Three‐dimensional hydrogen‐bonded framework structures in flunarizinium nicotinate and flunarizinediium bis(4‐toluenesulfonate) dihydrate

The structures of two salts of flunarizine, namely 1‐bis[(4‐fluorophenyl)methyl]‐4‐[(2E)‐3‐phenylprop‐2‐en‐1‐yl]piperazine, C₂₆H₂₆F₂N₂, are reported. In flunarizinium nicotinate {systematic name: 4‐bis[(4‐fluorophenyl)methyl]‐1‐[(2E)‐3‐phenylprop‐2‐en‐1‐yl]piperazin‐1‐ium pyridine‐3‐carboxylate}, C₂₆H₂₇F₂N₂⁺·C₆H₄NO₂⁻, (I), the two ionic components are linked by a short charge‐assisted N—H...O hydrogen bond. The ion pairs are linked into a three‐dimensional framework structure by three independent C—H...O hydrogen bonds, augmented by C—H...π(arene) hydrogen bonds and an aromatic π–π stacking interaction. In flunarizinediium bis(4‐toluenesulfonate) dihydrate {systematic name: 1‐[bis(4‐fluorophenyl)methyl]‐4‐[(2E)‐3‐phenylprop‐2‐en‐1‐yl]piperazine‐1,4‐diium bis(4‐methylbenzenesulfonate) dihydrate}, C₂₆H₂₈F₂N₂²⁺·2C₇H₇O₃S⁻·2H₂O, (II), one of the anions is disordered over two sites with occupancies of 0.832 (6) and 0.168 (6). The five independent components are linked into ribbons by two independent N—H...O hydrogen bonds and four independent O—H...O hydrogen bonds, and these ribbons are linked to form a three‐dimensional framework by two independent C—H...O hydrogen bonds, but C—H...π(arene) hydrogen bonds and aromatic π–π stacking interactions are absent from the structure of (II). Comparisons are made with some related structures.     

Multiple hydrogen bonds in cytosinium zoledronate trihydrate

The asymmetric unit of the title compound [systematic name: 4‐amino‐2‐oxo‐2,3‐dihydropyrimidin‐1‐ium 1‐hydroxy‐2‐(1H,3H‐imidazol‐3‐ium‐1‐yl)ethylidenediphosphonate trihydrate], C₄H₆N₃O⁺·C₅H₉N₂O₇P₂⁻·3H₂O, contains one cytosinium cation, one zoledronate anion and three water molecules. The zoledronate anion has a zwitterionic character, in which each phosphonate group is singly deprotonated and an imidazole N atom is protonated. Furthermore, proton transfer takes place from one of the phosphonic acid groups of the zoledronate anion to one of the N atoms of the cytosinium cation. The cytosinium cation forms a C(6) chain, while the zoledronate anion forms a rectangular‐shaped centrosymmetric dimer through N—H...O hydrogen bonds. The cations and anions are held together by N—H...O and O—H...O hydrogen bonds to form a one‐dimensional polymeric tape. The three water molecules play a crucial role in hydrogen bonding, resulting in a three‐dimensional hydrogen‐bonded network.     

5‐Formylsalicylic acid and 5‐(benzimidazolium‐2‐yl)salicylate

Both title compounds are derivatives of salicylic acid. 5‐Formylsalicylic acid (systematic name: 5‐formyl‐2‐hydroxybenzoic acid), C₈H₆O₄, possesses three good hydrogen‐bond donors and/or acceptors coplanar with their attached benzene ring and abides very well by Etter's hydrogen‐bond rules. Intermolecular O—H...O and some weak C—H...O hydrogen bonds link the molecules into a planar sheet. Reaction of this acid and o‐phenylenediamine in refluxing ethanol produced in high yield the new zwitterionic compound 5‐(benzimidazolium‐2‐yl)salicylate [systematic name: 5‐(1H‐benzimidazol‐3‐ium‐2‐yl)‐2‐hydroxybenzoate], C₁₄H₁₀N₂O₃. Each imidazolium N—H group and its adjacent salicyl C—H group chelate one carboxylate O atom via hydrogen bonds, forming seven‐membered rings. As a result of steric hindrance, the planes of the molecules within these pairs of hydrogen‐bonded molecules are inclined to one another by ∼74°. There are also π–π stacking interactions between the parallel planes of the imidazole ring and the benzene ring of the salicyl component of the adjacent molecule on one side and the benzimidazolium component of the molecule on the other side.     

