Racemic cis-bis-[bis-(pyrimidin-2-yl)amine-κN]bis(dicyanamido-κN1)iron(II) dihydrate: synthesis, crystal structure and Hirshfeld surface analysis.

The title compound, [Fe(C2N3)2(C8H7N5)2]·2H2O, has been synthesized solvothermally and characterized by single-crystal X-ray diffraction. The octa-hedral iron coordination polyhedron contains two di(pyrimidin-2-yl)amine ligands coordinated in a bidentate fashion, and two monodentate dicyanimido ligands, each coordinated via a terminal N atom, with the latter in a cis orientation. The ligand configuration about the iron atom is chiral, although the compound crystallizes as a racemic mixture: the Fe-N distances (> 2.07 Å) are characteristic of high-spin iron(II). In the crystal, an extensive series of N-H⋯N, O-H⋯N and O-H⋯O hydrogen bonds links the independent mol-ecular components into a three-dimensional framework. The H atoms of both water mol-ecules are disordered. The structure also features some π-π and anion-π inter-actions. The inter-molecular inter-actions were investigated by Hirshfeld surface analysis and two-dimensional fingerprint plots. Comparisons are made with some related compounds.

Synthesis of 5-(arylmethylideneamino)-4-(1H-benzo[d]imidazol-1-yl)pyrimidine hybrids: synthetic sequence and the molecular and supramolecular structures of two intermediates and three final products.

A concise and versatile synthesis of 5-(arylmethylideneamino)-4-(1H-benzo[d]imidazol-1-yl)pyrimidines has been developed, starting from 4-(1H-benzo[d]imidazol-1-yl)pyrimidines, and we report here the synthesis and spectroscopic and structural characterization of three such products, along with those of two intermediates in the reaction pathway. The intermediates 4-[2-(4-chlorophenyl)-1H-benzo[d]imidazol-1-yl]-6-methoxypyrimidine-2,5-diamine, (II), and 4-[2-(4-bromophenyl)-1H-benzo[d]imidazol-1-yl]-6-methoxypyrimidine-2,5-diamine, (III), crystallize as the isostructural monohydrates C18H15ClN5O·H2O and C18H15BrN5O·H2O, respectively, in which the components are linked into complex sheets by O-H...N and N-H...O hydrogen bonds. In the product (E)-4-methoxy-5-[(4-nitrobenzylidene)amino]-6-[2-(4-nitrophenyl)-1H-benzo[d]imidazol-1-yl]pyrimidin-2-amine, which crystallizes as a 1:1 solvate with dimethyl sulfoxide, C25H18N8O5·C2H6OS, (IV), inversion-related pairs of the pyrimidine component are linked by N-H...N hydrogen bonds to form cyclic centrosymmetric R22(8) dimers to which pairs of solvent molecules are linked by N-H...O hydrogen bonds. (E)-4-Methoxy-5-[(4-methylbenzylidene)amino]-6-[2-(4-methylphenyl)-1H-benzo[d]imidazol-1-yl]pyrimidin-2-amine, C27H24N6O, (V), crystallizes with Z' = 2 and the molecules are linked into a three-dimensional framework structure by a combination of N-H...N, C-H...N and C-H...π(arene) hydrogen bonds. The analogous product (E)-4-methoxy-5-[(4-chlorobenzylidene)amino]-6-[2-(4-methylphenyl)-1H-benzo[d]imidazol-1-yl]pyrimidin-2-amine, C26H21ClN6O, (VI), crystallizes from dimethyl sulfoxide in two forms: one, denoted (VIa), is isostructural with (V), and the other, denoted (VIb), crystallizes with Z' = 1, but as an unknown solvate in which the pyrimidine molecules are linked by N-H...N hydrogen bonds to form a ribbon containing two types of centrosymmetric ring.

(E,E)-1,1'-[1,2-Bis(4-chlorophenyl)ethane-1,2-diyl]bis(phenyldiazene) revisited: threefold configurational disorder of (S,S), (R,R) and (S,R) isomers, a detailed critique.

