Hydrogen‐bonded frameworks of bis(2‐carboxypyridinium) hexafluorosilicate and bis(2‐carboxyquinolinium) hexafluorosilicate dihydrate

In bis(2‐carboxypyridinium) hexafluorosilicate, 2C₆H₆NO₂⁺·SiF₆²⁻, (I), and bis(2‐carboxyquinolinium) hexafluorosilicate dihydrate, 2C₁₀H₈NO₂⁺·SiF₆²⁻·2H₂O, (II), the Si atoms of the anions reside on crystallographic centres of inversion. Primary inter‐ion interactions in (I) occur via strong N—H...F and O—H...F hydrogen bonds, generating corrugated layers incorporating [SiF₆]²⁻ anions as four‐connected net nodes and organic cations as simple links in between. In (II), a set of strong N—H...F, O—H...O and O—H...F hydrogen bonds, involving water molecules, gives a three‐dimensional heterocoordinated rutile‐like framework that integrates [SiF₆]²⁻ anions as six‐connected and water molecules as three‐connected nodes. The carboxyl groups of the cation are hydrogen bonded to the water molecule [O...O = 2.5533 (13) Å], while the N—H group supports direct bonding to the anion [N...F = 2.7061 (12) Å].     

Two salts of di‐p‐toluoyltartaric acid with aromatic amines

The structures of bis­[(R)‐(+)‐1‐phenyl­ethyl­ammonium] (2R,3R)‐(−)‐2,3‐di‐p‐toluoyloxybutane­dioate methanol disolvate monohydrate, 2C₈H₁₂N⁺·C₂₀H₁₆O₈²⁻·2CH₄O·H₂O, (I), and bis­(benzyl­ammonium) (2R,3R)‐(−)‐2,3‐di‐p‐toluoyl­oxy­butane­­dioate dihydrate, 2C₇H₁₀N⁺·C₂₀H₁₆O₈²⁻·2H₂O, (II), exhibit extensive hydrogen bonding, with (N—)H⋯O and (O—)H⋯O distances in the ranges 2.716 (2)–2.929 (3) and 2.687 (2)–2.767 (2) Å, respectively, in (I), and 2.673 (2)–2.888 (2) and 2.785 (2)–2.931 (2) Å, respectively, in (II). The amine groups are protonated and the carboxyl­ate groups of the tartrate anions are fully deprotonated. The conformation of the toluoyltartrate anion and its mol­ecular parameters are similar in both structures.     

Hydrogen phosphate and dihydrogen phosphate salts of 4‐amino­azobenzene

4‐Amino‐trans‐azobenzene {or 4‐[(E)‐phenyl­diazen­yl]aniline} can form isomeric salts depending on the site of protonation. Both orange bis{4‐[(E)‐phenyl­diazen­yl]anilinium} hydrogen phos­phate, 2C₁₂H₁₂N₃⁺·HPO₄²⁻, and purple 4‐[(E)‐phenyl­diazen­yl]­anilinium dihydrogen phosphate phosphoric acid solvate, C₁₂H₁₂N₃⁺·H₂PO₄⁻·H₃PO₄, (II), have layered structures formed through O—H⋯O and N—H⋯O hydrogen bonds. Additionally, azobenzene fragments in (I) are assembled through C—H⋯π inter­actions and in (II) through π–π inter­actions. Arguments for the colour difference are tentatively proposed.     

7‐Carboxyl­ato‐8‐hydroxy‐2‐methyl­quinolinium monohydrate and 7‐carboxy‐8‐hydroxy‐2‐methyl­quinolinium chloride monohydrate at 100 K

