Two rhod­amine derivatives: 9‐[2‐(ethoxycarbonyl)phenyl]‐3,6‐bis(ethyl­amino)‐2,7‐di­methyl­xanthyl­ium chloride monohydrate and 3,6‐di­amino‐9‐[2‐(methoxy­carbonyl)­phenyl]xanthyl­ium chloride trihydrate

The title compounds, C₂₈H₃₁N₂O₃⁺·Cl^?·H₂O (common name rhod­amine‐6g), (I), and C₂₁H₁₇N₂O₃⁺·Cl^?·3H₂O (common name rhod­amine‐123), (II), both have planar xanthene skeletons with a formal +1 charge on the amino N atoms delocalized through the π‐electron system so that the N—Csp² bond distances indicate significant double‐bond character. The substituted planar phenyl groups make angles of 63.29 (8) and 87.96 (11)° with the xanthene planes in (I) and (II), respectively. In both mol­ecules, the carbonyl bond vectors point toward the xanthene rings. The ethyl­amine groups in (I) are oriented similarly with their CH₂–CH₃ bond vectors pointing nearly perpendicular to the xanthene plane. The chloride ions and water mol­ecules are disordered in both structures. In (I), the chloride ion and water mol­ecule are disordered between two sites. One water and chloride alternately occupy the same site with occupancy factors of 0.5. The other 0.5‐chloride and 0.5‐water occupy two distinct positions separated by 0.747 (8) Å. In (II), the chloride ion is disordered between three sites and one of the waters is disordered about two other sites. Both crystal structures are stabilized by hydrogen bonds involving the chloride ions, amino groups and water mol­ecules, as well as by π–π stacking between xanthene planes.     

Hydro­gen‐bonded adducts of ferrocene‐1,1′‐diyl­bis­(di­phenyl­methanol): monomeric and polymeric adducts with 1,2‐bis(4‐pyridyl)­ethene and 1,6‐di­amino­hexane

In the adduct ferrocene‐1,1′‐diyl­bis­(di­phenyl­methanol)–1,2‐bis(4‐pyridyl)­ethene (1/1), [Fe(C₁₈H₁₅O)₂]·C₁₂H₁₀N₂, there is an intramolecular O—H?O hydrogen bond in the ferro­cene­diol component and a single O—H?N hydrogen bond linking the diol to the di­amine, which is disordered over two sets of sites, so forming a finite monomeric adduct. In the adduct ferrocene‐1,1′‐diyl­bis­(di­phenyl­methanol)–1,6‐di­amino­hexane (2/1), 2[Fe(C₁₈H₁₅O)₂]·C₆H₁₆N₂, the amine lies across a centre of inversion in space group P. There is an intramolecular O—H?O hydrogen bond in the ferrocenediol, and the molecular components are linked by O—H?N and N—H?O hydrogen bonds, one of each type, into a C(13)[R(12)] chain of rings.     

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].     

The salt‐type 1:2 adduct of meso‐5,5,7,12,12,14‐hexa‐C‐methyl‐1,4,8,11‐tetraazacyclotetradecane (tet‐a) and 5‐nitroisophthalic acid forms a hydrogen‐bonded sheet ­structure containing two configur­ational isomers of [(tet‐a)H2]2+

The title compound, meso‐5,7,7,12,14,14‐hexa­methyl‐4,11‐di­aza‐1,8‐diazo­nia­cyclo­tetra­decane bis(3‐carboxy‐5‐nitro­benz­oate), C₁₆H₃₈N₄²⁺·2C₈H₄NO₆^?, is a salt in which the cation is present as two configurational isomers, disordered across a common centre of inversion in P, with occupancies of 0.847 (3) and 0.153 (3). The anions are linked into chains by a single O—H?O hydrogen bond [H?O 1.71 Å, O?O 2.5063 (15) Å and O—H?O 156°] and the cations link these anion chains into sheets by means of a range of N—H?O hydrogen bonds [H?O 1.81–2.53 Å, N?O 2.718 (5)–3.3554 (19) Å and N—H?O 146–171°].     