Crystal structures described as concomitant triclinic (I) and monoclinic (II) polymorphs of meso-(E,E)-1,1'-[1,2-bis(4-chlorophenyl)ethane-1,2-diyl]bis(phenyldiazene) [Mohamed et al. (2016). Acta Cryst. C72, 57-62] have been re-investigated. The published model for II was distorted due to forcing the symmetry of space group C2/c on an incomplete structure model. It is shown here to be a likely three-component superposition of S,S and R,R enantiomers with a lesser amount of the meso form. A detailed analysis of how the improbable distortion in the published model aroused suspicion and the subsequent construction of undistorted chemically and crystallographically plausible alternatives having the symmetry of Cc and C2/c is presented. For the sake of completeness, an improved model for the triclinic P-1 structure of the meso isomer I, revised to include a minor disorder component, is also given.

Conversion of 2-methyl-4-styrylquinolines into 2,4-distyrylquinolines: synthesis, and spectroscopic and structural characterization of five examples.

Four new 2,4-distyrylquinolines and one 2-styryl-4-[2-(thiophen-2-yl)vinyl]quinoline have been synthesized using indium trichloride condensation reactions between aromatic aldehydes and the corresponding 2-methylquinolines, which were themselves prepared using Friedländer annulation reactions between mono- or diketones and (2-aminophenyl)chalcones: the products have all been fully characterized by spectroscopic and crystallographic methods. 2,4-Bis[(E)-styryl]quinoline, C25H19N, (IIa), and its dichloro analogue, 2-[(E)-2,4-dichlorostyryl]-4-[(E)-styryl]quinoline, C25H17Cl2N, (IIb), exhibit different orientations of the 2-styryl unit relative to the quinoline nucleus. In each of the 3-benzoyl analogues {2-[(E)-4-bromostyryl]-4-[(E)-styryl]quinolin-3-yl}(phenyl)methanone, C32H22BrNO, (IIc), {2-[(E)-4-bromostyryl]-4-[(E)-4-chlorostyryl]quinolin-3-yl}(phenyl)methanone, C32H21BrClNO, (IId), and {2-[(E)-4-bromostyryl]-4-[(E)-2-(thiophen-2-yl)vinyl]quinolin-3-yl}(phenyl)methanone, C30H20BrNOS, (IIe), the orientation of the 2-styryl unit is similar to that in (IIa), but the orientation of the 4-arylvinyl units show considerable variation. The thiophene unit in (IIe) is disordered over two sets of atomic sites having occupancies of 0.926 (3) and 0.074 (3). There are no hydrogen bonds of any kind in the structure of (IIa), but in (IId), a single C-H...O hydrogen bond links the molecules into cyclic centrosymmetric R22(20) dimers. A combination of C-H...N and C-H...π hydrogen bonds links the molecules of (IIb) into a three-dimensional framework structure. A combination of three C-H...π hydrogen bonds links the molecules of (IIc) into sheets, and a combination of C-H...O and C-H...π hydrogen bonds forms sheets in (IIe). Comparisons are made with the structures of some related compounds.

A three-step pathway from (2-aminophenyl)chalcones to novel styrylquinoline-chalcone hybrids: synthesis and spectroscopic and structural characterization of three examples.

Three new styrylquinoline-chalcone hybrids have been synthesized using a three-step pathway starting with Friedländer cyclocondensation between (2-aminophenyl)chalcones and acetone to give 2-methyl-4-styrylquinolines, followed by selective oxidation to the 2-formyl analogues, and finally Claisen-Schmidt condensation between the formyl intermediates and 1-acetylnaphthalene. All intermediates and the final products have been fully characterized by IR and 1H/13C NMR spectroscopy, and by high-resolution mass spectrometry, and the three products have been characterized by single-crystal X-ray diffraction. The molecular conformations of (E)-3-{4-[(E)-2-phenylethenyl]quinolin-2-yl}-1-(naphthalen-1-yl)prop-2-en-1-one, C30H21NO, (IVa), and (E)-3-{4-[(E)-2-(4-fluorophenyl)ethenyl]quinolin-2-yl}-1-(naphthalen-1-yl)prop-2-en-1-one, C30H20FNO, (IVb), are very similar. In each compound, the molecules are linked into a three-dimensional array by hydrogen bonds, of the C-H...O and C-H...N types in (IVa), and of the C-H...O and C-H...π types in (IVb), and by two independent π-π stacking interactions. By contrast, the conformation of the chalcone unit in (E)-3-{4-[(E)-2-(2-chlorophenyl)ethenyl]quinolin-2-yl}-1-(naphthalen-1-yl)prop-2-en-1-one, C30H20ClNO, (IVc), differs from those in (IVa) and (IVb). There are only weak hydrogen bonds in the structure of (IVc), but a single rather weak π-π stacking interaction links the molecules into chains. Comparisons are made with some related structures.

