Crystal structure studies and Hirshfeld surface analysis of 4-(di-methyl-aza-nium-yl)-2-hy-droxy-anilinium dichloride monohydrate at 90†K.

The crystal structure and a Hirshfeld surface analysis of the substituted anilinium salt 4-(di-methyl-aza-nium-yl)-2-hy-droxy-anilinium dichloride monohydrate, C8H14N2O+·2Cl-·H2O, at low temperature (90 K) are presented. The organic cation is essentially planar: the r.m.s. deviation of its non-hydrogen atoms (aside from the two methyl groups) is 0.0045 Å. The methyl carbons are 1.3125 (12) Šand 1.1278 (12) Šeither side of the mean plane. The crystal packing involves extensive hydrogen bonding of types O-H⋯Cl, N-H⋯Cl, N-H⋯OW, and OW-HW⋯Cl (where W = water), which arrange into chains of R 2 4(12) motifs that combine to form corrugated layers parallel to (10). Atom-atom contacts for the cation primarily involve hydrogen, leading to the most abundant coverage percentages being 51.3% (H⋯H), 23.0% (H⋯Cl), 12.9% (H⋯O), and 9.7% (C⋯H).

Crystal structures of four organic salts of trihexyphenidyl at 90†K.

The syntheses and crystal structure studies of four organic salts of trihexyphenidyl, viz., trihexyphenidylium [1-(3-cyclo-hexyl-3-hy-droxy-3-phenyl-prop-yl)piperidin-1-ium] 4-nitro-benzoate, C20H32NO+·C7H4NO4 - (I), trihexyphenidylium 4-hy-droxy-benzoate, C20H32NO+·C7H5O- (II), trihexyphenidylium 4-bromo-benzoate, C20H32NO+·C7H4BrO2 - (III), and trihexyphenidylium thio-phene-2-carboxyl-ate hemihydrate, 2C20H32NO+·2C5H3O2S-·H2O (IV), con-ducted at 90 K are described. Structures I, II, and III are solvent free with one cation-anion pair per asymmetric unit, while IV crystallizes as a hemihydrate, having two cation-anion pairs and one water of crystallization in its asymmetric unit. Structures I and III exhibit configurational disorder of the cation. Structure IV also exhibits disorder, but only of the thio-phene-2-carboxyl-ate anions. Structure II is a non-merohedric twin by a twofold rotation about [403]. The main supra-molecular motifs in I, II, and III are similar R 2 2(10) rings between cation-anion pairs, although their packing within the crystals is distinct. As a consequence of having two cation-anion pairs and a water mol-ecule in its asymmetric unit, the packing in IV is by far the most complex of the four structures, its hydrogen-bonding patterns being quite different from I, II, or III. In all the crystals studied, N-H⋯O, O-H⋯O, and C-H⋯O inter-actions are observed, plus C-H⋯Br close contacts for III.

The synthesis, crystal structure and spectroscopic analysis of (E)-3-(4-chloro-phen-yl)-1-(2,3-di-hydro-benzo[b][1,4]dioxin-6-yl)prop-2-en-1-one.

The synthesis, crystal structure and spectroscopic analysis of (E)-1-(2,3-di-hydro-benzo[b][1,4]dioxin-6-yl)-3-(4-chloro-phen-yl)prop-2-en-1-one (C17H13ClO3), a substituted chalcone, are described. The overall geometry of the mol-ecule is largely planar (r.m.s. deviation = 0.1742 Å), but slightly kinked, leading to a dihedral angle between the planes of the benzene rings at either side of the mol-ecule of 8.31 (9)°. In the crystal, only weak inter-actions determine the packing motifs. These include C-H⋯O and C-H⋯Cl hydrogen bonds and π-π overlap of aromatic rings.

Crystal structure and Hirshfeld-surface analysis of a monoclinic polymorph of 2-amino-5-chloro-benzo-phenone oxime at 90†K.

The synthesis and crystal structure of a monoclinic polymorph of 2-amino-5-chloro-benzo-phenone oxime, C13H11ClN2O, are presented. The mol-ecular conformation results from twisting of the phenyl and 2-amino-5-chloro benzene rings attached to the oxime group, which subtend a dihedral angle of 80.53 (4)°. In the crystal, centrosymmetric dimers are formed as a result of pairs of strong O-H⋯N hydrogen bonds. A comparison is made to a previously known triclinic polymorph, including differences in atom-atom contacts obtained via a Hirshfeld-surface analysis.

Synthesis and crystal structure studies of 5-(tri-fluoro-meth-yl)-1,3,4-thia-diazol-2(3H)-one at 180†K.