Hydro­gen‐bonded adducts of ferrocene‐1,1′‐diyl­bis­(di­phenyl­methanol): monomeric and dimeric 1:1 adducts with 1,2‐bis(4‐pyridyl)­ethane and 1,2‐­diamino­ethane

In ferrocene‐1,1′‐diyl­bis­(di­phenyl­methanol)–4,4′‐ethyl­enedi­pyridine (1/1), [Fe(C₁₈H₁₅O)₂]·C₁₂H₁₂N₂, there is an intra­molecular O—H?O hydrogen bond in the ferrocenediol component and a single O—H?N hydrogen bond linking the two components into a finite monomeric adduct. Ferrocene‐1,1′‐diyl­bis­(di­phenyl­methanol)–ethyl­enedi­amine (1/1), [Fe(C₁₈H₁₅O)₂]·C₂H₈N₂, crystallizes with Z′ = 2 in space group P, and there are two independent four‐component aggregates in the structure, both of which are centrosymmetric. In the first type of aggregate, the molecular components are linked by O—H?N and N—H?O hydrogen bonds, in which both di­amine N atoms participate; in the second type of aggregate, the di­amine component is disordered over two sets of sites, but only one N atom is involved in the hydrogen bonding.     

Two hydro­chlorides of 7‐methyl‐3,7,11,17‐tetra­aza­bi­cyclo­[11.3.1]­heptadeca‐1(17),13,15‐triene

The X‐ray structure determinations of the two title com­pounds, namely 7‐methyl‐7,17‐di­aza‐3,11‐diazo­niabi­cyclo[11.3.1]­hep­ta­deca‐1(17),13,15‐triene dichloride monohydrate, C₁₄H₂₆N₄²⁺·2Cl^?·H₂O, (I), and 7‐methyl‐17‐aza‐3,7,11‐triazo­niabi­cyclo­[11.3.1]­heptadeca‐1(17),13,15‐triene 2.826‐chloride 0.174‐nitrate, C₁₄H₂₇N₄³⁺·2.826Cl^?·0.174NO₃^?, (II), are re­ported. Protonation occurs at the secondary amine N atoms in (I) and at all three amine N atoms in (II) to which the Cl^? ions are linked via N—H?Cl hydrogen bonds. The macrocyclic hole is quite different in both structures, as is observed by comparing particularly the N3?N4 distances [2.976 (4) and 4.175 (4) Å for (I) and (II), respectively]. In (II), a Cl^? ion alternates with an NO₃^? ion in a disordered structure.     

Sodium 2‐oxo‐3‐semicarbazono‐2,3‐dihydro‐1H‐indole‐5‐sulfonate dihydrate

The title compound, Na⁺·C₉H₇N₄O₅S⁻·2H₂O, presents a Z configuration around the imine C=N bond and an E configuration around the C(O)NH₂ group, stabilized by two intra­molecular hydrogen bonds. The packing is governed by ionic inter­actions between the Na⁺ cation and the surrounding O atoms. The ionic unit, Na⁺ and 2‐oxo‐3‐semicarbazono‐2,3‐dihydro‐1H‐indole‐5‐sulfonate, forms layers extending in the bc plane. The layers are connected by hydrogen bonds involving the water mol­ecules.     

7‐Vinyl‐8‐aza‐7‐de­aza‐2′‐deoxy­adenosine monohydrate

In the title compound, 4‐amino‐1‐(2‐deoxy‐β‐d ‐eythro‐pento­furan­osyl)‐3‐vinyl‐1H‐pyrazolo­[3,4‐d]­pyrimidine monohydrate, C₁₂H₁₅N₅O₃·H₂O, the conformation of the gly­cosyl bond is anti. The furan­ose moiety is in an S conformation with an unsymmetrical twist, and the conformation at the exocyclic C—C(OH) bond is +sc (gauche, gauche). The vinyl side chain is bent out of the heterocyclic ring plane by 147.5 (5)°. The three‐dimensional packing is stabilized by O—H·O, O—H·N and N—H·O hydrogen bonds.     