Synthesis, and spectroscopic and structural characterization of three new styrylquinoline-benzimidazole hybrids.

Three new 4-styrylquinoline-benzimidazole hybrids have been synthesized using a reaction sequence in which 2-methylquinoline precursors first undergo selective oxidation by selenium dioxide to form the corresponding 2-formylquinoline intermediates, followed by oxidative cyclocondensation reactions with benzene-1,2-diamine to yield the hybrid products. The formyl intermediates and the hybrid products have all been fully characterized using a combination of IR, 1H and 13C NMR spectroscopy, and high-resolution mass spectrometry, and the structures of the three hybrid products have been determined using single-crystal X-ray diffraction. Ethyl (E)-2-(1H-benzo[d]imidazol-2-yl)-4-(4-chlorostyryl)quinoline-3-carboxylate, C27H20ClN3O2, (IIIa), and ethyl (E)-2-(1H-benzo[d]imidazol-2-yl)-4-(2-methoxystyryl)quinoline-3-carboxylate, C28H23N3O3, (IIIb), both crystallize in the solvent-free form with Z' = 1, but ethyl (E)-2-(1H-benzo[d]imidazol-2-yl)-4-(4-methylstyryl)quinoline-3-carboxylate, C28H23N3O2, (IIIc), crystallizes as a partial hexane solvate with Z' = 3, and the ester group in one of the independent molecules is disordered over two sets of atomic sites having occupancies of 0.765 (7) and 0.235 (7). The molecules of (IIIc) enclose continuous channels which are occupied by disordered solvent molecules having partial occupancy. In all of the molecules of (IIIa)-(IIIc), the styrylquinoline fragment is markedly nonplanar. Different combinations of N-H...O and C-H...π hydrogen bonds generate supramolecular assemblies which are two-dimensional in (IIIb) and (IIIc), but three-dimensional in (IIIa). Comparisons are made with the structures of some related compounds.

Synthesis and crystal structure of topiramate azido-sulfate at 90†K and 298†K.

The low (90 K) and room (298 K) temperature crystal structures of topiramate azido-sulfate [systematic name 2,3:4,5-bis-O-(1-methyl-ethyl-idene)-ß-d-fructo-pyran-ose azido-sulfate], C12H19N3O8S, an inter-mediate in the synthesis of the anti-convulsant drug topiramate, are described. Topiramate azido-sulfate (I) finds use as a reference impurity standard for topiramate. A modified synthesis and some spectroscopic details are also presented.

Synthesis and spectroscopic and structural characterization of three new 2-methyl-4-styrylquinolines formed using Friedländer reactions between (2-aminophenyl)chalcones and acetone.

Three new 2-methyl-4-styrylquinoline derivatives have been synthesized in high yields using Friedländer reactions between chalcones [1-(2-aminophenyl)-3-arylprop-2-en-1-ones] and acetone, and characterized using IR, 1H and 13C NMR spectroscopy, and mass spectrometry, and by crystal structure analysis. In (E)-4-(4-fluorostyryl)-2-methylquinoline, C18H14FN, (I), the molecules are joined into cyclic centrosymmetric dimers by C-H...N hydrogen bonds and these dimers are linked into sheets by π-π stacking interactions. The molecules of (E)-2-methyl-4-[4-(trifluoromethyl)styryl]quinoline, C19H14F3N, (II), are linked into cyclic centrosymmetric dimers by C-H...π hydrogen bonds and these dimers are linked into chains by a single π-π stacking interaction. There are no significant hydrogen bonds in the structure of (E)-4-(2,6-dichlorostyryl)-2-methylquinoline, C18H13Cl2N, (III), but molecules related by translation along [010] form stacks with an intermolecular spacing of only 3.8628 (2) Å. Comparisons are made with the structures of some related compounds.

