7,8‐Dihydr­oxy‐4‐propyl‐1,2,3,4,4a,5,6,10b‐octa­hydro­benzo[f]quinolinium bromide monohydrate,a dopamine agonist

In the crystal structure of the title dopamine­rgic compound, C₁₆H₂₄NO₂⁺·Br⁻·H₂O, protonation occurs at the piperidine N atom. The piperidine ring adopts a chair conformation and the cyclo­hexene ring adopts a half‐chair conformation; together with the planar benzene ring, this results in a relatively planar shape for the whole mol­ecule. Classical hydrogen bonds (N—H⋯Br, O—H⋯Br and O—H⋯O) produce an infinite three‐dimensional network. Hydrogen bonds between water ­mol­ecules and Br⁻ anions create centrosymmetric rings throughout the crystal structure. Structural comparison of the mol­ecule with the ergoline dopamine agonist pergolide shows that it is the hydrogen‐bond‐forming hydr­oxy or imino group that is necessary for dopamine­rgic activity, rather than the presence of a phenyl or a pyrrole ring per se.     

Picolinamidium squarate and di‐p‐toluidinium squarate dihydrate

The crystal structure determinations of picolinamidium squarate, C₆H₇N₂O⁺·C₄O₄⁻, (I), and di‐p‐toluidinium squarate dihydrate, 2C₇H₁₀N⁺·C₄O₄²⁻·2H₂O, (II), are reported. While salt formation occurs by donation of one H atom from squaric acid to the picolin­amide mol­ecule in (I), in compound (II), each squaric acid mol­ecule donates one H atom to the p‐toluidine N atom of two trans p‐toluidine molecules. In (I), the pyridine ring is coplanar with the squarate monoanion through imposed crystallographic mirror symmetry; in (II), the dihedral angle between the p‐toluidine moiety and the squarate dianion is 70.71 (1)°. In (I), a three‐dimensional structure is formed via van der Waals interactions between parallel planes of mol­ecules, with hydrogen‐bond interactions (N—H⋯O and O—H⋯O) acting within the planes; hydrogen bonds form a three‐dimensional network in (II).     

Moxifloxacinium chloride–water–methanol (2/1/1), a novel anti­bacterial agent

Moxifloxacin, a novel fluoro­quinolone with a broad spectrum of anti­bacterial activity, is available as the solvated monohydro­chloride salt 7‐[(S,S)‐2‐aza‐8‐azoniabicyclo­[4.3.0]non‐8‐yl]‐1‐cyclo­propyl‐6‐fluoro‐8‐meth­oxy‐4‐oxo‐1,4‐dihydroquinoline‐3‐carboxylic acid chloride–water–methanol (2/1/1), C₂₁H₂₅FN₃O₄⁺·Cl⁻·0.5H₂O·0.5CH₃OH. The asymmetric unit contains two cations, two chloride ions, a mol­ecule of water and one methanol mol­ecule. The two cations adopt conformations that differ by an almost 180° rotation with respect to the piperidinopyrrolidine side chain. The cyclo­propyl ring and the meth­oxy group are not coplanar with the quinoline ring system. The carboxylic acid function, the protonated terminal piperidyl N atom, the water mol­ecule, the chloride ion and the methanol mol­ecule participate in O—H⋯O, O—H⋯Cl, N—H⋯O and N—H⋯Cl hydrogen bonding, linking the mol­ecules into extended two‐dimensional networks.     

fac‐Bromo­tri­carbonyl­[2‐(2‐pyridylmethyl)‐2,3‐di­hydro‐1H‐isoindol‐1‐one]­rhenium(I) methanol solvate

The structure of the title compound, fac‐[ReBr(C₁₄H₁₂N₂O)(CO)₃]·CH₄O, consists of neutral mononuclear mol­ecular units of distorted octahedral geometry, with the three carbonyl donors in a facial orientation. The remaining coordination sites are occupied by the Br atom, the pyridine N atom and the ketone O‐atom donor of the ligand. The mol­ecules pack in stacks of antiparallel tapes, with a network of classical (O—H⋯Br) and non‐classical (C—H⋯O) hydrogen bonds between the methanol solvent mol­ecule and the complex mol­ecule.     