Both 7‐carboxyl­ato‐8‐hydroxy‐2‐methyl­quinolinium monohydrate, C₁₁H₉NO₃·H₂O, (I), and 7‐carboxy‐8‐hydroxy‐2‐methyl­quinolinium chloride monohydrate, C₁₁H₁₀NO₃⁺·Cl⁻·H₂O, (II), crystallize in the centrosymmetric P space group. Both compounds display an intramolecular O—H⋯O hydrogen bond involving the hydroxy group; this hydrogen bond is stronger in (I) due to its zwitterionic character [O⋯O = 2.4449 (11) Å in (I) and 2.5881 (12) Å in (II)]. In both crystal structures, the HN⁺ group participates in the stabilization of the structure via intermolecular hydrogen bonds with water mol­ecules [N⋯O = 2.7450 (12) Å in (I) and 2.8025 (14) Å in (II)]. In compound (II), a hydrogen‐bond network connects the Cl⁻ anion to the carboxylic acid group [Cl⋯O = 2.9641 (11) Å] and to two water mol­ecules [Cl⋯O = 3.1485 (10) and 3.2744 (10) Å].     

Tris­(methyl­ammonium) hydrogen­phosphate di­hydrogenphosphate

The title compound, 3CH₆N⁺·HPO₄²⁻·H₂PO₄⁻, aggregates with the moieties interconnected by O—H⋯O and N—H⋯O hydrogen bonds, with O⋯O and N⋯O distances in the ranges 2.5366 (16)–2.5785 (14) and 2.7437 (16)–2.9967 (18) Å, respectively. Three C—H⋯O hydrogen bonds are also present, with C⋯O distances in the range 3.2310 (18)–3.3345 (17) Å. All H atoms are ordered. Structures with ordered hydrogenphosphate and di­hydrogen­phosphate components are rare.     

Tripotassium tris­(oxalato‐κ2O,O′)­aluminate bis(hydrogen peroxide) hydrate,the first example of a cyclic hydrogen‐bonded H2O2 dimer

In addition to associating into cyclic hydrogen‐bonded dimers [O⋯O = 2.663 (1) and 2.914 (1) Å], each hydrogen peroxide mol­ecule in the title structure, K₃[Al(C₂O₄)₃]·1.75H₂O₂·0.25H₂O, hydrogen bonds to a neighbouring oxalate ligand [O⋯O = 2.700 (1) and 2.730 (1) Å] and coordinates to two K⁺ ions [K⋯O = 2.6620 (9)–2.8380 (7) Å].     

X‐ray studies of crystalline complexes involving amino acids and peptides. XLIII. Adipic acid complexes of l‐ and dl‐lysine

The asymmetric unit of the dl ‐lysine complex of adipic acid [bis­(dl ‐lysinium) adipate], 2C₆H₁₅N₂O₂⁺·C₆H₈O₄²⁻, contains a zwitterionic singly charged lysinium cation and half a doubly charged adipate anion (the complete anion has inversion symmetry). That of the l ‐lysine complex (lysinium hydrogen adipate), C₆H₁₅N₂O₂⁺·C₆H₉O₄⁻, consists of a lysinium cation and a singly charged hydrogen adipate anion. In both structures, the lysinium cations organize into layers inter­connected by adipate or hydrogen adipate anions. However, the arrangement of the mol­ecular ions in the layer is profoundly different in the dl ‐ and l ‐lysine complexes. The hydrogen adipate anions in the l ‐lysine complex form linear arrays in which adjacent ions are inter­connected by a symmetric O⋯H⋯O hydrogen bond.     

Comparison of the methyl ester of l‐tyrosine hydrochloride and its methanol monosolvate

Solvent‐free (2S)‐methyl 2‐ammonio‐3‐(4‐hydroxy­phenyl)­propionate chloride, C₁₀H₁₄NO₃⁺·Cl⁻, (I), and its methanol solvate, C₁₀H₁₄NO₃⁺·Cl⁻·CH₃OH, (II), are obtained from different solvents: crystallization from ethanol or propan‐2‐ol gives the same solvent‐free crystals of (I) in both cases, while crystals of (II) were obtained by crystallization from methanol. The structure of (I) is characterized by the presence of two‐dimensional layers linked together by N—H⋯Cl and O—H⋯Cl hydrogen bonds and also by C—H⋯O contacts. Incorporation of the methanol solvent mol­ecule in (II) introduces additional O—H⋯O hydrogen bonds linking the two‐dimensional layers, resulting in the formation of a three‐dimensional network.     

