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.     

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].     

Hydro­gen‐bonded supramolecular motifs in 4,4′‐bipyridinium 8‐hydroxy‐7‐iodo­quinoline‐5‐sulfonate dihydrate

In the title compound, C₁₀H₉N₂⁺·C₉H₅INO₄S⁻·2H₂O, the 4,4′‐bi­pyridine mol­ecule is protonated at one of the pyridine N atoms. These moieties self‐assemble into a supramolecular chain along the a axis through N—H⋯N hydrogen bonds. The quinolinol OH group acts as a donor with respect to a sulfonate O atom [O—H⋯O(sulfonate)] and acts as an acceptor with respect to a C—H group of ferron [C—H⋯O(hydroxy)], forming a supramolecular chain along the b axis. These two types of supramolecular chains (one type made up of bi­pyridine motifs and the other made up of sulfoxine motifs) interact viaπ–π stacking, generating a three‐dimensional framework. These chains are further crosslinked by C—­H⋯O hydrogen bonds and O—H⋯O hydrogen bonds involving water mol­ecules.     

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).     

Different nucleobase orientations in two cyclic 2′,3′‐phosphates of purine ribonucleosides: Et3NH(2′,3′‐cAMP) and Et3NH(2′,3′‐cGMP)·H2O

The crystal structures of triethyl­ammonium adenosine cyclic 2′,3′‐phosphate {systematic name: triethyl­ammonium 4‐(6‐amino­purin‐9‐yl)‐6‐hydroxy­methyl‐2‐oxido‐2‐oxoperhydro­furano[3,4‐c][1,3,2]dioxaphosphole}, Et₃NH(2′,3′‐cAMP) or C₆H₁₆N⁺·C₁₀H₁₁N₅O₆P⁻, (I), and guanosine cyclic 2′,3′‐phosphate monohydrate {systematic name: triethyl­ammonium 6‐hydroxy­methyl‐2‐oxido‐2‐oxo‐4‐(6‐oxo‐1,6‐dihydro­purin‐9‐yl)perhydro­furano[3,4‐c][1,3,2]dioxaphosphole monohydrate}, [Et₃NH(2′,3′‐cGMP)]·H₂O or C₆H₁₆N⁺·C₁₀H₁₁N₅O₇P⁻·H₂O, (II), reveal different nucleobase orientations, viz. anti in (I) and syn in (II). These are stabilized by different inter‐ and intra­molecular hydrogen bonds. The structures also exhibit different ribose ring puckering [₄E in (I) and ³T₂ in (II)] and slightly different 1,3,2‐dioxaphospho­lane ring conformations, viz. envelope in (I) and puckered in (II). Infinite ribbons of 2′,3′‐cAMP⁻ and helical chains of 2′,3′‐cGMP⁻ ions, both formed by O—H⋯O, N—H⋯X and C—H⋯X (X = O or N) hydrogen‐bond contacts, characterize (I) and (II), respectively.     

3,4‐Di‐2‐pyridyl‐1,2,5‐oxadiazole and its perchlorate salt

In 3,4‐di‐2‐pyridyl‐1,2,5‐oxadiazole (dpo), C₁₂H₈N₄O, each mol­ecule resides on a twofold axis and inter­acts with eight neighbours via four C—H⋯N and four C—H⋯O inter­actions to generate a three‐dimensional hydrogen‐bonded architecture. In the perchlorate analogue, 2‐[3‐(2‐pyrid­yl)‐1,2,5‐oxadiazol‐4‐yl]pyridinium perchlorate, C₁₂H₉N₄O⁺·ClO₄⁻ or [Hdpo]ClO₄, the [Hdpo]⁺ cation is bisected by a crystallographic mirror plane, and the additional H atom in the cation is shared by the two pyridyl N atoms to form a symmetrical intra­molecular N⋯H⋯N hydrogen bond. The cations and perchlorate anions are linked through C—H⋯O hydrogen bonds and π–π stacking inter­actions to form one‐dimensional tubes along the b‐axis direction.     