Aqua­(phthalocyaninato)magnesium n‐propyl­amine disolvate

The crystals of the title compound, [Mg(C₃₂H₁₆N₈)(H₂O)]·2C₃H₉N, are built up from MgPc(H₂O) [Pc is phthalo­cyaninate(2−)] and n‐propyl­amine mol­ecules that inter­act via O—H⋯N hydrogen bonds. The MgPc(H₂O) mol­ecule is non‐planar. The central Mg atom is coordinated by the four equatorial isoindole N atoms of the Pc ring system and by the O atom of an axial water mol­ecule. The Mg atom is displaced by 0.509 (1) Å from the N₄ plane towards the water O atom. MgPc(H₂O)·2(n‐propyl­amine) mol­ecules related by the inversion centre are linked by N—H⋯O hydrogen bonds to form a dimeric aggregate.     

N—H⋯N and C—H⋯π inter­actions in 4‐amino‐3‐methyl‐5‐(p‐tol­yl)‐4H‐1,2,4‐triazole and 4‐amino‐3‐methyl‐5‐phenyl‐4H‐1,2,4‐triazole

The title compounds, C₁₀H₁₂N₄, (I), and C₉H₁₀N₄, (II), have been synthesized and characterized both spectroscopically and structurally. The dihedral angles between the triazole and benzene ring planes are 26.59 (9) and 42.34 (2)°, respectively. In (I), mol­ecules are linked principally by N—H⋯N hydrogen bonds involving the amino NH₂ group and a triazole N atom, forming R₄⁴(20) and R₂⁴(10) rings which link to give a three‐dimensional network of mol­ecules. The hydrogen bonding is supported by two different C—H⋯π inter­actions from the tolyl ring to either a triazole ring or a tolyl ring in neighboring mol­ecules. In (II), inter­molecular hydrogen bonds and C—H⋯π inter­actions produce R₃⁴(15) and R₄⁴(21) rings.     

N‐(3H‐Thia­zol‐2‐yl­idene)­nitr­amine and N‐methyl‐N‐(thia­zol‐2‐yl)­nitr­amine

The geometries of the thia­zole ring and the nitr­amino groups in N‐(3H‐thia­zol‐2‐yl­idene)­nitr­amine, C₃H₃N₃O₂S, (I), and N‐­methyl‐N‐(thia­zol‐2‐yl)­nitr­amine, C₄H₅N₃O₂S, (II), are very similar. The nitr­amine group in (II) is planar and twisted along the C—N bond with respect to the thia­zole ring. In both structures, the asymmetric unit includes two practically equal mol­ecules. In (I), the mol­ecules are arranged in layers connected to each other by N—H⋯N and much weaker C—H⋯O hydrogen bonds. In the crystal structure of (II), the mol­ecules are arranged in layers bound to each other by both weak C—H⋯O hydrogen bonds and S⋯O dipolar interactions.     

Dichloro­(O‐ethyl 3‐methyl­pyridine‐2‐carboximidic acid‐κ2N,N′)copper(II)

In the title compound, [CuCl₂(C₉H₁₂N₂O)], the Cu^II atom is coordinated by two Cl⁻ anions and two N atoms of one O‐ethyl 3‐methyl­pyridine‐2‐carboximidic acid mol­ecule in a slightly distorted square‐planar geometry, with Cu—N distances of 2.0483 (17) and 1.9404 (18) Å, and Cu—Cl distances of 2.2805 (10) and 2.2275 (14) Å. In addition, each Cu^II atom is connected by one Cl⁻ anion and the Cu^II atom from a neighbouring mol­ecule, with Cu⋯Cl and Cu⋯Cu distances of 2.9098 (13) and 3.4022 (12) Å, respectively, and, therefore, a centrosymmetric dimer is formed. Adjacent mol­ecular dimers are connected by π–π stacking inter­actions between pyridine rings to form a zigzag mol­ecular chain. The mol­ecular chains are also enforced by N—H⋯Cl and C—H⋯Cl inter­actions.     