Syntheses and crystal structures of 4-(4-meth-oxy-phen-yl)piperazin-1-ium 4-methyl-benzoate monohydrate and bis-[4-(4-meth-oxy-phen-yl)piperazin-1-ium] benzene-1,2-di-carboxyl-ate.

Co-crystallization of N-(4-meth-oxy-phen-yl)piperazine with 4-methyl-benzoic acid and with benzene-1,2-di-carb-oxy-lic acid yields the salts 4-(4-meth-oxy-phen-yl)piperazin-1-ium 4-methyl-benzoate monohydrate, C11H17N2O+·C8H7O2 -·H2O (I), and bis-[4-(4-meth-oxy-phen-yl)piperazin-1-ium] benzene-1,2-di-carboxyl-ate, 2C11H17N2O+·C8H4O4 2- (II). These salts both crystallize with Z' = 2, in space groups P and Pna21, respectively. In compound (I), a combination of four O-H⋯O, four N-H⋯O, one C-H⋯O and one C-H⋯π(arene) hydrogen bonds link the six independent components into complex sheets, within which the two piperazine rings, the two anions, and the two water mol-ecules are related by an approximate, non-crystallographic translation along the b-axis direction. In compound (II), sheets containing R 4 4(18) and R 10 12(38) rings are formed by the combined action of eight independent N-H⋯O hydrogen bonds. Comparisons are made with the structures of some related compounds.

Syntheses and crystal structures of 4-(4-nitro-phen-yl)piperazin-1-ium benzoate monohydrate and 4-(4-nitro-phen-yl)piperazin-1-ium 2-carb-oxy-4,6-di-nitro-phenolate.

Crystal structures are reported for two mol-ecular salts containing the 4-(4-nitro-phen-yl)piperazin-1-ium cation. Co-crystallization from methanol/ethyl acetate solution of N-(4-nitro-phen-yl)piperazine with benzoic acid gives the benzoate salt, which crystallizes as a monohydrate, C10H14N3O2·C7H5O2·H2O, (I), and similar co-crystallization with 3,5-di-nitro-salicylic acid yields the 2-carb-oxy-4,6-di-nitro-phenolate salt, C10H14N3O2·C7H3N2O7, (II). In the structure of (I), a combination of O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds links the components into sheets, while in the structure of (II), the supra-molecular assembly, generated by hydrogen bonds of the same types as in (I), is three dimensional. Comparisons are made with the structures of some related compounds.

Formation of 1-(thia-zol-2-yl)-4,5-di-hydropyrazoles from simple precursors: synthesis, spectroscopic characterization and the structures of an inter-mediate and two products.

Two new 1-(thia-zol-2-yl)-4,5-di-hydropyrazoles have been synthesized from simple precursors, and characterized both spectroscopically and structurally. In addition, two inter-mediates in the reaction pathway have been isolated and characterized, one of them structurally. The mol-ecules of the inter-mediate (E)-1-(4-meth-oxy-phen-yl)-3-[4-(prop-2-yn-yloxy)phen-yl]prop-2-en-1-one, C19H16O3 (I), are linked by a combination of C-H⋯O and C-H⋯π(arene) hydrogen bonds to form ribbons. The products (RS)-5-(4-meth-oxy-phen-yl)-1-(4-phenythiazol-2-yl)-3-[4-(prop-2-yn--yloxy)phen-yl]-4,5-di-hydro-1H-pyrazole, C28H23N3O2S (II), and (RS)-5-(4-meth-oxy-phen-yl)-1-[4-(4-methyl-phen-yl)thia-zol-2-yl]-3-[4-(prop-2-yn-yloxy)phen-yl]-4,5-di-hydro-1H-pyrazole, C29H25N3O2S (III), are closely related - differing only by presence or absence of a methyl group at the aryl-thia-zolyl substituent - and crystallize in an isomorphous setting. Both mol-ecules contain an effectively planar di-hydro-pyrazole ring, and possess an overall T-shaped structure, which is a characteristic of triaryl-substituted 4,5-di-hydro-1-(thia-zol-2-yl)pyrazole compounds. The crystal packing is characterized by inter-molecular C-H⋯S and C-H⋯π (ar-yl/alkyne) inter-actions. A combination of two C-H⋯π(arene) hydrogen bonds links the product mol-ecules into sheets.