Two phosphate–imidazole complexes with and without a hydrogen‐bonded guest mol­ecule

The mol­ecular structures of the complexes imidazolium 6,6′‐di‐tert‐butyl‐4,4′‐dimethyl‐2,2′‐thio­diphenyl phosphate, C₃H₅N₂⁺·C₂₂H₂₈O₄PS⁻, (I), and imidazolium 6,6′‐di‐tert‐butyl‐4,4′‐dimethyl‐2,2′‐thio­diphenyl phosphate diisopropyl hydrazo­dicarboxyl­ate hemisolvate, C₃H₅N₂⁺·C₂₂H₂₈O₄PS⁻·0.5C₈H₁₆N₂O₄, (II), have been determined. While (I) forms the expected hydrogen‐bonded chain utilizing the two imidazole N‐bound H atoms, in (II), the substituted hydrazine solvent mol­ecule inserts itself between the chains. Compound (I) exhibits a strong N—H⋯O hydrogen bond, with an N⋯O distance of 2.603 (2) Å. The hydrazine solvent molecule in (II) lies about a twofold axis and the N‐bound H atoms are involved in bifurcated hydrogen bonds with phosphate O atoms. A C‐bound H atom of the imidazolium cation is involved in a C—H⋯O inter­action with a carbonyl O atom of the hydrazine solvent mol­ecule.     

Supramolecular hydrogen‐bonded networks in cytosinium succinate and cytosinium 4‐nitrobenzoate cytosine monohydrate

In cytosinium succinate (systematic name: 4‐amino‐2‐oxo‐2,3‐dihydropyrimidin‐1‐ium 3‐carboxypropanoate), C₄H₆N₃O⁺·C₄H₅O₄⁻, (I), the cytosinium cation forms one‐dimensional self‐assembling patterns by intermolecular N—H...O hydrogen bonding, while in cytosinium 4‐nitrobenzoate cytosine monohydrate [systematic name: 4‐amino‐2‐oxo‐2,3‐dihydropyrimidin‐1‐ium 4‐nitrobenzoate 4‐aminopyrimidin‐2(1H)‐one solvate monohydrate], C₄H₆N₃O⁺·C₇H₄NO₄⁻·C₄H₅N₃O·H₂O, (II), the cytosinium–cytosine base pair, held together by triple hydrogen bonds, leads to one‐dimensional polymeric ribbons via double N—H...O hydrogen bonds. This study illustrates clearly the different alignment of cytosine molecules in the crystal packing and their ability to form supramolecular hydrogen‐bonded networks with the anions.     

trans‐Di­aqua­bis(5‐carboxy‐1H‐imidazole‐4‐carboxyl­ato‐κ2N3,O4)­cobalt(II) 4,4′‐bi­pyridine solvate

In the title compound, [Co(C₅H₃N₂O₄)₂(H₂O)₂]·C₁₀H₈N₂, the Co atom is trans‐coordinated by two pairs of N and O atoms from two monoanionic 4,5‐di­carboxy­imidazole ligands, and by two O atoms from two coordinated water mol­ecules, in a distorted octahedral geometry. The 4,4′‐bi­pyridine solvent molecule is not involved in coordination but is linked by an N—H⋯N hydrogen bond to the neutral [Co(C₅H₃N₂O₄)₂(H₂O)₂] mol­ecule. Both mol­ecules are located on inversion centers. The crystal packing is stabilized by N—H⋯N and O—H⋯O hydrogen bonds, which produce a three‐dimensional hydrogen‐bonded network. Offset π–π stacking interactions between the pyridine rings of adjacent 4,4′‐bi­pyridine molecules were observed, with a face‐to‐face distance of 3.345 (1) Å.     

2‐Aminopyridinium benzoate

Cyclic eight‐membered hydrogen‐bonded rings exist in the title compound, C₅H₇N₂⁺·C₇H₅O₂⁻, involving the 2‐amino­pyridinium and benzoate ions. Each benzoate ion has two intramolecular hydrogen bonds. 2‐Amino­pyridinium benzoate ion pairs are linked by N—H⋯O hydrogen bonds, with an N⋯O distance of 2.8619 (14) Å.     