Sodium tris(glycinium) bis(hexafluorosilicate) glycine trisolvate

The title compound, Na⁺·3C₂H₆NO₂⁺·2SiF₆²⁻·3C₂H₅NO₂, arose from an unexpected reaction of glycine and HF with the glass container. It is an unusual hybrid organic–inorganic network built up from chains of vertex‐sharing NaF₄O₂ and SiF₆ octahedra. A pair of glycinium/glycine molecules bridges the chains into a sheet via a centrosymmetric O...H...O link. The other organic species interact with the network by an extensive N—H...F hydrogen‐bond network, including bifurcated and trifurcated bonds. Finally, an extremely short C—H...O interaction (H...O = 2.25 Å) is seen in the crystal structure. The Na atom has site symmetry .     

2,2′‐Bipyridinium(1+) bromide monohydrate

In the crystal structure of 2,2′‐bipyridinium(1+) bromide monohydrate, C₁₀H₉N₂⁺·Br⁻·H₂O, the cation has a cisoid conformation with an intramolecular N—H⋯N hydrogen bond. The cation also forms an N—H⋯O hydrogen bond to an adjacent water mol­ecule, which in turn forms O—H⋯Br⁻ hydrogen bonds to adjacent Br⁻ anions. In this way, a chain is formed extending along the b axis. Additional interactions (C—H⋯Br⁻ and π–π) serve to stabilize the structure further.     

Hexafluorosilicates of 2-substituted anilinium derivatives

The reaction of 45% fluorosilicic acid with methanol solutions of several 2-substituted anilines(L) gave hexafluorosilicates (LH)₂SiF₆. The products were studied by elemental analysis, IR spectroscopy, mass spectrometry, and thermogravimetry. The solubility and the hydrolytic stability of the salts were estimated. The structure of the complex [CH₃O(O)CC₆H₄NH₃]₂SiF₆ was determined by single-crystal X-ray diffraction. The ionic structure is composed of centrosymmetric SiF ₆ ^2? anions (the average Si-F bond length is 1.679(1) Å) and the [CH₃O(O)CC₆H₄NH₃]⁺ cations. The NH ₃ ⁺ group is the donor for the inner-cation H-bond with the carbonyl oxygen atom (NH···O), and for two ion-ion H-bonds (NH···F). The Si-F bond lengths correlate with the strengths of the H-bonds involving the corresponding fluorine atoms.     

Coexistence of two halide hydrate clusters in a crystal of 1,1′-(benzene-1,3-diyldimethanediyl)-bis(3,5,7-triaza-1-azoniatricyclo[3.3.1.13,7]decane) dibromide trihydrate. X-ray structure,Hirshfeld surface and thermal analysis

The title compound, C₂₀H₃₂N₈²⁺·2Br⁻·3H₂O, was obtained by the reaction of 1,3,5,7-triazatricyclo[3.3.1.1^3,7]decane with 1,3-bis(bromomethyl)benzene in acetonitrile. The asymmetric unit contains a unique 1,1′-(benzene-1,3-diyldimethanediyl)bis(3,5,7-triaza-1-azoniatricyclo[3.3.1.1^3,7]decane)dication, two bromide anions and three water molecules. The 3,5,7-triaza-1-azoniatricyclo[3.3.1.1^3,7]decane (C₆N₄H₁₂)⁺ moieties lie on the same side of the molecule, and the pseudo torsion angle (H₁₂N₄C₆)CH₂⋯CH₂(C₆N₄H₁₂) is −5.25 (18)°. The molecular dication C₂₀H₃₂N₈⁺ is charge-balanced by a pair of crystallographically independent halide hydrate clusters, and the cation and clusters are interlinked by CH⋯O and CH⋯Br hydrogen bonds. The Hirshfeld surface analysis and fingerprint plots reveal that the packing in compound 2 is directed mainly by H⋯H (56.7%) and H⋯Br/Br⋯H (21.3%) contacts. The thermal analysis showed between 30 and 180 °C the gradual loss of three water molecules, which represents the loss of one and two crystalline water molecules from the two types of clusters, respectively. A second noticeable weight loss between 180 and 230 °C is observed, depictive of the thermal decomposition of the dication of the title compound.     