The synthesis and crystal structure of C3HF3N2OS, systematic name 5-(tri-fluoro-meth-yl)-1,3,4-thia-diazol-2(3H)-one (5-TMD-2-one), a compound containing the pharmacologically important heterocycle 1,3,4-thia-diazole, is presented. The asymmetric unit comprises six independent mol-ecules (Z' = 6), all of which are planar. The r.m.s. deviations from each mean plane range from 0.0063 to 0.0381 Å, not including the CF3 fluorine atoms. Within the crystal, two of the mol-ecules form hydrogen-bonded dimers that in turn combine with inversion-related copies to form tetra-meric constructs. Similar tetra-mers, but lacking inversion symmetry, are formed by the remaining four mol-ecules. The tetra-mers are linked into tape-like motifs by S⋯O and O⋯O close contacts. The environments of each symmetry-independent mol-ecule were compared via a Hirshfeld surface analysis. The most abundant atom-atom contacts are between fluorine atoms, while the strongest result from N-H⋯O hydrogen bonds.

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.

Synthesis, crystal structure and Hirshfeld surface analysis of N-(4-fluoro-phen-yl)-N-isopropyl-2-(methyl-sulfon-yl)acetamide.

The synthesis and crystal structure of the title compound, C12H16FNO3S, which is related to the herbicide flufenacet, are presented. The dihedral angle between the amide group and the fluorinated benzene ring is 87.30 (5)° and the N-C-C-S torsion angle defining the orientation of the methyl-sulfonyl substituent relative to the amide group is 106.91 (11)°. In the crystal, inversion-related mol-ecules form dimers as a result of pairwise C-H⋯O hydrogen bonds, which appear to be reinforced by short O⋯π contacts [O⋯Cg = 3.0643 (11) Å]. A Hirshfeld surface analysis was used to qu-antify the various types of inter-molecular contacts, which are dominated by H atoms.

Syntheses, crystal structures and Hirshfeld surface analyses of four mol-ecular salts of amitriptynol.

The syntheses and crystal structures of four salts of amitriptynol (C20H25NO) with different carb-oxy-lic acids are described. The salts formed directly from solutions of amitriptyline (which first hydrolysed to amitriptynol) and the cor-responding acid in aceto-nitrile to form amitriptynolium [sys-tem-atic name: (3-{2-hy-droxy-tri-cy-clo[9.4.0.03,8]penta-deca-1(11),3,5,7,12,14-hexa-en-2-yl}pro-pyl)di-methyl-az-an-ium] 4-meth-oxy-benzoate monohydrate, C20H26NO+·C8H7O3 -·H2O, (I), ami-triptynolium 3,4-di-meth-oxy-benzoate trihydrate, C20H26NO+·C9H9O4 -·3H2O, (II), amitriptynolium 2-chloro-benzoate, C20H26NO+·C7H4ClO2 -, (III), and amitriptynolium thio-phene-2-carboxyl-ate monohydrate, C20H26NO+·C5H3O2S-·H2O, (IV). Compound (III) crystallizes with two cations, two anions and six water mol-ecules in the asymmetric unit. The different conformations of the amitriptynolium cations are determined by the torsion angles in the di-methyl-amino-propyl chains and the -CH2-CH2- bridge between the benzene rings in the tricyclic ring system, and are complicated by disorder of the bridging unit in II and III. The packing in all four salts is dominated by N-H⋯O and O-H⋯O hydrogen bonds. Hirshfeld surface analyses show that the amitriptynolium cations make similar inter-species contacts, despite the distinctly different packing in each salt.

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 and crystal structures of four 4-(4-meth-oxy-phen-yl)piperazin-1-ium salts: tri-fluoro-acetate, 2,3,4,5,6-penta-fluoro-benzoate, 4-iodo-benzoate, and a polymorph with 4-methyl-benzoate.

Syntheses and X-ray crystal structures of four 4-(4-meth-oxy-phen-yl)piperazin-1-ium (MeOPP) salts, with 2,2,2-tri-fluoro-acetate, C11H17N2O+·C2F3O2 - (I), 2,3,4,5,6-penta-fluoro-benzoate, C11H17N2O+·C7F5O2 -·H2O (II), 4-iodo-benzoate C11H17N2O+·C7H4IO2 -·H2O (III), and 4-methyl-benzoate, C11H17N2O+·C8H7O2 -·H2O (IV) anions are presented. The salts form directly from equimolar qu-anti-ties of N-(4-meth-oxy-phen-yl)piperazine and the corresponding organic acid in methanol and crystallize from 1:1 methanol/ethyl acetate. Salt I is anhydrous whereas II, III, and IV are all monohydrates. In all cases, the MeOPP cation conformation is determined by the torsion about the N-C bond between the piperazinium and 4-meth-oxy-benzene rings. Crystal packing in each structure is largely dictated by N-H⋯O and (in II, III, and IV) O-H⋯O hydrogen bonds, although each also features weak C-H⋯O-type hydrogen bonds. Salt II also has π-π-stacking inter-actions between cation and anion arene rings, and III exhibits I⋯I close contacts.