Synthesis and spectroscopic and structural characterization of spiro[indoline-3,3'-indolizine]s formed by 1,3-dipolar cycloadditions between isatins, pipecolic acid and an electron-deficient alkene.

Five new spiro[indoline-3,3'-indolizine]s have been synthesized with high regio- and stereospecificity in one-pot three-component reactions between a substituted indole-2,3-dione, (S)-pipecolic acid and trans-3-benzoylacrylic acid, and subsequently characterized using a combination of elemental analysis, IR and 1H and 13C NMR spectroscopy, mass spectrometry and crystal structure analysis. (1'SR,2'SR,3RS,8a'RS)-2'-Benzoyl-5-fluoro-2-oxo-1',5',6',7',8',8a'-hexahydro-2'H-spiro[indoline-3,3'-indolizine]-1'-carboxylic acid, C23H21FN2O4, (I), and (1'SR,2'SR,3RS,8a'RS)-2'-benzoyl-5-methyl-2-oxo-1',5',6',7',8',8a'-hexahydro-2'H-spiro[indoline-3,3'-indolizine]-1'-carboxylic acid, C24H24N2O4, (II), are isomorphous, as are (1'SR,2'SR,3RS,8a'RS)-2'-benzoyl-1-methyl-2-oxo-1',5',6',7',8',8a'-hexahydro-2'H-spiro[indoline-3,3'-indolizine]-1'-carboxylic acid, C24H24N2O4, (III), and (1'SR,2'SR,3RS,8a'RS)-2'-benzoyl-5-chloro-1-methyl-2-oxo-1',5',6',7',8',8a'-hexahydro-2'H-spiro[indoline-3,3'-indolizine]-1'-carboxylic acid, C24H23ClN2O4, (IV). Within each isomorphous pair, the spiro ring systems show some conformational differences. In each of (I) and (II), the molecules are linked into complex sheets by a combination of four types of hydrogen bond, and in each of (III) and (IV), a combination of O-H...O and C-H...π(arene) hydrogen bonds links the molecules to form a chain of centrosymmetric rings. In (1'SR,2'SR,3RS,8a'RS)-2'-benzoyl-1-hexyl-2-oxo-1',5',6',7',8',8a'-hexahydro-2'H-spiro[indoline-3,3'-indolizine]-1'-carboxylic acid, C29H34N2O4, (V), a combination of five hydrogen bonds links the molecules into sheets of alternating R22(16) and R66(46) rings. A mechanism is proposed for the formation of compounds (I)-(V) and some comparisons with related structures are made.

Reduced 3,4'-bi-pyrazoles carrying thio-phene and thia-zole substituents: structures of two intermediates and two products.

Cyclo-addition reactions between 3-(5-ar-yloxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)-1-(thio-phen-2-yl)prop-2-en-1-ones and thio-semicarbazide leads to the formation of reduced 3,4'-bi-pyrazole-2-carbo-thio-amides. Further cyclo-addition of these inter-mediates with either diethyl acetyl-enedi-carboxyl-ate or 4-bromo-phenacyl bromide leads to reduced 3,4'-bi-pyrazoles carrying oxo-thia-zole or thia-zole substituents, respectively. The structures of two representative inter-mediates and two representative products established unambiguously the regiochemistry of the cyclo-addition reactions. The mol-ecules of 3'-methyl-5'-(2-methyl-phen-oxy)-1'-phenyl-5-(thio-phen-2-yl)-3,4-di-hydro-1'H,2H-3,4'-bi-pyra-zole-2-carbo-thio-amide, C25H23N5OS2 (Ia), are linked by N-H⋯N hydrogen bonds to form simple C(8) chains. The analogous compound 5'-(2,4-di-chloro-phen-oxy)-3'-methyl-1'-phenyl-5-(thio-phen-2-yl)-3,4-di-hydro-1'H,2H-3,4'-bi-pyra-zole-2-carbo-thio-amide hemihydrate crystallizes as a hemihydrate, C24H19Cl2N5OS2·0.5H2O (Ib), and the independent components are linked into a chain of spiro-fused R 4 4(20) rings by a combination of O-H⋯N and N-H⋯O hydrogen bonds. In the structure of ethyl (Z)-2-{2-[3'-methyl-1'-phenyl-5-(thio-phen-2-yl)-5'-(2-methyl-phen-oxy)-3,4-di-hydro-1'H,2H-3,4'-bi-pyrazole-2-yl]-4-oxo-4,5-di-hydro-thia-zol-5-yl-idene}acetate, C31H27N5O4S2 (II), inversion-related pairs of mol-ecules are linked by paired C-H⋯π(arene) hydrogen bonds to form cyclic centrosymmetric dimers, but there are no direction-specific inter-molecular inter-actions in 4-(4-bromo-phen-yl)-2-[5'-(2,4-di-chloro-phen-oxy)-3'-methyl-1'-phenyl-5-(thio-phen-2-yl)-3,4-di-hydro-1'H,2H-3,4'-bi-pyrazole-2-yl]-4-thia-zole, C32H22BrCl2N5OS2 (III). Comparisons are made with the structures of some related compounds.