Conformations and resulting hydrogen‐bonded networks of hydrogen {phosphono[(pyridin‐1‐ium‐3‐yl)amino]methyl}phosphonate and related 2‐chloro and 6‐chloro derivatives

In the crystal structures of the conformational isomers hydrogen {phosphono[(pyridin‐1‐ium‐3‐yl)amino]methyl}phosphonate monohydrate (pro‐E), C₆H₁₀N₂O₆P₂·H₂O, (Ia), and hydrogen {phosphono[(pyridin‐1‐ium‐3‐yl)amino]methyl}phosphonate (pro‐Z), C₆H₁₀N₂O₆P₂, (Ib), the related hydrogen {[(2‐chloropyridin‐1‐ium‐3‐yl)amino](phosphono)methyl}phosphonate (pro‐E), C₆H₉ClN₂O₆P₂, (II), and the salt bis(6‐chloropyridin‐3‐aminium) [hydrogen bis({[2‐chloropyridin‐1‐ium‐3‐yl(0.5+)]amino}methylenediphosphonate)] (pro‐Z), 2C₅H₆ClN₂⁺·C₁₂H₁₆Cl₂N₄O₁₂P₄²⁻, (III), chain–chain interactions involving phosphono (–PO₃H₂) and phosphonate (–PO₃H⁻) groups are dominant in determining the crystal packing. The crystals of (Ia) and (III) comprise similar ribbons, which are held together by N—H...O interactions, by water‐ or cation‐mediated contacts, and by π–π interactions between the aromatic rings of adjacent zwitterions in (Ia), and those of the cations and anions in (III). The crystals of (Ib) and (II) have a layered architecture: the former exhibits highly corrugated monolayers perpendicular to the [100] direction, while in the latter, flat bilayers parallel to the (001) plane are formed. In both (Ib) and (II), the interlayer contacts are realised through N—H...O hydrogen bonds and weak C—H...O interactions involving aromatic C atoms.     

Six closely related 4,6‐disubstituted 2‐amino‐5‐formylpyrimidines: different ring conformations,polarized electronic structures,and hydrogen‐bonded assembly in zero,one, two and three dimensions

In each of ethyl N‐{2‐amino‐5‐formyl‐6‐[methyl(phenyl)amino]pyrimidin‐4‐yl}glycinate, C₁₆H₁₉N₅O₃, (I), N‐{2‐amino‐5‐formyl‐6‐[methyl(phenyl)amino]pyrimidin‐4‐yl}glycinamide, C₁₄H₁₆N₆O₂, (II), and ethyl 3‐amino‐N‐{2‐amino‐5‐formyl‐6‐[methyl(phenyl)amino]pyrimidin‐4‐yl}propionate, C₁₇H₂₁N₅O₃, (III), the pyrimidine ring is effectively planar, but in each of methyl N‐{2‐amino‐6‐[benzyl(methyl)amino]‐5‐formylpyrimidin‐4‐yl}glycinate, C₁₆H₁₉N₅O₃, (IV), ethyl 3‐amino‐N‐{2‐amino‐6‐[benzyl(methyl)amino]‐5‐formylpyrimidin‐4‐yl}propionate, C₁₈H₂₃N₅O₃, (V), and ethyl 3‐amino‐N‐[2‐amino‐5‐formyl‐6‐(piperidin‐4‐yl)pyrimidin‐4‐yl]propionate, C₁₅H₂₃N₅O₃, (VI), the pyrimidine ring is folded into a boat conformation. The bond lengths in each of (I)–(VI) provide evidence for significant polarization of the electronic structure. The molecules of (I) are linked by paired N—H...N hydrogen bonds to form isolated dimeric aggregates, and those of (III) are linked by a combination of N—H...N and N—H...O hydrogen bonds into a chain of edge‐fused rings. In the structure of (IV), molecules are linked into sheets by means of two hydrogen bonds, both of N—H...O type, in the structure of (V) by three hydrogen bonds, two of N—H...N type and one of C—H...O type, and in the structure of (VI) by four hydrogen bonds, all of N—H...O type. Molecules of (II) are linked into a three‐dimensional framework structure by a combination of three N—H...O hydrogen bonds and one C—H...O hydrogen bond.     

