Bis{[phthalocyaninato(2–)]arsenic(III)} tetradecaiodotetraarsenic(III)

Crystals of the novel title arsenic(III) phthalocyanine complex, [As(C₃₂H₁₆N₈)]₂[As₄I₁₄] or [(AsPc)⁺]₂·[As₄I₁₄]²⁻, where Pc is phthalocyaninate(2−), have been obtained by the reaction of pure powdered As with phthalo­nitrile under a stream of iodine vapour at 493 K. The crystals are built up of separate but interacting [AsPc]⁺ cations and [As₄I₁₂]²⁻ anions. The As atom of the [AsPc]⁺ unit is bonded to the four iso­indole N atoms of the Pc macrocycle and lies 0.743 (2) Å out of the plane defined by these four N atoms. The anionic part of the complex consists of AsI₃ and [AsI₄]⁻ units joined together into an [As₄I₁₄]²⁻ anion. The arrangement of the oppositely charged moieties, [AsPc]⁺ and [As₄I₁₄]²⁻, in the crystal is determined mainly by ionic attraction and by donor–acceptor interactions between the [AsPc]⁺ and [As₄I₁₄]²⁻ ions.     

Indole- and carbazole-substituted pyridinium iodide salts: a rare case of conformational isomerism in crystals

A series of indole- and carbazole-substituted pyridinium iodide salts has been synthesized and characterized. X-ray analysis revealed that the iodide salt of the indole-substituted cation (E)-4-(1H-indol-3-yl­vinyl)-N-methyl­pyridinium (IMPE⁺), C₁₆H₁₅N₂⁺·I⁻, (I), has two polymorphic modifications, (Ia) and (Ib), and a hemihydrate structure, C₁₆H₁₅N₂⁺·I⁻·0.5H₂O, (II). Until now, only one crystal modi­fication has been identified for the (E)-4-(9-ethyl-9H-carbazol-3-yl­vinyl)-N-methyl­pyridinium (ECMPE⁺) iodide salt, C₂₂H₂₁N₂⁺·I⁻, (III). Crystals of (Ia) and (Ib) comprise stacks of antiparallel cations with iodide anions located in the channels between the stacks. Due to the presence of the water mol­ecules, the packing in (II) is quite different to that found in (Ia) and (Ib), and positional disorder involving a statistical superposition of two rotamers of IMPE⁺, with different orientations of the indole fragment, was found. Crystals of (III) contain two independent ECMPE⁺ rotamers with different orientations of their carbazole substituents. The cations are packed in stacks, with the iodide anions located in the channels between the stacks. In (III), the iodide was found to be disordered over two sites, with occupancies of 0.83 and 0.17.     

Bis{[phthalocyaninato(2–)]arsenic(III)} octa­iodo­diarsenic(III)

Crystals of the novel title arsenic(III)–phthalocyanine complex, [As(C₃₂H₁₆N₈)]₂[As₂I₈] or [AsPc]₂[As₂I₈], where Pc is the phthalocyaninate(2−) macrocycle, have been obtained from the reaction of pure powdered arsenic with phthalonitrile under oxidizing conditions (iodine vapour) at 463 K. The crystals are formed by separate but inter­acting [AsPc]⁺ cations and centrosymmetric [As₂I₈]²⁻ anions. The As atom of the [AsPc]⁺ ion is bonded to the four isoindole N atoms of the Pc macrocycle and lies 0.762 (1) Å out of their plane. The anionic part of the complex consists of two [AsI₄]⁻ units joined together into a centrosymmetric [As₂I₈]²⁻ counter‐ion. The arrangement of oppositely charged moieties, viz. [AsPc]⁺ and [As₂I₈]²⁻, in the crystal structure is determined mainly by their ionic attractions and by π–π inter­actions between the aromatic phthalocyaninate(2−) macrocycles.     

