A NEW RARE HALOGENATED DEPSIDE FROM LICHEN AND STUDY OF ITS ANTI-PROLIFERATIVE ACTIVITY.

Lichens are (Permotrema parlatum) a symbiotic association of algae and fungus belonging to the family Parmeliaceae. Some of lichen species are consumable and used as an active ingredient for preparation exotic spices as well as folklore medicine to cure different kind of ailments. A specimen of lichen was collected from Munner in Kerala State of South India for its chemical profiling. Chemical analyses of diethyl extract of the defatted lichen led to the isolation of six phenols 1-6 with variation of relative abundance. Amongst them, the relative abundance of compound 3 was maximum (1% of crude extract) and it was identified as atranorin. The structures of known compounds were identified in comparison with their 1H & 13C NMR and mass data with published values available in literature. In vitro, bioassay of anti-proliferative activity of these compounds has been conducted against various human cancer cell lines in comparison with paclitaxel as control using SRB assay.

Syntheses and crystal structures of three salts of 1-(4-nitro-phenyl)-piperazine.

The crystal structures and Hirshfeld surface analyses of three salts of 1-(4-nitro-phenyl)-piperazine with 2-chloro-benzoic acid, 2-bromo-benzoic acid and 2-iodo-benzoic acid are reported. The chloro-benzoate salt, C10H14N3O2 +·C7H4ClO2 -, contains whole-ion-disordered cations and anions, which were modeled with two equivalent conformations with occupancies of 0.745 (10)/0.255 (10) and 0.563 (13)/0.437 (13), respectively. The bromo-benzoate and iodo-benzoate derivatives are isomorphous and crystallize as hemihydrates, viz. C10H14N3O2 +·C7H4BrO2 -·0.5H2O and C10H14N3O2 +·C7H4IO2 -·0.5H2O, respectively [the water mol-ecule is disordered over two locations with occupancies of 0.276 (3)/0.223 (3) for the iodo-benzoate derivative]. In the extended structures, all three salts feature an R 4 4(12) loop of two anions and two cations linked by N-H⋯O hydrogen bonds.

Syntheses, crystal structures and Hirshfeld surface analysis of three salts of 1-(4-nitro-phenyl)-piperazine.

The structures and Hirshfeld surface analysis of three salts of 1-(4-nitro-phenyl)-piperazine are discussed. In 4-(4-nitro-phen-yl)piperazin-1-ium salicylate (C10H14N3O2 +·C7H5O3 -), there are strong hydrogen bonds between cation and anion and the 4-nitro-phenyl substituent occupies an equatorial position in the piperazinium ring. The cation and anion are linked together by supra-molecular inter-actions [graph-set notation of hydrogen bonding (6) propagating in the a-axis direction]. Additionally, there is π-π stacking involving the salicylate anion and the piperazinium cation in adjacent asymmetric units as well as a C-H⋯π inter-action between a hydrogen atom on the piperazine ring and the phenyl ring within the salicyclate anion. In bis-[4-(4-nitro-phen-yl)piperazin-1-ium] bis-(4-fluoro-benzoate) trihydrate (2C10H14N3O2 +·2C7H4FO2 -·3H2O), there are two cations, two anions, and three water mol-ecules of solvation in the asymmetric unit, all linked by hydrogen bonds [graph-set notation of hydrogen bonding R 2 2(20) between adjacent cations and R 3 3(9) between a cation and its adjacent anion]. In the anion, the 4-nitro-phenyl ring occupies an axial substitution position in the piperazinium ring, which is relatively rare. Within the asymmetric unit, the phenyl groups in the cations show an offset π-π inter-action. Additionally, there is a C-H⋯π inter-action between a hydrogen atom on the phenyl ring within a cation and the phenyl ring within an anion. In 4-(4-nitro-phen-yl)piperazin-1-ium 3,5-di-nitro-benzoate (C10H14N3O2 +·C7H4N2O6 -), there is a strong N-H⋯O hydrogen bond linking the cation and anion and the 4-nitro-phenyl ring occupies an axial substitution position in the piperazinium ring, as seen in the previous structure. In the crystal, the cation and the anion form a complex three-dimensional hydrogen-bonded array involving R 2 2(8), R 4 4(12) and R 4 4(20) rings propogating in the a-axis direction. The nitro-phenyl group is disordered with occupancies of 0.806 (10) and 0.194 (10).

Syntheses, crystal structures and Hirshfeld surface analysis of 4-(4-nitro-phen-yl)piperazin-1-ium tri-fluoro-acetate and 4-(4-nitro-phen-yl)piperazin-1-ium tri-chloro-acetate.