Water‐induced pseudo‐quadruple hydrogen‐bonding motifs in xanthine–inorganic acid complexes

In xanthinium nitrate hydrate [systematic name: 2,6‐dioxo‐1,2,3,6‐tetrahydro‐9H‐purin‐7‐ium nitrate monohydrate], C₅H₅N₄O₂⁺·NO₃⁻·H₂O, (I), and xanthinium hydrogen sulfate hydrate [systematic name: 2,6‐dioxo‐1,2,3,6‐tetrahydro‐9H‐purin‐7‐ium hydrogen sulfate monohydrate], C₅H₅N₄O₂⁺·HSO₄⁻·H₂O, (II), the xanthine molecules are protonated at the imine N atom with the transfer of an H atom from the inorganic acid. The asymmetric unit of (I) contains a xanthinium cation, a nitrate anion and one water molecule, while that of (II) contains two crystallographically independent xanthinium cations, two hydrogen sulfate anions and two water molecules. A pseudo‐quadruple hydrogen‐bonding motif is formed between the xanthinium cations and the water molecules via N—H...O and O—H...O hydrogen bonds in both structures, and leads to the formation of one‐dimensional polymeric tapes. These cation–water tapes are further connected by the respective anions and aggregate into two‐dimensional hydrogen‐bonded sheets in (I) and three‐dimensional arrangements in (II).     

1‐Carboxymethyl‐3‐methyl‐1H‐imidazol‐3‐ium chloride 2‐(3‐methyl‐1H‐imidazol‐3‐ium‐1‐yl)acetate monohydrate: a crystal stabilized by imidazolium zwitterions

The title compound, C₆H₉N₂O₂⁺·Cl⁻·C₆H₈N₂O₂·H₂O, contains one 2‐(3‐methyl‐1H‐imidazol‐3‐ium‐1‐yl)acetate inner salt molecule, one 1‐carboxymethyl‐3‐methyl‐1H‐imidazol‐3‐ium cation, one chloride ion and one water molecule. In the extended structure, chloride anions and water molecules are linked via O—H...Cl hydrogen bonds, forming an infinite one‐dimensional chain. The chloride anions are also linked by two weak C—H...Cl interactions to neighbouring methylene groups and imidazole rings. Two imidazolium moieties form a homoconjugated cation through a strong and asymmetric O—H...O hydrogen bond of 2.472 (2) Å. The IR spectrum shows a continuous D‐type absorption in the region below 1300 cm⁻¹ and is different to that of 1‐carboxymethyl‐3‐methylimidazolium chloride [Xuan, Wang & Xue (2012). Spectrochim. Acta Part A, 96 , 436–443].     

The inner‐salt zwitterion,the dihydrochloride dihydrate and the dimethyl sulfoxide disolvate of 3,6‐bis(pyridin‐2‐yl)pyrazine‐2,5‐dicarboxylic acid

In the inner‐salt zwitterion of 3,6‐bis(pyridin‐2‐yl)pyrazine‐2,5‐dicarboxylic acid, (I), namely 5‐carboxy‐3‐(pyridin‐1‐ium‐2‐yl)‐6‐(pyridin‐2‐yl)pyrazine‐2‐carboxylate, [C₁₆H₁₀N₄O₄, (Ia)], the pyrazine ring has a twist–boat conformation. The opposing pyridine and pyridinium rings are almost perpendicular to one another, with a dihedral angle of 80.24 (18)°, and are inclined to the pyrazine mean plane by 36.83 (17) and 43.74 (17)°, respectively. The carboxy and carboxylate groups are inclined to the mean plane of the pyrazine ring by 43.60 (17) and 45.46 (17)°, respectively. In the crystal structure, the molecules are linked via N—H...O and O—H...O hydrogen bonds, leading to the formation of double‐stranded chains propagating in the [010] direction. On treating (Ia) with aqueous 1 M HCl, the diprotonated dihydrate form 2,2′‐(3,6‐dicarboxypyrazine‐2,5‐diyl)bis(pyridin‐1‐ium) dichloride dihydrate [C₁₆H₁₂N₄O₄²⁺·2Cl⁻·2H₂O, (Ib)] was obtained. The cation lies about an inversion centre. The pyridinium rings and carboxy groups are inclined to the planar pyrazine ring by 55.53 (9) and 19.8 (2)°, respectively. In the crystal structure, the molecules are involved in N—H...Cl, O—H...O_water and O_water—H...Cl hydrogen bonds, leading to the formation of chains propagating in the [010] direction. When (Ia) was recrystallized from dimethyl sulfoxide (DMSO), the DMSO disolvate 3,6‐bis(pyridin‐2‐yl)pyrazine‐2,5‐dicarboxylic acid dimethyl sulfoxide disolvate [C₁₆H₁₀N₄O₄·2C₂H₆OS, (Ic)] of (I) was obtained. Here, the molecule of (I) lies about an inversion centre and the pyridine rings are inclined to the planar pyrazine ring by only 23.59 (12)°. However, the carboxy groups are inclined to the pyrazine ring by 69.0 (3)°. In the crystal structure, the carboxy groups are linked to the DMSO molecules by O—H...O hydrogen bonds. In all three crystal structures, the presence of nonclassical hydrogen bonds gives rise to the formation of three‐dimensional supramolecular architectures.     