Polymorphism and solvolysis of 2‐cyano‐3‐[4‐(N,N‐diethyl­amino)­phenyl]­prop‐2‐ene­thio­amide

Two new polymorph forms, (Ia) and (Ib), of the title compound, C₁₄H₁₇N₃S, and its solvate with aceto­nitrile, C₁₄H₁₇N₃S·0.25C₂H₃N, (Ic), have been investigated. Crystals of the two polymorphs were grown from different solvents, viz. ethanol and N,N‐di­methyl­form­amide, respectively. The polymorphs have different orientations of the thio­amide group relative to the CN substituent, with s‐cis and s‐trans geometry of the C=C—C=S diene fragment, respectively. Compound (Ic) contains two independent mol­ecules, A and B, with s‐cis geometry, and the solvate mol­ecule lies on a twofold axis. The core of each mol­ecule is slightly non‐planar; the dihedral angles between the conjugated C=C—CN linkage and the phenyl ring, and between this linkage and the thio­amide group are 13.4 (2) and 12.0 (2)° in (Ia), 14.0 (2) and 18.2 (2)° in (Ib), 2.3 (3) and 12.7 (4)° in molecule A of (Ic), and 23.2 (3) and 8.1 (4)° in molecule B of (Ic). As a result of strong conjugation between donor and acceptor parts, the substituted phenyl rings have noticeable quinoid character. In (Ib), there exists a very strong intramolecular steric interaction (H⋯H = 1.95 Å) between the bridging and thio­amide parts of the mol­ecule, which makes such a form less stable. In the crystal structure of (Ia), intermolecular N—H⋯N and N—H⋯S hydrogen bonds link mol­ecules into infinite tapes along the [10] direction. In (Ib), such intermolecular hydrogen bonds link mol­ecules into infinite (101) planes. In (Ic), intermolecular N—H⋯N hydrogen bonds link mol­ecules A and B into dimers, which are connected via N—H⋯S hydrogen bonds and form infinite chains along the c direction.     

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.     

Ferrocene compounds. XXXIV. 1′‐(tert‐Butoxycarbonylamino)ferrocene‐1‐carboxylic acid

Heteroannularly substituted ferrocene derivatives can act as model systems for various hydrogen‐bonded assemblies of biomol­ecules formed, for instance, by means of O—H⋯O and N—H⋯O hydrogen bonding. The crystal structure analysis of 1′‐(tert‐butoxy­carbonyl­amino)­ferrocene‐1‐carbox­ylic acid, [Fe(C₁₀H₁₄NO₂)(C₆H₅O₂)] or (C₅H₄COOH)Fe(C₅­H₄NHCOOC(CH₃)₃, reveals two independent mol­ecules within the asymmetric unit, and these are joined into discrete dimers by two types of intermolecular hydrogen bonds, viz. O—H⋯O and N—H⋯O. The –COOH and –NHCOOR groups are archetypes for dimer formation via two eight‐membered rings. The O—H⋯O hydrogen bonds [2.656 (3) and 2.663 (3) Å] form a cyclic carboxylic acid dimer motif. Another eight‐membered ring is formed by N—H⋯O hydrogen bonds [2.827 (3) and 2.854 (3) Å] between the N—H group and an O atom of another carbamoyl moiety. The dimers are assembled in a herring‐bone fashion in the bc plane.     

2‐Formyl­benzonitrile

The title compound, C₈H₅NO, has an intra­molecular O⋯CN contact involving an O⋯C distance of 2.797 (2) Å and a C—C—N bond angle of 174.5 (2)°, both indicative of a weak nucleophilic attack of the aldehyde O atom on the electrophilic C atom in the nitrile group. Calculations at the B3LYP density functional level using the 6–31G* basis set support this inter­pretation; natural bond‐order analysis indicates an n_O1→π delocalization energy of 6.3 kJ mol⁻¹. Similar results were obtained from density functional calculations on three related mol­ecules. The 2‐formyl­benzonitrile mol­ecules pack in sheets as a consequence of C—H⋯N and C—H⋯O hydrogen bonds.     

Tris(3,5‐di­methyl‐1H‐pyrazole‐1‐thio­carboxamidato‐κ2N2,N)­cobalt(III)

In the crystal structure of the title complex, [Co(C₆H₈N₃S)₃], the Co^III atom is octahedrally coordinated by three monodeprotonated bidentate 3,5‐di­methyl‐1H‐pyrazole‐1‐thio­carbox­amide ligands with two thio­carbox­amide N atoms in axial positions. The asymmetric unit contains two mol­ecules (A and B) and these mol­ecules are arranged in chains in an alternating fashion connected by N—H⋯S interactions.     