The synthesis and crystal structures of the mol-ecular salts of 4-(4-nitro-phen-yl)piperazine with tri-fluoro-acetate, namely, 4-(4-nitro-phen-yl)piperazin-1-ium tri-fluoro-acetate, C10H14N3O2 +·C2F3O2 - (I), and with tri-chloro-acetate, namely, 4-(4-nitro-phen-yl)piperazin-1-ium tri-chloro-acetate, C10H14N3O2 +·C2Cl3O2 -, (II), are reported and compared. A partial positional disorder of the anions was found. In both structures, the piperazine rings adopt a chair conformation, whereas the positions of the nitro-phenyl group on the piperazine ring differ from bis-ectional in (I) to equatorial in (II). In both structures, the supra-molecular assemblies are mono-periodic on the basis of the chain-of-rings motifs supported by aromatic π-π inter-actions. Hirshfeld surface analysis was used to explore the inter-molecular close contacts in both crystals. The most dominant contacts of the Hirshfeld surface of the cation-anion pairs of the asymmetric units are O⋯H/H⋯O, and those with a contribution of halogen atoms: F⋯H/H⋯F in (I) and Cl⋯H/H⋯Cl in (II), respectively.

Isopropyl 4-amino-benzoate.

The title compound, C10H13NO2, crystallizes with two mol-ecules (A and B) in the asymmetric unit. For A, the dihedral angle between the plane of the phenyl ring and the i-propyl substituent is 65.4 (3)° while for B this angle is 67.8 (3)°. In the crystal, the mol-ecules are linked by N-H⋯O and N-H⋯N hydrogen bonds to generate double chains propagating in the [100] direction.

Anti-Proliferative Acyl Phenols and Arylnonanoids from the Fruit Rind of Myristica malabarica Lam.

Phytochemical investigation of the methanol extract of the fruit rind of Myristica malabarica led to the isolation of eight known compounds that were identified as malabaricones A-D, promalabaricones B and C, 1-(2,6-dihydroxyphenyl)tetradecan-1-one, and ericanone by comparison with literature spectroscopic data. The structures of malabaricones A-D, promalabaricone B, and 1-(2,6-dihydroxyphenyl)tetradecan-1-one were confirmed by X-ray crystallography. In vitro assay of the isolated phenols indicated that they exhibited moderate anti-proliferative activity against the A2780 human ovarian cancer cell. Compounds (1, 3, 5, 6 and 7) had the most potent activities, whereas the anti-proliferative activities of compounds 2 and 4 were less potent.

The structures of eleven (4-phen-yl)piperazinium salts containing organic anions.

Eleven (4-phen-yl)piperazinium salts containing organic anions have been prepared and structurally characterized, namely, 4-phenyl-piperazin-1-ium 4-fluoro-benzoate monohydrate, C10H15N2 +·C7H4FO2 -·H2O, 1; 4-phenyl-piperazin-1-ium 4-bromo-benzoate monohydrate, C10H15N2 +·C7H4BrO2 -·H2O, 3; 4-phenyl-piperazin-1-ium 4-iodo-benzoate, C10H15N2 +·C7H4IO2 -, 4; 4-phenyl-piperazin-1-ium 4-nitro-benzoate, C10H15N2 +·C7H4NO4 -, 5; 4-phenyl-piperazin-1-ium 3,5-di-nitro-salicylate, C10H15N2 +·C7H3N2O7 -, 6; 4-phenyl-piperazin-1-ium 3,5-di-nitro-benzoate, C10H15N2 +·C7H3N2O6 -, 7; 4-phenyl-piperazin-1-ium picrate, C10H15N2 +·C6H2N3O7 -, 8; 4-phenyl-piperazin-1-ium benzoate monohydrate, C10H15N2 +·C7H5O2 -·H2O, 9; 4-phenyl-piperazin-1-ium p-toluene-sulfonate, C10H15N2 +·C7H7O3S-, 10; 4-phenyl-piperazin-1-ium tartarate monohydrate, C10H15N2 +·C4H5O6 -·H2O, 11; and 4-phenyl-piperazin-1-ium fumarate, C10H15N2 +·C4H3O4 -, 12. Compounds 1 and 3-12 are all 1:1 salts with the acid proton transferred to the phenyl-piperaizine basic N atom (the secondary amine) with the exception of 3 where there is disorder in the proton position with it being 68% attached to the base and 32% attached to the acid. Of the structures with similar stoichiometries only 3 and 9 are isomorphous. The 4-phenyl substituent in all cases occupies an equatorial position except for 12 where it is in an axial position. The crystal chosen for structure 7 was refined as a non-merohedral twin. There is disorder in 5, 6, 10 and 11. For both 5 and 6, a nitro group is disordered and was modeled with two equivalent orientations with occupancies of 0.62 (3)/0.38 (3) and 0.690 (11)/0.310 (11), respectively. For 6, 10 and 11, this disorder is associated with the phenyl ring of the phenyl-piperazinium cation with occupancies of 0.687 (10)/0.313 (10), 0.51 (7)/0.49 (7) and 0.611 (13)/389 (13), respectively. For all salts, the packing is dominated by the N-H⋯O hydrogen bonds formed by the cation and anion. In addition, several structures contain C-H⋯π (1, 3, 4, 8, 9, 10, and 12) and aromatic π-π stacking inter-actions (6 and 8) and one structure (5) contains a -NO2⋯π inter-action. For all structures, the Hirshfeld surface fingerprint plots show the expected prominent spikes as a result of the N-H⋯O and O-H⋯O hydrogen bonds.