Hydrogen‐bonded sheet structures in neutral,anionic and hydrated 6‐amino‐2‐(morpholin‐4‐yl)‐5‐nitrosopyrimidines

In each of 6‐amino‐3‐methyl‐2‐(morpholin‐4‐yl)‐5‐nitrosopyrimidin‐4(3H)‐one, C₉H₁₃N₅O₃, (I), morpholin‐4‐ium 4‐amino‐2‐(morpholin‐4‐yl)‐5‐nitroso‐6‐oxo‐1,6‐dihydropyrimidin‐1‐ide, C₄H₁₀NO⁺·C₈H₁₀N₅O₃⁻, (II), and 6‐amino‐2‐(morpholin‐4‐yl)‐5‐nitrosopyrimidin‐4(3H)‐one hemihydrate, C₈H₁₁N₅O₃·0.5H₂O, (III), the bond distances within the pyrimidine components are consistent with significant electronic polarization, which is most marked in (II) and least marked in (I). Despite the high level of substitution, the pyrimidine rings are all effectively planar, and in each of the pyrimidine components, there are intramolecular N—H...O hydrogen bonds. In each compound, the organic components are linked by multiple N—H...O hydrogen bonds to form sheets of widely differing construction, and in compound (III) adjacent sheets are linked by the water molecules, so forming a three‐dimensional hydrogen‐bonded framework. This study also contains the first direct geometric comparison between the electronic polarization in a neutral aminonitrosopyrimidine and that in its ring‐deprotonated conjugate anion in a metal‐free environment.     

Dihydrooxazolones and dihydroimidazolones derived from acylglycines: syntheses,molecular structures and supramolecular assembly

Syntheses and structures are described for some alkylidene‐substituted dihydrooxazolones and dihydroimidazoles derived from simple acylglycines. A second, triclinic, polymorph of 4‐benzylidene‐2‐(4‐methylphenyl)‐1,3‐oxazol‐5(4H)‐one, C₁₇H₁₃NO₂, (I), has been identified and the structure of 2‐methyl‐4‐[(thiophen‐2‐yl)methylidene]‐1,3‐oxazol‐5(4H)‐one, C₉H₇NO₂S, (II), has been rerefined taking into account the orientational disorder of the thienyl group in each of the two independent molecules. The reactions of phenylhydrazine with 2‐phenyl‐4‐[(thiophen‐2‐yl)methylidene]‐1,3‐oxazol‐5(4H)‐one or 2‐(4‐methylphenyl)‐4‐[(thiophen‐2‐yl)methylidene]‐1,3‐oxazol‐5(4H)‐one yield, respectively, 3‐anilino‐2‐phenyl‐5‐[(thiophen‐2‐yl)methylidene]‐3,5‐dihydro‐4H‐imidazol‐4‐one, C₁₀H₁₅N₃OS, (III), and 3‐anilino‐2‐(4‐methylphenyl)‐5‐[(thiophen‐2‐yl)methylidene]‐3,5‐dihydro‐4H‐imidazol‐4‐one, C₂₁H₁₇N₃OS, (IV), which both exhibit orientational disorder in their thienyl groups. The reactions of 2‐phenyl‐4‐[(thiophen‐2‐yl)methylidene]‐1,3‐oxazol‐5(4H)‐one with hydrazine hydrate or with water yield, respectively, N‐[3‐hydrazinyl‐3‐oxo‐1‐(thiophen‐2‐yl)prop‐1‐en‐2‐yl]benzamide and 2‐(benzoylamino)‐3‐(thiophen‐2‐yl)prop‐2‐enoic acid, which in turn react, respectively, with thiophene‐2‐carbaldehyde to form 2‐phenyl‐5‐[(thiophen‐2‐yl)methylidene]‐3‐{[(E)‐(thiophen‐2‐yl)methylidene]amino}‐3,5‐dihydro‐4H‐imidazol‐4‐one, C₁₉H₁₃N₃OS₂, (V), which exhibits orientational disorder in only one of its thienyl groups, and with methanol to give methyl (2Z)‐2‐(benzoylamino)‐3‐(thiophen‐2‐yl)prop‐2‐enoate, C₁₅H₁₃NO₃S, (VI). There are no direction‐specific intermolecular interactions in the crystal structure of the triclinic polymorph of (I), but the molecules of (II) are linked by two independent C—H...O hydrogen bonds to form C₂²(14) chains. Compounds (III) and (IV) both form centrosymmetric R₂²(10) dimers built from N—H...O hydrogen bonds, while compound (V) forms a centrosymmetric R₂²(10) dimer built from C—H...O hydrogen bonds. In the structure of compound (VI), a combination of N—H...O and C—H...π(arene) hydrogen bonds links the molecules into sheets. Comparisons are made with some similar compounds.     