The crystal structures of three disordered 2-substituted benzimidazole esters.

The crystal structures of three benzimidazole esters containing aryl or heterocyclic substituents at position 2 are reported, and all three exhibit disorder of mol-ecular entities. In ethyl 1-methyl-2-[4-(prop-2-yn-oxy)phen-yl]-1H-benzimidazole-5-carboxyl-ate, C20H18N2O3, (I), the prop-2-yn-1-oxyphenyl unit is disordered over two sets of atomic sites having effectively equal occupancies, 0.506 (5) and 0.494 (5). The propyl substituent in ethyl 1-propyl-2-(pyren-1-yl)-1H-benzimidazole-5-carboxyl-ate, C29H24N2O2, (II), is disordered over two sets of atomic sites having occupancies 0.601 (8) and 0.399 (8), and the ester unit in ethyl 1-methyl-2-(5-chloro-3-methyl-1-phenyl-1H-pyrazol-4-yl)-1H-benzimidazole-5-carboxyl-ate, C21H19ClN4O2 (III), is disordered over two sets of atomic sites having occupancies 0.645 (7) and 0.355 (7). In each of the C-H⋯π(arene) hydrogen bonds in (I), the donor and acceptor form parts of different disorder components, so that no continuous aggregation is possible. The mol-ecules of (II) are linked by a single C-H⋯O hydrogen bond into C(10) chains, which are linked into sheets by a π-π stacking inter-action, whereas those of (III) are just linked into C(13) chains, again by a single C-H⋯O hydrogen bond. Comparisons are made with the structures of some related compounds.

Different patterns of supra-molecular aggregation in three amides containing N-(benzo[d]thia-zol-yl) substituents.

Crystal structures are reported for three amides containing N-benzo[d]thia-zole substituents. In N-(benzo[d]thia-zol-6-yl)-3-bromo-benzamide, C14H9BrN2OS, where the two ring systems are nearly parallel to one another [dihedral angle = 5.8 (2)°], the mol-ecules are linked by N-H⋯O and C-H⋯N hydrogen bonds to form ribbons of R 3 3(19) rings, which are linked into sheets by short Br⋯Br inter-actions [3.5812 (6) Å]. N-(6-Meth-oxy-benzo[d]thia-zol-2-yl)-2-nitro-benzamide, C15H11N3O4S, crystallizes with Z' = 2 in space group Pna21: the dihedral angles between the ring systems [46.43 (15) and 66.35 (13)°] are significantly different in the independent mol-ecules and a combination of two N-H⋯N and five C-H⋯O hydrogen bonds links the mol-ecules into a three-dimensional network. The mol-ecules of 5-cyclo-propyl-N-(6-meth-oxy-ben-zo[d]thia-zol-2-yl)-isoxazole-3-carboxamide, C15H13N3O3S, exhibit two forms of disorder, in the meth-oxy group and in the cyclo-propyl-isoxazole unit; symmetry-related pairs of mol-ecules are linked into dimers by pairwise N-H⋯N hydrogen bonds. Comparisons are made with the structures of some related compounds.

Six 1-halobenzoyl-4-(2-meth-oxy-phen-yl)piperazines having Z' values of one, two or four; disorder, pseudosymmetry, twinning and supra-molecular assembly in one, two or three dimensions.