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.     

Three‐dimensional hydrogen‐bonding supramolecular architecture of 2‐(3‐pyridinio)‐5‐(3‐pyridyl)‐1,3,4‐oxa­diazole perchlorate

In the crystal structure of the title compound, C₁₂H₉N₄O⁺·ClO₄⁻, the protonated cation adopts a cis‐I conformation and approximately planar geometry. Each perchlorate anion acts as the acceptor of three C—H⋯O weak interactions, which, together with N—H⋯N and C—H⋯N hydrogen bonds between the protonated cations, extend this structure into a three‐dimensional hydrogen‐bonded network.     

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.     

Thia­mine tetra­phenyl­borate monohydrate: a two‐dimensional hydrogen‐bonded network with (4,4)‐topology

The title compound, 3‐[(4‐amino‐2‐methyl­pyrimidin‐5‐yl)­meth­yl]‐5‐(2‐hydroxy­eth­yl)‐4‐methyl­thia­zolium tetra­phenyl­borate monohydrate, C₁₂H₁₇N₄OS⁺·C₂₄H₂₀B⁻·H₂O, is a salt in which the thiamine cations are linked by hydrogen bonds into a two‐dimensional network having (4,4)‐topology. The stacked sheets form channels, which are occupied by the anions; the cations and anions are linked by C—H⋯π(arene) hydrogen bonds.     

Tris(1H‐benzimidazol‐2‐yl­meth­yl)­amine–solvent adducts

The tris­(1H‐benzimidazol‐2‐yl­meth­yl)­amine (ntb) mol­ecule crystallizes in different solvent systems, resulting in two kinds of adduct, namely the monohydrate, C₂₄H₂₁N₇·H₂O or ntb·H₂O, (I), and the acetonitrile–methanol–water (1/0.5/1.5) solvate, C₂₄H₂₁N₇·C₂H₃N·0.5CH₄O·1.5H₂O or ntb·1.5H₂O·0.5MeOH·MeCN, (II). In both cases, ntb adopts a tripodal mode to form hydrogen bonds with a solvent water mol­ecule via two N—H⋯O and one O—H⋯N hydrogen bond. In (I), the ntb·H₂O adduct is further assembled into a two‐dimensional network by N—H⋯N and O—H⋯N hydrogen bonds, while in (II), a double‐stranded one‐dimensional chain structure is assembled via N—H⋯O and O—H⋯O hydrogen bonds, with the acetonitrile mol­ecules located inside the cavities of the chain structure.     

The anilinium chloride adduct of 4‐bromo‐N‐phenylbenzene­sulfonamide

The title compound anilinium chloride–4‐bromo‐N‐phenyl­benzene­sulfonamide (1/1), C₆H₈N⁺·Cl⁻·C₁₂H₁₀BrNO₂S, displays a hydrogen‐bonded ladder motif with four independent N—H⋯Cl bonds in which both the NH group of the sulfonamide molecule and the NH₃ group of the anilinium ion [N⋯Cl = 3.135 (3)–3.196 (2) Å and N—H⋯Cl = 151–167°] are involved. This hydrogen‐bonded chain contains two independent R₄²(8) rings and each chloride ion acts as an acceptor of four hydrogen bonds.     

Proton‐transfer compounds of 8‐hydroxy‐7‐iodoquinoline‐5‐sulfonic acid (ferron) with 4‐chloroaniline and 4‐bromoaniline

The crystal structures of the proton‐transfer compounds of ferron (8‐hydroxy‐7‐iodoquinoline‐5‐sulfonic acid) with 4‐chloroaniline and 4‐bromoaniline, namely 4‐chloroanilinium 8‐hydroxy‐7‐iodoquinoline‐5‐sulfonate monohydrate, C₆H₇ClN⁺·C₉H₅INO₄S⁻·H₂O, and 4‐bromoanilinium 8‐hydroxy‐7‐iodoquinoline‐5‐sulfonate monohydrate, C₆H₇BrN⁺·C₉H₅INO₄S⁻·H₂O, have been determined. The compounds are isomorphous and comprise sheets of hydrogen‐bonded cations, anions and water molecules which are extended into a three‐dimensional framework structure through centrosymmetric R₂²(10) O—H...N hydrogen‐bonded ferron dimer interactions.     