Hydrogen‐bonding patterns in three substituted N‐benzyl‐N‐(3‐tert‐butyl‐1‐phenyl‐1H‐pyrazol‐5‐yl)acetamides

The molecules of N‐(3‐tert‐butyl‐1‐phenyl‐1H‐pyrazol‐5‐yl)‐2‐chloro‐N‐(4‐methoxybenzyl)acetamide, C₂₃H₂₆ClN₃O₂, are linked into a chain of edge‐fused centrosymmetric rings by a combination of one C—H...O hydrogen bond and one C—H...π(arene) hydrogen bond. In N‐(3‐tert‐butyl‐1‐phenyl‐1H‐pyrazol‐5‐yl)‐2‐chloro‐N‐(4‐chlorobenzyl)acetamide, C₂₂H₂₃Cl₂N₃O, a combination of one C—H...O hydrogen bond and two C—H...π(arene) hydrogen bonds, which utilize different aryl rings as the acceptors, link the molecules into sheets. The molecules of S‐[N‐(3‐tert‐butyl‐1‐phenyl‐1H‐pyrazol‐5‐yl)‐N‐(4‐methylbenzyl)carbamoyl]methyl O‐ethyl carbonodithioate, C₂₆H₃₁N₃O₂S₂, are also linked into sheets, now by a combination of two C—H...O hydrogen bonds, both of which utilize the amide O atom as the acceptor, and two C—H...π(arene) hydrogen bonds, which utilize different aryl groups as the acceptors.     

4‐(3‐Azaniumylpropyl)morpholin‐4‐ium chloride hydrogen oxalate: an unusual example of a dication with different counter‐anions

The mixed organic–inorganic title salt, C₇H₁₈N₂O²⁺·C₂HO₄⁻·Cl⁻, forms an assembly of ionic components which are stabilized through a series of hydrogen bonds and charge‐assisted intermolecular interactions. The title assembly crystallizes in the monoclinic C2/c space group with Z = 8. The asymmetric unit consists of a 4‐(3‐azaniumylpropyl)morpholin‐4‐ium dication, a hydrogen oxalate counter‐anion and an inorganic chloride counter‐anion. The organic cations and anions are connected through a network of N—H...O, O—H...O and C—H...O hydrogen bonds, forming several intermolecular rings that can be described by the graph‐set notations R₃³(13), R₂¹(5), R₁²(5), R₂¹(6), R₂³(6), R₂²(8) and R₃³(9). The 4‐(3‐azaniumylpropyl)morpholin‐4‐ium dications are interconnected through N—H...O hydrogen bonds, forming C(9) chains that run diagonally along the ab face. Furthermore, the hydrogen oxalate anions are interconnected via O—H...O hydrogen bonds, forming head‐to‐tail C(5) chains along the crystallographic b axis. The two types of chains are linked through additional N—H...O and O—H...O hydrogen bonds, and the hydrogen oxalate chains are sandwiched by the 4‐(3‐azaniumylpropyl)morpholin‐4‐ium chains, forming organic layers that are separated by the chloride anions. Finally, the layered three‐dimensional structure is stabilized via intermolecular N—H...Cl and C—H...Cl interactions.     