Six 1-halobenzoyl-4-(2-meth-oxy-phen-yl)piperazines have been prepared using carbodi-imide-mediated coupling reactions between halo-benzoic acids and N-(2-meth-oxy-phen-yl)piperazine. The mol-ecules of 1-(4-fluoro-benzo-yl)-4-(2-meth-oxy-phen-yl)piperazine, C18H19FN2O2 (I), are linked into a chain of rings by a combination of C-H⋯O and C-H⋯π(arene) hydrogen bonds. 1-(4-Chloro-benzo-yl)-4-(2-meth-oxy-phen-yl)piperazine, C18H19ClN2O2 (II), crystallizes in the space group Pca21 with Z' = 4 and it exhibits both pseudosymmetry and inversion twinning: a combination of six C-H⋯O and two C-H⋯π(arene) hydrogen bonds generate a three-dimensional assembly. In 1-(4-bromo-benzo-yl)-4-(2-meth-oxy-phen-yl)piperazine, C18H19BrN2O2 (III), which also crystallizes in space group Pca21 but with Z' = 2, the bromo-benzoyl unit in one of the mol-ecules is disordered. Pseudosymmetry and inversion twinning are again present, and a combination of three C-H⋯O and one C-H⋯π(arene) hydrogen bonds generate a two-dimensional assembly. A single C-H⋯O hydrogen bond links the mol-ecules of 1-(4-iodo-benzo-yl)-4-(2-meth-oxy-phen-yl)piperazine, C18H19IN2O2 (IV), into simple chains but in the isomeric 3-iodo-benzoyl analogue (V), which crystallizes in space group P212121 with Z' = 2, a two-dimensional assembly is generated by a combination of four C-H⋯O and two C-H⋯π(arene) hydrogen bonds; pseudosymmetry and inversion twinning are again present. A single C-H⋯O hydrogen bond links the mol-ecules of 1-(2-fluoro-benzo-yl)-4-(2-meth-oxy-phen-yl)piperazine, C18H19FN2O2 (VI), into simple chains. Comparisons are made with the structures of some related compounds.

Two 3-amino-1H-pyrazol-2-ium salts containing organic anions, and an ortho-rhom-bic polymorph of 3-amino-1H-pyrazol-2-ium nitrate.

Co-crystallization from methanol of 3-amino-1H-pyrazole with 3,5-di-nitro-benzoic acid produces 3-amino-1H-pyrazol-2-ium 3,5-di-nitro-benzoate monohydrate, C3H6N3 +·C7H3N2O6 -·H2O, (I), while similar co-crystallization of this pyrazole with an equimolar qu-antity of fumaric acid produces bis-(3-amino-1H-pyrazol-2-ium) fumarate-fumaric acid (1/1), 2C3H6N3 +·C4H2O4 2-·C4H4O4, (II). The reaction of 3-amino-1H-pyrazole with a dilute solution of nitric acid in methanol yields a second, ortho-rhom-bic polymorph of 3-amino-1H-pyrazol-2-ium nitrate, C3H6N3 +·NO3 -, (III). In each of (I)-(III), the bond distances in the cation provide evidence for extensive delocalization of the positive charge. In each of (I) and (II), an extensive series of O-H⋯O and N-H⋯O hydrogen bonds links the components into complex sheets, while in the structure of (III), the ions are linked by multiple N-H⋯O hydrogen bonds into a three-dimensional arrangement. Comparisons are made with the structures of some related compounds.

catena-Poly[[bis-(quinolin-8-amine-κ2 N,N')cadmium(II)]-µ-cyanido-κ2 N:C-[dicyanidonickel(II)]-µ-cyanido-κ2 C:N].

In the title compound, [CdNi(C9H8N2)2(CN)4] n , the Cd and Ni atoms both lie on centres of inversion in space group P21/c. The Cd atom is coordinated by two bidentate quinolin-8-amine ligands and by the N atoms of two cyano ligands, while the square planar Ni atom is coordinated by the C atoms of four cyano ligands. These units form a one-dimensional coordination polymer containing an (-NC-Ni-CN-Cd-) n backbone, and the coordination polymer chains are linked into a three-dimensional array by a combination of N-H⋯N and C-H⋯N hydrogen bonds, augmented by a π-π stacking inter-action.

