐(4‐fluorophenyl)‐1,3‐thiazolidin‐4‐one

The title compound, C₁₆H₁₄FNOS, crystallizes with Z′ = 2 in the space group P2₁/c. In one of the two independent molecules, the heterocyclic ring is effectively planar, but in the other molecule this ring adopts an envelope conformation. The molecules are weakly linked by two C—H...O hydrogen bonds to form C₂²(14) chains. Comparisons are made with some symmetrically substituted 2‐aryl‐3‐benzyl‐1,3‐thiazolidin‐4‐ones.     

{5′‐O‐[Bis(4‐methoxyphenyl)(phenyl)methyl]‐2′‐deoxy‐β‐D‐threopentofuranosyl}thymine ethyl acetate 0.25‐solvate

The title compound, C₃₁H₃₂N₂O₇·0.25C₄H₈O₂, is a key intermediate in the synthesis of [¹⁸F]fluorine‐labelled thymidine (¹⁸F‐FLT), which is the most widely used molecular imaging probe for positron emission tomography (PET). The crystallographic asymmetric unit contains two independent thymine molecules plus one partially occupied site for an ethyl acetate molecule. The two independent thymine molecules show similar geometrical features, except that the dimethoxytrityl groups adopt different orientations with respect to the remainder of the molecule. Each thymine base adopts an anti conformation with respect to the attached deoxyribose ring, and the deoxyribose rings show C3‐endo puckering. The conformation of the side chain at the C1 position of the deoxyribose ring is gauche+. Intermolecular N—H...O and O—H...O hydrogen bonds link the molecules into one‐dimensional chains.     

Poly[propane‐1,3‐diammonium [tetra‐μ3‐oxo‐hexaoxotrimolybdenum(VI)] dihydrate]

The crystal structure of the title compound, {(C₃H₁₂N₂)[Mo₃O₁₀]·2H₂O}_n, is composed of [Mo₃O₁₀]²⁻ anionic chains, propane‐1,3‐diammonium cations and solvent water molecules. The [Mo₃O₁₀]²⁻ chain is constructed from edge‐sharing MoO₆ octahedra. The protonated propane‐1,3‐diamine cations and solvent water molecules are located between the chains and are linked to the O atoms of the inorganic chains by hydrogen bonds.     

L‐Leucylglycine 0.67‐hydrate and [(4S)‐2,2‐dimethyl‐4‐(2‐methylpropyl)‐5‐oxoimidazolidin‐3‐ium‐1‐yl]acetate

Crystals of L‐leucylglycine (L‐Leu–Gly) 0.67‐hydrate, C₈H₁₆N₂O₃·0.67H₂O, (I), were obtained from an aqueous solution. There are three symmetrically independent dipeptide zwitterionic molecules in (I) and they are parallel to one another. The hydrogen‐bond network composed of carboxylate and amino groups and water molecules extends parallel to the ab plane. Hydrophilic regions composed of main chains and hydrophobic regions composed of the isobutyl groups of the leucyl residues are aligned alternately along the c axis. An imidazolidinone derivative was obtained from L‐Leu–Gly and acetone, viz. [(4S)‐2,2‐dimethyl‐4‐(2‐methylpropyl)‐5‐oxoimidazolidin‐3‐ium‐1‐yl]acetate, C₁₁H₂₀N₂O₃, (II), and was crystallized from a methanol–acetone solution of L‐Leu–Gly. The unit‐cell parameters coincide with those reported previously for L‐Leu–Gly dihydrate revealing that the previously reported values should be assigned to the structure of (II). One of the imidazolidine N atoms is protonated and the ring is nearly planar, except for the protonated N atom. Protonated N atoms and deprotonated carboxy groups of neighbouring molecules form hydrogen‐bonded chains. The ring carbonyl group is not involved in hydrogen bonding.     

2‐Bromo‐1,3‐bis[2‐(2‐naphthyl)vinyl]benzene benzene hemisolvate and 9‐bromodinaphth[1,2‐a:2′,1′‐j]anthracene

2‐Bromo‐1,3‐bis[2‐(2‐naphthyl)vinyl]benzene benzene hemisolvate, C₃₀H₂₁Br·0.5C₆H₆, (I), with two formula units in the asymmetric unit, exists in the crystal structure in a conformation in which the trans (2‐naphthyl)vinyl substituents on the central bromobenzene moiety appear as nearly fully extended `wings', while 9‐bromodinaphth[1,2‐a:2′,1′‐j]anthracene, C<sub>30</sub>H<sub>17</sub>Br, (II), adopts a highly nonplanar `manta‐ray' shape, with the H atoms in the interior of the molecule within van der Waals contact distances. The packing of the significantly twisted molecules of (I) generates large voids which are filled by benzene solvent molecules, while molecules of (II) stack compactly with all C—Br bonds parallel within the stack.