Synthesis and characterization of a novel long‐alkyl‐chain ester‐substituted benzimidazole gelator and its octan‐1‐ol solvate

The synthesis of a novel benzimidazole derivative with a long‐chain‐ester substituent, namely methyl 8‐[4‐(1H‐benzimidazol‐2‐yl)phenoxy]octanoate, (3), is reported. Ester (3) shows evidence of aggregation in solution and weak gelation ability with toluene. The octan‐1‐ol solvate, methyl 8‐[4‐(1H‐benzimidazol‐2‐yl)phenoxy]octanoate octan‐1‐ol monosolvate, C₂₂H₂₆N₂O₃·C₈H₁₈O, (4), exhibits a four‐molecule hydrogen‐bonded motif in the solid state, with N—H…O hydrogen bonds between benzimidazole molecules and O—H…N hydrogen bonds between the octan‐1‐ol solvent molecules and the benzimidazole unit. The alkyl chains of the ester and the octan‐1‐ol molecules are in unfolded conformations. The phenylene ring is canted by 10.27 (6)° from the plane of the benzimidazole ring system. H…C contacts make up 20.7% of the Hirshfeld surface coverage. Weak C—H…π interactions involving the benzimidazole alkyl chain and three aromatic rings are observed.     

Three structures containing (E)‐1,2‐bis­(benzimidazol‐2‐yl)ethene groups

Two of the title compounds, namely (E)‐1,2‐bis­(1‐methyl­benzimidazol‐2‐yl)ethene, C₁₈H₁₆N₄, (Ib), and (E)‐1,2‐bis­(1‐ethyl­benzimidazol‐2‐yl)ethene, C₂₀H₂₀N₄, (Ic), consist of centrosymmetric trans‐bis­(1‐alkyl­benzimidazol‐2‐yl)ethene mol­ecules, while 3‐eth­yl‐2‐[(E)‐2‐(1‐ethyl­benzimidazol‐2‐yl)­ethen­yl]benzimidazol‐1‐ium perchlorate, C₂₀H₂₁N₄⁺·ClO₄⁻, (II), contains the monoprotonated analogue of compound (Ic). In the three structures, the benzimidazole and benzimidazolium moieties are essentially planar; the geometric parameters for the ethene linkages and their bonds to the aromatic groups are consistent with double and single bonds, respectively, implying little, if any, conjugation of the central C=C bonds with the nitro­gen‐containing rings. The C—N bond lengths in the N=C—N part of the benzimidazole groups differ and are consistent with localized imine C=N and amine C—N linkages in (Ib) and (Ic); in contrast, the corresponding distances in the benzimidazolium cation are equal in (II), consistent with electron delocalization resulting from protonation of the amine N atom. Crystals of (Ib) and (Ic) contain columns of parallel mol­ecules, which are linked by edge‐over‐edge C—H⋯π overlap. The columns are linked to one another by C—H⋯π inter­actions and, in the case of (Ib), C—H⋯N hydrogen bonds. Crystals of (II) contain layers of monocations linked by π–π inter­actions and separated by both perchlorate anions and the protruding eth­yl groups; the cations and anions are linked by N—H⋯O hydrogen bonds.     

Three new olanzapine structures: the acetic acid monosolvate,and the propan‐2‐ol and propan‐2‐one hemisolvate monohydrates

The crystal structures of three new solvates of olanzapine [systematic name: 2‐methyl‐4‐(4‐methylpiperazin‐1‐yl)‐10H‐thieno[2,3‐b][1,5]benzodiazepine], namely olanzapine acetic acid monosolvate, C₁₇H₂₀N₄S·C₂H₄O₂, (I), olanzapine propan‐2‐ol hemisolvate monohydrate, C₁₇H₂₀N₄S·0.5C₃H₈O·H₂O, (II), and olanzapine propan‐2‐one hemisolvate monohydrate, C₁₇H₂₀N₄S·0.5C₃H₆O·H₂O, (III), are presented and compared with other known olanzapine forms. There is a fairly close resemblance of the molecular conformation for all studied analogues. The crystal structures are built up through olanzapine dimers, which are characterized via C—H...π interactions between the aliphatic fragment (1‐methylpiperazin‐4‐yl) and the aromatic fragment (benzene system). All solvent (guest) molecules participate in hydrogen‐bonding networks. The crystal packing is sustained via intermolecular N_host—H...O_guest, O_guest—H...N_host, O_guest—H...O_guest and C_host—H...O_guest hydrogen bonds. It should be noted that the solvent propan‐2‐ol in (II) and propan‐2‐one in (III) show orientational disorder. The propan‐2‐ol molecule lies close to a twofold axis, while the propan‐2‐one molecule resides strictly on a twofold axis through the carbonyl C atom. In both cases, the water molecules present positional disorder of the H atoms.     