Fifteen 4-(2-meth-oxy-phen-yl)piperazin-1-ium salts containing organic anions: supra-molecular assembly in zero, one, two and three dimensions.

Fifteen 4-(2-meth-oxy-phen-yl)piperazin-1-ium salts containing organic anions have been prepared and structurally characterized. In the isostructural 4-chloro-benzoate and 4-bromo-benzoate salts, C11H17N2O+·C7H4ClO2 - (I) and C11H17N2O+·C7H4BrO2 - (II), and the 4-iodo-benzoate salt C11H17N2O+·C7H4IO2 - (III), the ions are linked by N-H⋯O hydrogen bonds, forming centrosymmetric R 4 4(12) four-ion aggregates; a similar aggregate is formed in the 2-chloro-benzoate salt (V), isomeric with (I). In the 2-fluoro-benzoate salt C11H17N2O+·C7H4FO2 - (IV), and the isomorphous pair of salts, the 2-bromo-benzoate (VI), isomeric with (II) and 2-iodo-benzoate (VII), isomeric with (III), N-H⋯O and C-H⋯π(arene) interactions link the components into three-dimensional arrays. Four-ion R 4 4(12) aggregates are also found in the 2-methyl-benzoate, 4-amino-benzoate and 4-nitro-benzoate salts, C11H17N2O+·C8H7O2 - (VIII), C11H17N2O+·C7H6NO2 - (IX) and C11H17N2O+·C7H4NO4 - (X), but those in (IX) are linked into complex sheets by an additional N-H⋯O hydrogen bond. In the 3,5-dinitrobenzoate salt, C11H17N2O+·C7H3N2O6 -·2H2O (XI), N-H⋯O and O-H⋯O hydrogen bonds link the components into a complex ribbon structure. In the picrate salt, C11H17N2O+·C6H2N3O7 - (XII), the four-ion aggregates are linked into chains of rings by C-H⋯O hydrogen bonds. In the hydrogen maleate salt, C11H17N2O+·C4H3O4 - (XIII), two- and three-centre hydrogen bonds link the ions into a ribbon structure while both anions contain very short but asymmetric O-H⋯O hydrogen bonds, having O⋯O distances of 2.4447 (16) and 2.4707 (17) Å. O-H⋯O Hydrogen bonds link the anions in the hydrogen fumarate salt (XIV), isomeric with (XIII), into chains that are linked into sheets via N-H⋯O hydrogen bonds. In the hydrogen (2R,3R)-tartrate salt, C11H17N2O+·C4H5O6 -·1.698H2O (XV), the anions are linked into sheets by O-H⋯O hydrogen bonds. Comparisons are made with the structures of some related compounds.

Order versus disorder in two isomorphous pyrazolone-substituted diethyl propane-dioates prepared using a three-component one-pot reaction under solvent-free conditions.

Two new substituted propane-dioate esters have been synthesized using a three-component solvent-free thermal reaction between diethyl propane-dioate (diethyl malonate), 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde and an aryl azide, forming two new C-C bonds in a single step. The products diethyl (RS)-2-[(4-bromo-phen-yl)(5-methyl-3-oxo-2-phenyl-2,3-di-hydro-1H-pyrazol-4-yl)meth-yl]propane-dioate, C24H25BrN2O5 (I), and diethyl (RS)-2-[(4-chloro-phen-yl)(5-methyl-3-oxo-2-phenyl-2,3-di-hydro-1H-pyrazol-4-yl)meth-yl]propane-dioate, C24H25ClN2O5 (II), are isomorphous, with Z' = 2 in space group P21/n. The two independent mol-ecules in compound (I) are both fully ordered, while each of the independent mol-ecules in compound (II) is disordered, but in different ways. In one mol-ecule of (II), the N-phenyl ring is disordered over two sets of atomic sites having occupancies 0.635 (10) and 0.365 (10), and in the other mol-ecule the ester function is disordered over two sets of atomic sites having occupancies 0.690 (5) and 0.310 (5). In both structures, the two independent mol-ecules adopt different conformations and, in each structure, the mol-ecules are linked into complex sheets by a combination of N-H⋯O, C-H⋯O and C-H⋯π(arene) hydrogen bonds. Comparisons are made with some related structures.