Λ‐{1,4,7,10‐Tetrakis­[(S)‐2‐hydroxy­propyl‐κO]‐1,4,7,10‐tetra­aza­cyclo­do­decane‐κ4N}cadmium(II) bis(2,4,6‐tri­nitro­phenolate) aceto­nitrile solvate

Crystallization of [Cd(S‐thpc12)](ClO₄)₂·H₂O {S‐thpc12 is 1,4,7,10‐tetrakis­[(S)‐2‐hydroxy­propyl]‐1,4,7,10‐tetra­aza­cyclo­do­decane} in the presence of two equivalents of sodium picrate monohydrate (sodium 2,4,6‐tri­nitro­phenolate monohydrate) diastereoselectively produces a neutral receptor complex, viz. the title compound, Λ‐[Cd(C₂₀H₄₄N₄O₄)](C₆H₂N₃O₇)₂·CH₃CN. In this complex, two picrate anions hydrogen bond, via their phenolate moieties, to the pendant hydroxyl groups of the receptor which, together with the four N atoms, themselves bond to Cd^II in an approximately cubic arrangement. One picrate anion hydrogen bonds to all four hydroxyl groups, one of which also acts as the sole hydrogen‐bond donor to the second picrate anion.     

2‐Pyridone–tartronic acid (1/1), 3‐hydroxy­pyridinium hydrogen tartronate and 4‐hydroxy­pyridinium hydrogen tartronate

Tartronic acid forms a hydrogen‐bonded complex, C₅H₅NO·C₃H₄O₅, (I), with 2‐pyridone, while it forms acid salts, namely 3‐hydroxy­pyridinium hydrogen tartronate, (II), and 4‐hy­droxy­pyridinium hydrogen tartronate, (III), both C₅H₆NO⁺·C₃H₃O₅⁻, with 3‐hydroxy­pyridine and 4‐hydroxy­pyridine, respectively. In (I), the pyridone mol­ecules and the acid mol­ecules form R(8) and R(10) hydrogen‐bonded rings, respectively, around the inversion centres. In (II) and (III), the cations and anions are linked by N—H⋯O and O—H⋯O hydrogen bonds to form a hydrogen‐bonded chain. In each of (I), (II) and (III), an intermolecular hydrogen bond is formed between a carboxyl group and the hydroxyl group attached to the central C atom, and in (I), the hydroxyl group participates in an intramolecular hydrogen bond with a carbonyl group. No intermolecular hydrogen bond is formed between the carboxyl groups in (I), or between the carboxyl and carboxyl­ate groups in (II) and (III).     

Tris[2‐(1,3‐thiazol‐2‐yl‐κN)‐1H‐benzimidazole‐κN3]zinc(II) dinitrate ethanol hemisolvate monohydrate at 100 K

The Zn^II center in the dicationic complex of the title compound, [Zn(C₁₀H₇N₃S)₃](NO₃)₂·0.5C₂H₅OH·H₂O, is in a distorted octahedral environment with imperfect noncrystallographic C₃ symmetry. Each 2‐(1,3‐thiazol‐2‐yl)‐1H‐benzimidazole ligand coordinates in a bidentate manner, with the Zn—N(imidazole) bond lengths approximately 0.14 Å shorter than the Zn—N(thiazole) bond lengths. Charge‐assisted hydrogen bonds connect cations, anions and water molecules. A lattice void is occupied by an ethanol solvent molecule disordered about a crystallographic inversion center and π‐stacking is observed between one type of symmetry‐related benzene rings.     

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.     

8‐Aza‐7‐deaza‐7‐propynyladenosine methanol solvate

In the title compound, 4‐amino‐3‐propynyl‐1‐(β‐d ‐ribofur­anosyl)‐1H‐pyrazolo[3,4‐d]pyrimidine methanol solvate, C₁₃H₁₅N₅O₄·CH₃OH, the torsion angle of the N‐glycosylic bond is between anti and high‐anti [χ = −101.8 (5)°]. The ribofuranose moiety adopts the C3′‐endo (³T₂) sugar conformation (N‐type) and the conformation at the exocyclic C—C bond is +sc (gauche, gauche). The propynyl group is out of the plane of the nucleobase and is bent. The compound forms a three‐dimensional network which is stabilized by several hydrogen bonds (O—H·O and O—H·N). The nucleobases are stacked head‐to‐tail. The methanol solvent mol­ecule forms hydrogen bonds with both the nucleobase and the sugar moiety.     