Geometry and bond‐length alternation in nonlinear optical materials. II. Effects of donor strength in two push–pull molecules

The compounds N‐[2‐(4‐cyano‐5‐dicyanomethylene‐2,2‐dimethyl‐2,5‐dihydrofuran‐3‐yl)vinyl]‐N‐phenylacetamide, C₂₀H₁₆N₄O₂,(I), and 2‐{3‐cyano‐5,5‐dimethyl‐4‐[2‐(piperidin‐1‐yl)vinyl]‐2,5‐dihydrofuran‐2‐ylidene}malononitrile 0.376‐hydrate, C₁₇H₁₈N₄O·0.376H₂O, (II), are novel push–pull molecules. The significant bonding changes in the polyene chain compared with the parent molecule 2‐dicyanomethylene‐4,5,5‐trimethyl‐2,5‐dihyrofuran‐3‐carbonitrile are consistent with the relative electron‐donating properties of the acetanilido and piperidine groups. The packing of (I) utilizes one phenyl–cyano C—H...N and two phenyl–carbonyl C—H...O hydrogen bonds. Compound (II) crystallizes with a partial water molecule (0.376H₂O), consistent with cell packing that is dominated by attractive C—H...N(cyano) interactions. These compounds are precursors to novel nonlinear optical chromophores, studied to assess the impact of donor strength and the extent of conjugation on bond‐length alternation, crystal packing and aggregation.     

Synthesis and structures of six closely related N‐[3‐(2‐chlorobenzoyl)‐5‐ethylthiophen‐2‐yl]arylamides,together with an isolated reaction intermediate: order versus disorder,molecular conformations and hydrogen bonding in zero,one and two dimensions

Six closely related N‐[3‐(2‐chlorobenzoyl)‐5‐ethylthiophen‐2‐yl]arylamides have been synthesized and structurally characterized, together with a representative reaction intermediate. In each of N‐[3‐(2‐chlorobenzoyl)‐5‐ethylthiophen‐2‐yl]benzamide, C₂₀H₁₆ClNO₂S, (I), N‐[3‐(2‐chlorobenzoyl)‐5‐ethylthiophen‐2‐yl]‐4‐phenylbenzamide, C₂₆H₂₀ClNO₂S, (II), and 2‐bromo‐N‐[3‐(2‐chlorobenzoyl)‐5‐ethylthiophen‐2‐yl]benzamide, C₂₀H₁₅BrClNO₂S, (III), the molecules are disordered over two sets of atomic sites, with occupancies of 0.894 (8) and 0.106 (8) in (I), 0.832 (5) and 0.168 (5) in (II), and 0.7006 (12) and 0.2994 (12) in (III). In each of N‐[3‐(2‐chlorobenzoyl)‐5‐ethylthiophen‐2‐yl]‐2‐iodobenzamide, C₂₀H₁₅ClINO₂S, (IV), and N‐[3‐(2‐chlorobenzoyl)‐5‐ethylthiophen‐2‐yl]‐2‐methoxybenzamide, C₂₁H₁₈ClNO₃S, (V), the molecules are fully ordered, but in N‐[3‐(2‐chlorobenzoyl)‐5‐ethylthiophen‐2‐yl]‐2,6‐difluorobenzamide, C₂₀H₁₄ClF₂NO₂S, (VI), which crystallizes with Z′ = 2 in the space group C2/c, one of the two independent molecules is fully ordered, while the other is disordered over two sets of atomic sites having occupancies of 0.916 (3) and 0.084 (3). All of the molecules in compounds (I)–(VI) exhibit an intramolecular N—H…O hydrogen bond. The molecules of (I) and (VI) are linked by C—H…O hydrogen bonds to form finite zero‐dimensional dimers, which are cyclic in (I) and acyclic in (VI), those of (III) are linked by C—H…π(arene) hydrogen bonds to form simple chains, and those of (IV) and (V) are linked into different types of chains of rings, built in each case from a combination of C—H…O and C—H…π(arene) hydrogen bonds. Two C—H…O hydrogen bonds link the molecules of (II) into sheets containing three types of ring. In benzotriazol‐1‐yl 3,4‐dimethoxybenzoate, C₁₅H₁₃N₃O₄, (VII), the benzoate component is planar and makes a dihedral angle of 84.51 (6)° with the benzotriazole unit. Comparisons are made with related compounds.     