Revealing the structural chemistry of the group 12 halide coordination compounds with 2,2′-bipyridine and 1,10-phenanthroline

The coordination compounds of group 12 halides with 2,2′-bipyridine (bpy) and 1,10-phenanthroline (phen), 2[CdF₂(bpy)₂]·7H₂O (1), [ZnI(bpy)₂]⁺·I₃^? (2), [CdI₂(bpy)₂] (3), [Cd(SiF₆)H₂O(phen)₂]·[Cd(H₂O)₂(phen)₂]²⁺·F^–·0.5(SiF₆)^2–·9H₂O (4), [Hg(phen)₃]²⁺·(SiF₆)^2–·5H₂O (5), [ZnBr₂(phen)₂] (6), 6[Zn(phen)₃]²⁺·12Br^–·26H₂O (7) and [ZnI(phen)₂]⁺·I^– (8), have been synthesized and characterized by X-ray crystallography, IR spectroscopy, elemental and thermal analysis. Structural investigations revealed that metal?:?ligand stoichiometry in the inner coordination sphere is 1?:?2 or 1?:?3. A diversity of intra- and intermolecular interactions exists in structures of 1–8, including the rare halogen?halogen and halogen?π interactions. The thermal and spectroscopic properties were correlated with the molecular structures of 1–8. Structural review of all currently known coordination compounds of group 12 halides with bpy and phen is presented.     

2‐Amino­benzimidazolium O‐ethyl malonate: eight independent N—H⋯O hydrogen bonds generate sheets

The title compound, C₇H₈N₃⁺·C₅H₇O₄⁻, crystallizes with Z′ = 2 in space group P2₁/c; eight independent N—H⋯O hydrogen bonds [H⋯O = 1.75–1.88 Å, N⋯O = 2.699 (2)–2.829 (2) Å and N—H⋯O = 147–179°] link the four inde­pendent ions into sheets.     

Symmetric hydrogen bonding in dimethyl­ammonium hydrogen diphenyl­diphospho­nate

In the title compound, C₂H₈N⁺·C₁₂H₁₁O₅P₂⁻, pairs of hydrogen diphenyl­diphospho­nate anions form dimers across a twofold axis, with two symmetric O⋯H⋯O hydrogen bonds [O⋯O = 2.406 (3) and 2.418 (3) Å]. The 12‐membered ring thus formed has crystallographic 2 and quasi‐222 symmetry. Cations on either side of the ring form N—H⋯O hydrogen bonds to the four extraannular O atoms, with N⋯O distances of 2.765 (2) and 2.748 (3) Å.     

Brucinium 3,5‐dinitro­benzoate methanol solvate,methanol disolvate and trihydrate

Crystals of brucinium 3,5‐dinitro­benzoate methanol solvate, C₂₃H₂₇N₂O₄⁺·C₇H₃N₂O₆⁻·CH₃OH, (I), brucinium 3,5‐dinitro­benzoate methanol disolvate, C₂₃H₂₇N₂O₄⁺·C₇H₃N₂O₆⁻·2CH₃OH, (II), and brucinium 3,5‐dinitro­benzoate trihydrate, C₂₃H₂₇N₂O₄⁺·C₇H₃N₂O₆⁻·3H₂O, (III), were obtained from methanol [for (I) and (II)] or ethanol solutions [for (III)]. The brucinium cations and 3,5‐dinitro­benzoate anions are linked by ionic N—H⁺⋯O⁻ hydrogen bonds. In the crystals of (I), (II) and (III), the brucinium cations exhibit different modes of packing, viz. corrugated ribbons, pillars and corrugated monolayer sheets, respectively. While in (III), the amide O atom of the brucinium cation participates in O—H⋯O hydrogen bonds, in which water mol­ecules are the donors, in (I) and (II), the amide O atom of the brucinium cation is involved in weak C—H⋯O hydrogen bonds and other brucinium cations are the donors.     