Hydrogen bonding in the inner-salt zwitterion and in two different charged forms of 5,6-bis(2-pyridyl)pyrazine-2,3-dicarboxylic acid

5,6-Bis(2-pyridyl)­pyrazine-2,3-di­carboxyl­ic acid exists as an inner-salt zwitterion, 3-carboxy-5-(2-pyridinio)-6-(2-pyridyl)­pyrazine-2-carboxyl­ate, (Ia), C₁₆H₁₀N₄O₄. The adjacent pyridine and pyridinium rings are almost coplanar due to the presence of an intramolecular hydrogen bond involving the pyridine N atom and the NH H atom of the pyridinium group. In the crystal of (Ia), symmetry-related mol­ecules are hydrogen bonded via the carboxyl­ic acid OH group and one of the carboxyl­ate O atoms to form a polymer, which exhibits a channel-type structure. In the HCl, HClO₄ and HPF₆ salts, 6-­carboxy-5-carboxyl­ato­pyrazine-2,3-diyldi-2-pyridinium chloride 2.25-hydrate, (II), C₁₆H₁₁N₄O₄⁺·Cl⁻·2.25H₂O, 6-­carboxy-5-carboxyl­ato­pyrazine-2,3-diyldi-2-pyridinium perchlor­ate trihydrate, (IIIa), C₁₆H₁₁N₄O₄⁺·ClO₄⁻·3H₂O, and 6-car­boxy-5-carboxyl­ato­pyrazine-2,3-diyldi-2-pyridinium hexa­fluoro­phosphate trihydrate, (IIIb), C₁₆H₁₁N₄O₄⁺·PF₆⁻·3H₂O, both pyridine rings are protonated. In the perchlorate form, and in the isomorphous hexa­fluoro­phosphate form, the mol­ecule possesses C₂ symmetry, with has a symmetrical intramolecular hydrogen bond involving the adjacent carboxyl­ate and carboxyl­ic acid substituents. In the crystals of the chloride and perchlorate (or hexa­fluoro­phosphate) salts, hydrogen-bonded polymers are formed which are three-dimensional and one-dimensional, respectively.     

l‐Methioninium chloride and l‐seleno­methioninium chloride at 103 K

The crystal structures of the title compounds, (S)‐1‐carboxy‐3‐(methyl­sulfanyl)­propanaminium chloride, C₅H₁₂NO₂S⁺·Cl⁻, and (S)‐1‐carboxy‐3‐(methyl­selanyl)­propanaminium chloride, C₅H₁₂NO₂Se⁺·Cl⁻, are isomorphous. The proton­ated l ‐methionine and l ‐seleno­methionine mol­ecules have almost identical conformations and create very similar contacts with the Cl⁻ anions in the crystal structures of both compounds. The amino acid cations and the Cl⁻ anions are linked viaN—H⋯Cl⁻ and O—H⋯Cl⁻ hydrogen bonds.     

Mono­alkyl­ated 4′‐aryl‐substituted terpyridines

1‐Methyl‐2‐[4‐phenyl‐6‐(pyridinium‐2‐yl)­pyridin‐2‐yl]­pyridinium diperchlorate, C₂₂H₁₉N₃²⁺·2ClO₄⁻, (I), and 2‐[4‐(methoxy­phenyl)‐2,2′‐bipyridin‐6‐yl]‐1‐methyl­pyridinium iodide, C₂₃H₂₀N₃O⁺·I⁻, (II), both crystallize in the monoclinic space group P2₁/c. In contrast with the monocharged mol­ecule of (II), the doubly charged mol­ecule of (I) contains an additional protonated pyridine ring. One of the two perchlorate counter‐anions of (I) interacts with the cation of (I) via an N—H⋯O hydrogen bond. In (II), two mol­ecules related by a centre of symmetry are connected by weak π–π interactions, forming dimers in the crystal structure.     

3,6-Bis(dimethylamino)-10-propylacridinium iodide

In the title compound, C₂₀H₂₆N₃⁺·I⁻, the acridinium moiety shows mirror symmetry about the central C—N vector. The fused tricyclic system is only approximately planar and the geometry is affected by the presence of both di­methyl­amino groups and the propyl substitution at the central N atom. The propyl chain adopts an extended trans conformation and the plane through the chain C atoms is perpendicular to the mean plane through the rings. The I⁻ ion is involved in short-range hydrogen-bonding interactions with two centrosymmetrically related cations via three activated acridinium C atoms. Stacks of acridinium cations propagate through the crystal along the c direction. The ring overlap is partial, but the di­methyl­amino groups also participate in the stacking.     

Dihydrobis(methylamine)borate triiodide

Both cation and anion in the title compound, C₂H₁₂BN₂⁺·I₃⁻, lie on a crystallographic mirror plane and are bound in the lattice by N—H⋯I⁻ hydrogen bonds, forming layers. Methyl‐H–borane‐H dihydride [–C—H(δ⁺)⋯(δ⁻)H—B–] inter­actions between mol­ecules crosslink adjacent layers, giving `sandwich' stacking along the a axis.     