9‐(2‐Chloro­ethyl­amino)­acridine monohydrate and its precursor 9‐phenoxy­acridine

The title compounds, C₁₅H₁₃ClN₂·H₂O, (I), and C₁₉H₁₃NO, (II), form monoclinic crystals. Arranged in a `head‐to‐tail' manner, the mol­ecules of the amine form (I) lie along the b axis in layers that are linked by a network of hydrogen bonds involving the endocyclic N atom, the H atom at the exocyclic N atom and all the atoms of the solvent water mol­ecule. Molecules of (II), with the phenoxy group nearly perpendicular to the acridine moiety, are arranged in pairs related by a center of symmetry and stabilized via two C—H⋯N contacts; the latter are linked via a network of further C—H⋯N contacts and non‐specific dispersive interactions.     

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.     

Displaced π–π stacking and hydrogen bonds in 3‐bromo‐N‐(2‐hydroxy‐1,1‐di­methyl­ethyl)­benz­amide

The mol­ecules of the title compound, C₁₁H₁₄BrNO₂, are assembled into a two‐dimensional network by a combination of hydrogen bonds and stacking interactions. The phenyl rings are stacked along the c direction by displaced π–π interactions, forming a lipophilic layer. The aliphatic amide residues are interconnected along [100] by O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds, forming hydro­philic layers.     

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.     

N‐(2,4‐Dimethoxy­benzyl­idene­amino)­guanidinium dihydrogenphosphate

In the asymmetric unit of the title compound, C₁₀H₁₅N₄O₂⁺·H₂PO₄⁻, there are two protonated amino­guanidinium cations and two dihydrogenphosphate anions. The positive charge on the protonated amidine group is delocalized over the three C—N bonds in a manner similar to that found in guanidinium salts. The amino­guanidinium cations are found to be the E‐isomer structures. Intra­molecular inter­actions of the N—H⋯N type are observed, leading to the formation of five‐membered rings. Extensive networks of O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds stabilize the three‐dimensional network. In the crystal structure, π–π inter­actions between the benzene rings, with a distance of 3.778 (2) Å between the ring centroids, also affect the packing of the mol­ecules.     

6‐Phenyl‐3‐(4‐pyrid­yl)‐1,2,4‐triazolo[3,4‐b][1,3,4]thia­diazole

The title compound, C₁₄H₉N₅S, has been synthesized and characterized both spectroscopically and structurally. The triazolo–thia­diazole system, the pyridine ring and the phenyl ring are all planar. The plane of the triazolo–thia­diazole system forms dihedral angles of 1.53 (13) and 7.55 (12)° with the planes of the pyridine and phenyl rings, respectively. In the mol­ecule, there are two intra­molecular inter­actions of types C—H⋯N and C—H⋯S. Inter­molecular C—H⋯N inter­actions involving a phenyl CH group and a triazole N atom lead to the formation of a one‐dimensional chain. In the crystal structure, two types of π–π inter­actions affect the packing of the mol­ecules. In addition, there are inter­molecular non‐bonded S⋯N contacts of 2.870 (2) Å, which may cause steric hindrance.     

5‐Acetyl‐2‐amino‐6‐methyl‐4‐phenyl‐4H‐pyran‐3‐carbonitrile and 2‐amino‐5‐benzoyl‐6‐methyl‐4‐phenyl‐4H‐pyran‐3‐carbonitrile acetonitrile solvate

The syntheses, X‐ray structural investigations and calculations of the conformational preferences of the carbonyl substituent with respect to the pyran ring have been carried out for the two title compounds, viz. C₁₅H₁₄N₂O₂, (II), and C₂₀H₁₆N₂O₂·C₂H₃N, (III), respectively. In both mol­ecules, the heterocyclic ring adopts a flattened boat conformation. In (II), the carbonyl group and a double bond of the heterocyclic ring are syn, but in (III) they are anti. The carbonyl group forms a short contact with a methyl group H atom in (II). The dihedral angles between the pseudo‐axial phenyl substituent and the flat part of the pyran ring are 92.7 (1) and 93.2 (1)° in (II) and (III), respectively. In the crystal structure of (II), inter­molecular N—H⋯N and N—H⋯O hydrogen bonds link the mol­ecules into a sheet along the (103) plane, while in (III), they link the mol­ecules into ribbons along the a axis.