N8‐(2′‐O‐Methyl­ribofuranos­yl)‐8‐aza‐7‐deaza­adenine monohydrate

In the title compound, 4‐amino‐2‐(2‐O‐methyl‐β‐d ‐ribofuranos­yl)‐2H‐pyrazolo[3,4‐d]pyrimidine monohydrate, C₁₁H₁₅N₅O₄·H₂O, the conformation of the N‐glycosylic bond is syn [χ = 20.1 (2)°]. The ribofuran­ose moiety shows a C3′‐endo (³T₂) sugar puckering (N‐type sugar), and the conformation at the exocyclic C4′—C5′ bond is −ap (trans). The nucleobases are stacked head‐to‐head. The three‐dimensional packing of the crystal structure is stabilized by hydrogen bonds between the 2′‐O‐methyl­ribonucleosides and the solvent mol­ecules.     

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.     

3,4‐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.     

1‐Methyl‐1H‐imidazo[4,5‐f]quinolin‐6‐ium chloride monohydrate

The title compound, C₁₁H₁₀N₃⁺·Cl^?·H₂O, belongs to the N1‐methyl‐substituted imidazo­[4,5‐f]­quinoline family, in which the heterocyclic ring is protonated at the pyridine rather than at the imidazole N atom. The mol­ecule as a whole is almost exactly planar. The molecular structure has been compared with that of the 2‐amino analogue described in the literature, and it was found that the extra amino group of the latter is involved in conjugation with the adjacent double bond, i.e. the conjugation does not extend over the entire heterocyclic system. The cation of the title compound forms a strong hydrogen bond with the Cl^? anion and the anions are interconnected by the water solvent mol­ecule.     

2,6‐Dimethyl‐1,4‐benzoquinone 4‐monooxime

Mol­ecules of the title compound, C₈H₉NO₂, are linked into sheets by a combination of C—H·N, O—H·N and O—H·O hydrogen bonds and C—H·π inter­actions. The hydrogen bonds are arranged as described by the graph‐set ring notations R₂²(7) and R₃³(5), and a C8 chain motif. There are two planar symmetry‐independent mol­ecules in the asymmetric unit, with a dihedral angle of 19.24 (5)° between their least‐squares mean planes.     

2‐Amino‐5‐chloro‐1,3‐benzoxazol‐3‐ium 2‐(3,4‐di­chloro­phenoxy)­acetate

The 1:1 organic salt of the title compound, C₇H₆ClN₂O⁺·C₈H₅Cl₂O₃^? or [(2‐ABOX)(3,4‐D)], comprises the two constituent mol­ecules associated by an R₂²(8) graph‐set interaction through the carboxyl­ate group of 3,4‐D across the protonated N/N sites of 2‐ABOX [N?O 2.546 (3) and 2.795 (3) Å]. Cation/anion pairs associate across an inversion centre forming discrete tetramers via an additional three‐centre hydrogen‐bonding association from the latter N amino proton to a phenoxy O atom [N?O 3.176 (3) Å] and a carboxyl­ate O atom [N?O 2.841 (3) Å]. This formation differs from the polymeric hydrogen‐bonded chains previously observed for adduct structures of 2‐ABOX with carboxyl­ic acids.     

4,7‐Bis(4‐pyridyl­ethynyl)‐2,1,3‐benzo­thia­diazo­le and its dipyridinium diperchlorate

The title compound, C₂₀H₁₀N₄S, and its dipyridinium salt, 4,4′‐(2,1,3‐benzo­diazol‐4,7‐diyl­diethynyl)­dipyridinium diperchlorate, C₂₀H₁₂N₄S²⁺·2ClO₄^?, display bond alternation in the 2,1,3‐benzo­thia­diazo­le rings, which suggests their quinonoid character. The dipyridinium dication mol­ecules stack along the a axis and form a dimer with short S?N interheteroatom contacts [3.146 (4) Å] between the two 1,2,5‐thia­diazo­le rings. The dimer is surrounded by the perchlorate anions with which it forms a large number of intermolecular N—H?O and C—H?O hydrogen bonds.