Berberine formate–succinic acid (1/1)

The title compound [systematic name: 9,10‐di­methoxy‐2,3‐methyl­ene­dioxy‐5,6‐di­hydro­dibenzo­[a,g]­quinolizinium form­ate–succinic acid (1/1)], C₂₀H₁₈NO₄⁺·CHO₂⁻·C₄H₆O₄, con­tains centrosymmetric pairs of almost planar berberine cations, and hydrogen‐bonded (C₄H₆O₄⋯HCOO⁻)₂ rings of succinic acid with formate anions, bonded by O—H⋯O hydrogen bonds with O⋯O distances of 2.4886 (15) and 2.5652 (16) Å. Pairs of cations and mol­ecules of succinic acid are connected by non‐conventional weak C—H⋯O hydrogen bonds, with C⋯O distances of 3.082 (2) and 3.178 (2) Å.     

Isomorphous crystals of strychninium 4‐chloro­benzoate and strychninium 4‐nitro­benzoate

In strychninium 4‐chloro­benzoate, C₂₁H₂₃N₂O₂⁺·C₇H₄ClO₂⁻, (I), and strychninium 4‐nitro­benzoate, C₂₁H₂₃N₂O₂⁺·C₇H₄NO₄⁻, (II), the strychninium cations form pillars stabilized by C—H⋯O and C—H⋯π hydrogen bonds. Channels between the pillars are occupied by anions linked to one another by C—H⋯π hydrogen bonds. The cations and anions are linked by ionic N—H⁺⋯O⁻ and C—H⋯X hydrogen bonds, where X = O, π and Cl in (I), and O and π in (II).     

(R)‐1‐Phenyl­ethyl­ammonium 6‐amino‐5‐nitro­pyrimidine‐2,4(1H,3H)‐dionate (R)‐1‐phenyl­ethyl­amine hemisolvate: hydrogen‐bonded sheets of ions with pendent solvent mol­ecules

In the title compound, 2C₈H₁₂N⁺·2C₄H₃N₄O₄⁻·C₈H₁₁N, the anions are linked by paired N—H⋯N hydrogen bonds [H⋯N = 2.07 and 2.11 Å, N⋯N = 2.942 (3) and 2.978 (3) Å and N—H⋯N = 173 and 170°] and by paired N—H⋯O hydrogen bonds [H⋯O = 1.98 and 2.05 Å, N⋯O = 2.855 (3) and 2.917 (3) Å, and N—H⋯O = 173 and 167°] into chains of rings. These chains are linked into sheets by further N—H⋯O hydrogen bonds in which all of the donors are provided by the cations [H⋯O = 1.83–2.17 Å, N⋯O = 2.747 (3)–2.965 (3) Å and N—H⋯O = 141–168°]. The neutral amine molecule is pendent from the sheet and is linked to it by a single N—H⋯N hydrogen bond [H⋯N = 2.00 Å, N⋯N = 2.901 (3) Å and N—H⋯N = 175°].     

Bis(iminodiethylenedi­ammonium) di‐μ5‐hydrogen­phosphato‐penta­molybdate(VI) tetra­hydrate

The crystal structure of the title compound, (C₄H₁₅N₃)₂[Mo₅O₁₅(HPO₄)₂]·4H₂O, is made up of [Mo₅O₁₅(HPO₄)₂]⁴⁻ clusters, iminodiethylenediammonium cations and solvent water mol­ecules. The [Mo₅O₁₅(HPO₄)₂]⁴⁻ cluster, with approximate C₂ symmetry, can be considered as a ring formed by five distorted edge‐ and corner‐sharing MoO₆ octa­hedra, capped on both poles by a hydro­phosphate tetra­hedron. There exist N—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds between the organic ammonium groups and the clusters, with inter­atomic N⋯O distances ranging from 2.675 (3) to 2.999 (3) Å, and C⋯O distances ranging from 3.139 (5) to 3.460 (5) Å.