Metabolic pathways of dithiocar­bamates from laboratory powder diffraction data

In order to correlate the reactivity and molecular structures of di­thio­carbamates, the crystal structures of 6-di­methyl­amino-5-nitro­pyrimidin-4-yl N,N-diethyl­di­thio­carbamate, C₁₁H₁₇N₅O₂S₂, (Ia), and 6-methyl­amino-5-nitro­pyrimidin-4-yl N,N-diethyl­di­thio­carbamate, C₁₀H₁₅N₅O₂S₂, (Ib), and of the product of thermolysis of (Ib), namely 4-diethyl­amino-6-methyl­amino-5-nitro­pyrimidinium chloride monohydrate, C₉H₁₆N₅O₂⁺·Cl⁻·H₂O, (II), have been determined from X-ray laboratory powder diffraction data. Conformational preferences in (Ia) and (Ib) were studied on the density functional theory (DFT) level. Deviation of the reaction centre of the mol­ecule from planarity and breakage of the secondary S⃛O contact cause switching between two alternative pathways of thermolysis.     

1,4‐Dimethyl‐1,4‐diazo­nia­bicyclo­[2.2.2]octane diiodide acetonitrile solvate

In the crystal structure of the title compound, C₈H₁₈N₂²⁺·2I⁻·CH₃CN, the dication lies on a mirror plane containing the mol­ecular dication threefold axis. The structure displays C—H⋯I inter­actions between H atoms of the 1,4‐dimethyl‐1,4‐diazo­nia­bicyclo­[2.2.2]octane dication and the iodide anions. The H⋯I distances are in the range 2.96–3.18 (4) Å. The dications pack forming channels along the b axis, which contain the iodide anions and acetonitrile solvent mol­ecules.     

Hydro­gen bonding in proton‐transfer compounds of 5‐sulfosalicylic acid with bicyclic heteroaromatic Lewis bases

The crystal structures of quinolinium 3‐carboxy‐4‐hydroxy­benzene­sulfonate trihydrate, C₉H₈N⁺·C₇H₅O₆S⁻·3H₂O, (I), 8‐hydroxy­quinolinium 3‐carboxy‐4‐hydroxy­benzene­sulfonate monohydrate, C₉H₈NO⁺·C₇H₅O₆S⁻·H₂O, (II), 8‐amino­quinolinium 3‐carboxy‐4‐hydroxy­benzene­sulfonate dihydrate, C₉H₉N₂⁺·C₇H₅O₆S⁻·2H₂O, (III), and 2‐carboxy­quinolinium 3‐carboxy‐4‐hydroxy­benzene­sulfonate quinolinium‐2‐carboxylate, C₁₀H₈NO₂⁺·C₇H₅O₆S⁻·C₁₀H₇NO₂, (IV), four proton‐transfer compounds of 5‐sulfosalicylic acid with bicyclic heteroaromatic Lewis bases, reveal in each the presence of variously hydrogen‐bonded polymers. In only one of these compounds, viz. (II), is the protonated quinolinium group involved in a direct primary N⁺—H⋯O(sulfonate) hydrogen‐bonding interaction, while in the other hydrates, viz. (I) and (III), the water mol­ecules participate in the primary intermediate interaction. The quinaldic acid (quinoline‐2‐carboxylic acid) adduct, (IV), exhibits cation–cation and anion–adduct hydrogen bonding but no direct formal heteromolecular interaction other than a number of weak cation–anion and cation–adduct π–π stacking associations. In all other compounds, secondary interactions give rise to network polymer structures.     

Tris(1,9‐diethyl­adeninium) triiodide diiodide

X‐ray analysis of the title compound reveals three crystallographically distinct cations of 1,9‐diethyl­adeninium, two iodide anions and one triiodide anion in the asymmetric unit, giving six residues and the formula 3C₉H₁₄N₅⁺·I₃⁻·2I⁻. Standard purine nomenclature is used to identify the atoms of each adenine moiety. Hydrogen bonding is observed between atoms N6 and N7 of a pair of cations [N⋯N = 2.885 (4)/2.902 (3) and 2.854 (3)/2.854 (3) Å], with additional hydrogen bonding to I⁻ anions via the other N6 H atom [N⋯I = 3.708 (3), 3.738 (3) and 3.638 (3) Å]. The triiodide anion is not involved in hydrogen bonding. The bond lengths and angles of the 1,9‐diethyl­adeninium cations are compared with literature values and confirm the formation of the imine tautomer.     