Crystal-structure studies of 4-phenyl-piperazin-1-ium 4-eth-oxy-benzoate monohydrate, 4-phenyl-piperazin-1-ium 4-meth-oxy-benzoate monohydrate, 4-phenyl-piperazin-1-ium 4-methyl-benzoate monohydrate and 4-phenyl-piperazin-1-ium tri-fluoro-acetate 0.12-hydrate.

In this study, four new piperazinium salts, namely, 4-phenyl-piperazin-1-ium 4-eth-oxy-benzoate monohydrate, C9H9O3·C10H15N2·H2O (I); 4-phenyl-piperazin-1-ium 4-meth-oxy-benzoate monohydrate, C10H15N2·C8H7O3·H2O (II); 4-phenyl-piperazin-1-ium 4-methyl-benzoate monohydrate, C10H15N2·C8H7O2·H2O (III); and 4-phenyl-piperazin-1-ium tri-fluoro-acetate 0.12 hydrate, C10H15N2·C2F3O2·0.12H2O (IV), have been synthesized. The single-crystal structures of these compounds reveal that all of them crystallize in the triclinic P space group and the crystal packing of (I)-(III) is built up of ribbons formed by a combination of hydrogen bonds of type N-H⋯O, O-H⋯O and other weak inter-actions of type C-H⋯O and C-H⋯π, leading to a three-dimensional network. In the crystal of (IV), the cations and the anions are connected by C-H⋯O, N-H⋯O and C-H⋯F hydrogen bonds and by C-H⋯π inter-actions, forming sheets which in turn inter-act to maintain the crystal structure by linking through the oxygen atoms of water mol-ecules and van der Waals inter-actions, giving the whole structure.

Synthesis, structural characterization, and evaluation of new peptidomimetic Schiff bases as potential antithrombotic agents.

New Schiff bases functionalized with amide and phenolic groups synthesized by the condensation of 2-hydroxybenzaldehyde and 2-hydroxyacetophenone with amino acid amides which in turn were prepared in two steps from N-Boc-amino acids and homoveraltrylamine through intermediate compounds N-Boc-amino acids amides. The compounds were characterized by elemental analysis, FT-IR, UV-Vis, and NMR spectroscopy. The crystal structures of three Schiff bases were determined by single crystal X-ray diffraction. There exists O-H ⋯ N, N-H ⋯ O, and C-H ⋯ O types of hydrogen bonds and C-H ⋯ π secondary bonding interactions in these crystalline solids. The Schiff bases have been screened for anticoagulant and antiplatelet aggregation activities. All the compounds showed procoagulant activity which shortens the clotting time of citrated human plasma in both platelet-rich plasma and platelet-poor plasma except the derivatives of L-methionine which showed anticoagulant activity by prolonging the clotting time. In addition, the compounds derived from benzyl cysteine and phenylalanine showed adenosine diphosphate induced antiplatelet aggregation activity, whereas others did not show any role. Moreover, all these compounds revealed non-hemolytic activity with red blood cells. Supplementary Information: The online version contains supplementary material available at 10.1007/s00706-022-02936-6.

Crystal structures of six 4-(4-nitro-phenyl)-piperazin-1-ium salts.