Supramolecular aggregation in three 4‐aryl‐6‐(1H‐indol‐3‐yl)‐3‐methyl‐1‐phenyl‐1H‐pyrazolo[3,4‐b]pyridine‐5‐carbonitriles

Both 6‐(1H‐indol‐3‐yl)‐3‐methyl‐4‐(4‐methylphenyl)‐1‐phenyl‐1H‐pyrazolo[3,4‐b]pyridine‐5‐carbonitrile and 6‐(1H‐indol‐3‐yl)‐3‐methyl‐4‐(4‐methoxyphenyl)‐1‐phenyl‐1H‐pyrazolo[3,4‐b]pyridine‐5‐carbonitrile crystallize from dimethylformamide solutions as stoichiometric 1:1 solvates, viz. C₂₉H₂₁N₅·C₃H₇NO, (I), and C₂₉H₂₁N₅O·C₃H₇NO, (II), respectively; however, 6‐(1H‐indol‐3‐yl)‐3‐methyl‐1‐phenyl‐4‐(3,4,5‐trimethoxyphenyl)‐1H‐pyrazolo[3,4‐b]pyridine‐5‐carbonitrile, C₃₁H₂₅N₅O₃, (III), crystallizes in the unsolvated form. The heterocyclic components of (I) are linked by C—H...π(arene) hydrogen bonds to form cyclic centrosymmetric dimers, from which the solvent molecules are pendent, linked by N—H...O hydrogen bonds. In (II), the heterocyclic components are linked by a combination of C—H...N and C—H...π(arene) hydrogen bonds into chains containing two types of centrosymmetric ring, and the pendent solvent molecules are linked to these chains by N—H...O hydrogen bonds. Molecules of (III) are linked into simple C(12) chains by an N—H...O hydrogen bond, and these chains are weakly linked into pairs by an aromatic π–π stacking interaction.     

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.     

Comparison of the hydrogen‐bond patterns in 2‐amino‐1,3,4‐thiadiazolium hydrogen oxalate, 2‐amino‐1,3,4‐thiadiazole–succinic acid (1/2), 2‐amino‐1,3,4‐thiadiazole–glutaric acid (1/1) and 2‐amino‐1,3,4‐thiadiazole–adipic acid (1/1)

The X‐ray single‐crystal structure determinations of the chemically related compounds 2‐amino‐1,3,4‐thiadiazolium hydrogen oxalate, C₂H₄N₃S⁺·C₂HO₄⁻, (I), 2‐amino‐1,3,4‐thiadiazole–succinic acid (1/2), C₂H₃N₃S·2C₄H₆O₄, (II), 2‐amino‐1,3,4‐thiadiazole–glutaric acid (1/1), C₂H₃N₃S·C₅H₈O₄, (III), and 2‐amino‐1,3,4‐thiadiazole–adipic acid (1/1), C₂H₃N₃S·C₆H₁₀O₄, (IV), are reported and their hydrogen‐bonding patterns are compared. The hydrogen bonds are of the types N—H...O or O—H...N and are of moderate strength. In some cases, weak C—H...O interactions are also present. Compound (II) differs from the others not only in the molar ratio of base and acid (1:2), but also in its hydrogen‐bonding pattern, which is based on chain motifs. In (I), (III) and (IV), the most prominent feature is the presence of an R₂²(8) graph‐set motif formed by N—H...O and O—H...N hydrogen bonds, which are present in all structures except for (I), where only a pair of N—H...O hydrogen bonds is present, in agreement with the greater acidity of oxalic acid. There are nonbonding S...O interactions present in all four structures. The difference electron‐density maps show a lack of electron density about the S atom along the S...O vector. In all four structures, the carboxylic acid H atoms are present in a rare configuration with a C—C—O—H torsion angle of ∼0°. In the structures of (II)–(IV), the C—C—O—H torsion angle of the second carboxylic acid group has the more common value of ∼|180|°. The dicarboxylic acid molecules are situated on crystallographic inversion centres in (II). The Raman and IR spectra of the title compounds are presented and analysed.