Ammonium 1‐hydroxy‐2‐(2‐pyridinio)ethane‐1,1‐diyldiphosphonate dihydrate and potassium 1‐hydroxy‐2‐(2‐pyridinio)ethane‐1,1‐diyldiphosphonate dihydrate

The crystal structures of the title compounds, ammonium risedronate dihydrate, NH₄⁺·C₇H₁₀NO₇P₂⁻·2H₂O, (I), and potassium risedronate dihydrate, K⁺·C₇H₁₀NO₇P₂⁻·2H₂O, (II), have been determined from single‐crystal X‐ray data collected at 120 K. Compound (I) forms a three‐dimensional hydrogen‐bonded network which connects the ammonium and risedronate ions and the water mol­ecules. In compound (II), the K⁺ ions are seven‐coordinated in a capped distorted trigonal prism. The coordination polyhedra form chains by corner‐sharing, and these chains are connected by phosphon­ate groups into layers in the ac plane. The layers are stacked and connected by hydrogen bonds in the b direction. The risedronate conformation is determined by intra­molecular inter­actions fine‐tuned by crystal packing effects. All H‐atom donors in both structures are involved in hydrogen bonding, with D⋯A distances between 2.510 (2) and 3.009 (2) Å.     

Hydro­gen bonding in proton‐transfer compounds of 8‐quinolinol (oxine) with aromatic sulfonic acids

The crystal structures of the proton‐transfer compounds of 8‐quinolinol (oxine) with the aromatic sulfonic acids 2‐amino­benzene­sulfonic acid (orthanilic acid) and 8‐hydroxy‐7‐iodo­quinoline‐5‐sulfonic acid (ferron) have been determined. In both 8‐hydroxy­quinolinium 2‐amino­benzene­sulfonate, C₉H₈NO⁺·C₆H₆NO₃S⁻, (I), and 8‐hydroxyquino­linium 8‐hydroxy‐7‐iodo­quinoline‐5‐sulfonate ses­qui­hydrate, C₉H₈NO⁺·C₉H₆INO₄S⁻·1.5H₂O, (II), extensive hydrogen‐bonding interactions, together with significant cation–cation [in (I)] and cation–anion [in (II)] π–π stacking associations, give rise to layered polymer structures.     

4-(Phenyldiazenyl)naphthalen-1-amine and its hydrochloride

The crystal structures of 4-(phenyl­diazenyl)­naphthalen-1-amine, C₁₆H₁₃N₃, (I), and its hydro­chloride, (4-amino­naph­thal­en-1-yl)­phenyl­diazenium chloride, C₁₆H₁₄­N₃⁺·­Cl⁻, (II), have been determined from X-ray single-crystal and powder data, respectively. The effect of the crystal environment on the molecular electronic structure was analysed on the AM1 level. One of the two symmetry-independent mol­ecules in (I) is involved in intermolecular hydrogen bonding, so that its dipole moment is twice as large as that of the other mol­ecule. The cations in (II) form stacks along [100], with the Cl⁻ anions forming hydrogen bonds to all three H atoms attached to N atoms.     

2,2′‐(Iminodimethylene)bis(1H‐benzimidazolium)(1+) chloride

The title compound, C₁₆H₁₆N₅⁺·Cl⁻ (nbbH⁺·Cl⁻), displays N—H⋯N, N—H⋯Cl and π–π inter­actions in the crystal packing. The Cl⁻ anion is chelated by the nbbH⁺ cation via two N—H⋯Cl hydrogen bonds. Inter‐ion N—H⋯N and N—H⋯Cl hydrogen bonds link ions related by 2₁ screw axes into chains along the c axis. These chains are further linked by glide‐plane operations to generate a three‐dimensional network, which is additionally stabilized by inter­chain π–π inter­actions.     