Six piperazinium salts, namely 4-(4-nitro-phenyl)-piperazin-1-ium 4-bromo-ben-zo-ate dihydrate, C10H14N3O2 +·C7H4BrO2 -·2H2O, (I), 4-(4-nitro-phenyl)-pi-per-a-zin-1-ium 4-iodo-benzoate dihydrate, C10H14N3O2 +·C7H4IO2 -·2H2O, (II), 4-(4-nitro-phenyl)-piperazin-1-ium 4-hy-droxy-benzoate monohydrate, C10H14N3O2 +·C7H5O3 -·H2O, (III), 4-(4-nitro-phenyl)-piperazin-1-ium 4-methyl-benzoate monohydrate, C10H14N3O2 +·C8H7O2 -·H2O, (IV), 4-(4-nitro-phenyl)-piperazin-1-ium 4-meth-oxy-benzoate hemihydrate, 2C10H14N3O2 +·2C8H7O3 -·H2O, (V), and 4-(4-nitro-phenyl)-piperazin-1-ium 4-eth-oxy-benzoate, 2C10H14N3O2 +·2C9H9O3 -, (VI), have been synthesized and their crystal structures solved by single-crystal X-ray diffraction, revealing that all of them crystallize in the triclinic space group P except for (V), which crystallizes in the monoclinic space group P21/c and has a disordered nitro group. Compounds (I) and (II) are isostructural. The crystal packing of (I)-(V) is constructed from organic chains formed by a combination of hydrogen bonds of type N-H⋯O and/or O-H⋯O and other weak inter-actions of type C-H⋯O and/or C-H⋯π, forming sheets, whereas (VI) shows a cationic and anionic-based layer structure.

Bi- and trimetallic complexes with macrocyclic xanthene-4,5-diNHC ligands.

Three different types of bimetallic NHC-metal complexes were synthesized, whose NHC units are attached at the 4,5-positions of xanthene. The NHC units are in close proximity and are designed such that each carbene coordinates one ML unit, while the chelation of one metal by two NHC is not possible. Several xanthene-((NHC)ML)2 complexes with ML = RhCl(cod), IrCl(cod), RhCl(CO)2, IrCl(CO)2, AuCl, AgCl, CuCl and Pd(allyl)Cl were synthesized and investigated.

Crystal structure studies of 4-ethyl-piperazin-1-ium 3,5-di-nitro-benzoate, 4-methyl-piperazin-1-ium 3,5-di-nitro-benzoate and 4-methyl-piperazin-1-ium 4-iodo-benzoate.

As part of our ongoing investigation on the chemical and biological properties of piperazinium salts, we synthesized three novel compounds: 1-ethyl-piperazinium 3,5-di-nitro-benzoate (I), 1-methyl-piperazinium 3,5-di-nitro-benzoate (II) and 1-methyl-piperazinium 4-iodo-benzoate (III). The crystal structures of these compounds are built up of organic layers formed by the strong connection between the mol-ecules by hydrogen bonds of type N-H⋯O. These layers are linked through N-H⋯O hydrogen bonds and C-H⋯O inter-actions or C-I⋯N halogen bonding, leading to the formation of a three-dimensional network.

Crystal structures of three N-acyl-hydrazone isomers.

The crystal structures of three isomers of (E)-4-chloro-N-{2-[2-(chloro-benzyl-idene)hydrazin-yl]-2-oxoeth-yl}-benzene-sulfonamide, namely, (E)-4-chloro-N-{2-[2-(2-chloro-benzyl-idene)hydrazin-yl]-2-oxoeth-yl}-benzene-sulfonamide (I), (E)-4-chloro-N-{2-[2-(3-chloro-benzyl-idene)hydrazin-yl]-2-oxoeth-yl}-benzene-sul-fon-amide (II) and (E)-4-chloro-N-{2-[2-(4-chloro-benzyl-idene)hydrazin-yl]-2-oxo-eth-yl}-benzene-sulfonamide (III), with the general formula C15H13Cl2N3O3S are described, with the chloro group in ortho, meta and para positions in the benzyl-idene benzene ring. All the three isomeric compounds crystallize in the centrosymmetric triclinic P space group with one mol-ecule each in the asymmetric unit and two mol-ecules in the unit cell. The dihedral angles between the two phenyl rings are 11.09 (14), 53.79 (18) and 72.37 (11)° in (I), (II) and (III), respectively. The central part of the mol-ecule (-C-N-N=C-) is almost linear with C-N-N-C torsion angles of 179.1 (2), -169.5 (3) and 178.5 (2)° for (I), (II) and (III), respectively. In all the three crystals, the mol-ecules form inversion dimers with R 2 2(8) ring motifs, which are further augmented by C-H⋯O inter-actions.

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.

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.