1:1 Adducts of 2,2′‐[isopropylidenebis(p‐phenyleneoxy)]diacetic acid with dimethylammonium and 4,4′‐bipyridine

The title compounds, dimethylammonium 2‐{4‐[1‐(4‐carboxymethoxyphenyl)‐1‐methylethyl]phenoxy}acetate, C₂H₈N⁺·C₁₉H₁₉O₆⁻, (I), and 2,2′‐[isopropylidenebis(p‐phenyleneoxy)]diacetic acid–4,4′‐bipyridine (1/1), C₁₉H₂₀O₆·C₁₀H₈N₂, (II), are 1:1 adducts of 2,2′‐[isopropylidenebis(p‐phenyleneoxy)]diacetic acid (H₂L) with dimethylammonium or 4,4′‐bipyridine. The component ions in (I) are linked by N—H...O, O—H...O and C—H...O hydrogen bonds into continuous two‐dimensional layers parallel to the (001) plane. Adjacent layers are stacked via C—H...O hydrogen bonds into a three‐dimensional network with an –ABAB– alternation of the two‐dimensional layers. In (II), two H₂L molecules, one bipy molecule and two half bipy molecules are linked by O—H...N hydrogen bonds into one‐dimensional chains and rectanglar‐shaped rings. They are assembled viaπ–π stacking interactions and C—H...O hydrogen bonds into an intriguing zero‐dimensional plus one‐dimensional poly(pseudo)rotaxane motif.     

Bis(4,4′‐bi­pyridine‐κN)­bis­(hydrogen phthalato)‐κ2O,O′;κO‐zinc(II)

The title compound, [Zn(C₈H₅O₄)₂(C₁₀H₈N₂)₂], was obtained by the hydro­thermal reaction of ZnSO₄·7H₂O with phthalic acid (H₂pht) and 4,4′‐bi­pyridine (4,4′‐bipy). Crystallographic analysis shows that it has a one‐dimensional double‐chain structure via hydrogen‐bonding interactions. Each Zn^II atom, adopting a distorted tetrahedral geometry, is coordinated by two N atoms from two 4,4′‐bipy ligands, with Zn—N distances of 2.054 (4) and 2.104 (4) Å, and by two O atoms from symmetry‐related Hpht⁻ ligands, with Zn—O distances of 1.921 (4) and 2.019 (4) Å.     

Co‐crystallization of hemimellitic acid with 4,4′‐bipyridine forming a pillar‐layered hydrogen‐bonded network

Co‐crystallization of hemimellitic acid (benzene‐1,2,3‐tricarboxylic acid) dihydrate (H₃HMA·2H₂O) with 4,4′‐bipyridine (4,4′‐bpy) affords the 1:1 co‐crystal benzene‐1,2,3‐tricarboxylic acid–4,4′‐bipyridine (1/1), H₃HMA·4,4′‐bpy or C₉H₆O₆·C₁₀H₈N₂. Strong O—H⋯O hydrogen bonds connect the acid mol­ecules to form a one‐dimensional zigzag chain, around which the 4,4′‐bpy components are fixed as arms via O—H⋯N inter­actions, resulting in a ladder motif. Through weak C—H⋯O non‐covalent forces, the resulting acid layers are extended into a three‐dimensional pillar‐layered architecture supported by rod‐like 4,4′‐bpy components. The influence on hydrogen‐bonding models is also discussed, with the discovery of an unexpected inter­action motif that does not follow the routine hydrogen‐bonded hierarchical rule in the construction of an acid–base co‐crystal.