(Z)‐2‐Methylbuten‐1‐yl(aryl)iodonium trifluoromethanesulfonates containing electron‐withdrawing groups on the aryl moiety

The crystal structures of [(Z)‐2‐methyl­but‐1‐en‐1‐yl]­[4‐(tri­fluoro­methyl)­phenyl]­iodo­nium tri­fluoro­methane­sulfonate, C₁₂H₁₃F₃I⁺·CF₃O₃S^?, (I), (3,5‐di­chloro­phenyl)­[(Z)‐2‐methyl­but‐1‐en‐1‐yl]­iodo­nium tri­fluoro­methane­sulfonate, C₁₁H₁₂­Cl₂I⁺·CF₃O₃S^?, (II), and bis{[3,5‐bis­(tri­fluoro­methyl)­phenyl][(Z)‐2‐methyl­but‐1‐en‐1‐yl]­iodo­nium} bis­(tri­fluoro­methane­sulfonate) di­chloro­methane solvate, 2C₁₃H₁₂F₆I⁺·­2CF₃­O₃S^?·CH₂Cl₂, (III), are described. Neither simple acyclic β,β‐di­alkyl‐substituted alkenyl­(aryl)­idonium salts nor a series containing electron‐deficient aryl rings have been described prior to this work. Compounds (I)–(III) were found to have distorted square‐planar geometries, with each I atom interacting with two tri­fluoro­methane­sulfonate counter‐ions.     

Solid‐state architecture of saccharin salts of some diamines

Hydrazinium saccharinate, N₂H₅⁺·C₇H₄NO₃S⁻, crystallizes in a 1:1 ratio, while ethyl­ene­diaminium bis­(saccharinate), C₂H₁₀N₂²⁺·2C₇H₄NO₃S⁻, and butane‐1,4‐diaminium bis­(sac­charin­ate), C₄H₁₄N₂²⁺·2C₇H₄NO₃S⁻, form in a 1:2 cation–anion stoichiometry. The structures contain many strong hydrogen bonds of the N⁺—H⋯N⁻, N⁺—H⋯O, N—H⋯O and N—H⋯N types, with auxiliary C—H⋯O inter­actions.     

Hydrogen bonding in 1:1 proton‐transfer compounds of 5‐sulfosalicylic acid with 4‐X‐substituted anilines (X = F,Cl or Br)

The crystal structures of three proton‐transfer compounds of 5‐sulfosalicylic acid (3‐carboxy‐4‐hydroxy­benzene­sulfonic acid) with 4‐X‐substituted anilines (X = F, Cl and Br), namely 4‐fluoro­anilinium 5‐sulfosalicylate (3‐carboxy‐4‐hydroxybenzenesulfonate) monohydrate, C₆H₇FN⁺·C₇H₅O₆S⁻·H₂O, (I), 4‐chloro­anilinium 5‐sulfosalicylate hemihydrate, C₆H₇ClN⁺·C₇H₅O₆S⁻·0.5H₂O, (II), and 4‐bromo­anilinium 5‐sulfosalicylate monohydrate, C₆H₇BrN⁺·C₇H₅O₆S⁻·H₂O, (III), have been determined. The asymmetric unit in (II) contains two formula units. All three compounds have three‐dimensional hydrogen‐bonded polymeric structures in which both the water molecule and the carboxylic acid group are involved in structure extension. With both (II) and (III), which are structurally similar, the common cyclic (8) dimeric carboxylic acid association is present, whereas in (I), an unusual cyclic (8) association involving all three hetero‐species is found.     

The 1:1 cocrystals of the proton‐transfer compound dilituric acid–phenyl­biguanide monohydrate

A proton‐transfer compound, 1‐phenyl­biguanidium 5‐nitro‐2,6‐dioxo‐1,2,3,6‐tetra­hydro­pyrimidin‐4‐olate monohydrate, C₈H₁₂N₅⁺·C₄H₂N₃O₅⁻·H₂O, has been synthesized by a reaction between dilituric acid (5‐nitro‐2,4,6‐trihydroxy­pyrimi­dine, Dilit) and phenyl­biguanide (N‐phenyl­imido­carbonimidic diamide, Big). This compound cocrystallized as a 1:1 adduct, and the asymmetric unit consists of two dilituric amino–oxo planar tautomeric anions (Dilit⁻), two monoprotonated phenyl­biguanidium cations (BigH⁺) and two water mol­ecules of crystallization (Z′ = 2). Protonation occurs at the N atom attached to the phenyl ring of Big as a result of the proton‐transfer process from the acidic hydr­oxy group of Dilit. In the crystal structure, the hydrated 1:1 adduct is stabilized by 25 two‐ and three‐center hydrogen bonds.