Syntheses and crystal structures of four 4-(4-nitro-phen-yl)piperazinium salts with hydrogen succinate, 4-amino-benzoate, 2-(4-chloro-phen-yl)acetate and 2,3,4,5,6-penta-fluoro-benzoate anions.

The syntheses and crystal structures are presented for four organic salts of the 4-(4-nitro-phen-yl)piperazinium cation, namely, 4-(4-nitro-phen-yl)piperazinium hydrogen succinate, C10H14N3O2 +·C4H5O4 - (I), 4-(4-nitro-phen-yl)piperazinium 4-amino-benzoate monohydrate, C10H14N3O2 +·C7H6NO2 -·H2O (II), 4-(4-nitro-phen-yl)piperazinium 2-(4-chloro-phen-yl)acetate, C10H14N3O2 +·C8H6ClO2 - (III) and 4-(4-nitro-phen-yl)piperazinium 2,3,4,5,6-penta-fluoro-benzoate, C10H14N3O2 +·C7F5O2 - (IV). The salts form from mixtures of N-(4-nitro-phen-yl)piperazine and the corresponding acid [succinic acid (I), 4-amino-benzoic acid (II), 2-(4-chloro-phen-yl)acetic acid (III) and 2,3,4,5,6-penta-fluoro-benzoic acid (IV)] in mixed solvents of methanol and ethyl acetate. Salts I, III, and IV are anhydrous, whereas II is a monohydrate. In each structure, the overall conformation of the cation is determined by the disposition of the exocyclic N-C bond of the piperazine ring (either axial or equatorial) and twists about the N-C bond between the piperazine ring and its attached 4-nitro-phenyl ring. The packing motifs in each structure are quite different, though all are dominated by strong N-H⋯O hydrogen bonds, which are augmented in I and II by O-H⋯O hydrogen bonds, and in III by a π-π stacking inter-action between inversion-related 4-nitro-phenyl groups.

Crystal structure of the insecticide ethiprole (C13H9Cl2F3N4OS): a case study of whole-mol-ecule configurational disorder.

The crystal structure of ethiprole {systematic name: 5-amino-1-[2,6-di-chloro-4-(tri-fluoro-meth-yl)phen-yl]-4-ethane-sulfinyl-1H-imidazole-3-carbo-nitrile}, C13H9Cl2F3N4OS, a phenyl-pyrazole-based insecticide, is presented. The pyrazole ring carries four substituents: an N-bound 2,6-di-chloro-4-tri-fluoro-methyl-phenyl ring and C-bound amine, ethane-sulfinyl, and cyano groups. The sulfur atom of the ethane-sulfinyl group is trigonal-pyramidal and stereogenic. The structure exhibits whole-mol-ecule configurational disorder due to superposition of enanti-omers. The crystal packing is dominated by strong N-H⋯O and N-H⋯N hydrogen bonds, which form R 4 4(18) and R 2 2(12) ring motifs. Since the ethiprole mol-ecule is quite small, and structure solution and refinement were straightforward, the structure presents a convenient instructional example for modelling whole-body disorder of a non-rigid mol-ecule. To this end, a step-by-step overview of the model-building and refinement process is also given. The structure could form the basis of a useful classroom, practical, or workshop-style example.

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.

3-Methyl-5-(4-methyl-phen-oxy)-1-phenyl-1H-pyrazole-4-carbaldehyde.

In the title compound, C18H16N2O2, the phenyl and pyrazole rings subtend a dihedral angle of 22.68 (8)°. The packing of the title compound features aromatic π-π stacking and weak C-H⋯π inter-actions.

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.

Synthesis and crystal structure of 2-chloro-1-(3-hy-droxy-phen-yl)ethanone.

The structure of 2-chloro-1-(3-hy-droxy-phen-yl)ethanone, C8H7ClO2, an α-halo-ketone is described. The mol-ecule is planar (r.m.s. deviation = 0.0164 Å) and in the crystal, inversion-symmetric dimers are formed as a result of pairs of strong O-H⋯O and weak C-H⋯O hydrogen bonds. A brief comparison is made with structurally related compounds deposited in the CSD. In addition, the synthesis and some spectroscopic details are presented.

Synthesis, spectroscopic and crystal structure studies of N-{3-cyano-1-[2,6-di-chloro-4-(tri-fluoro-meth-yl)phen-yl]-4-(ethyl-sulfan-yl)-1H-pyrazol-5-yl}-2,2,2-tri-fluoro-acetamide.

The structure of the title compound, C15H8N4Cl2F6OS, a phenyl-pyrazole-based insecticide related to ethiprole, fipronil, and derivatives thereof is presented. The pyrazole ring has four chemically diverse substituents, namely a nitro-gen-bound 2,6-di-chloro-4-tri-fluoro-methyl-phenyl and carbon-bound cyano, ethyl-sulfanyl, and 2,2,2-tri-fluoro-acetamide groups. The pyrazole and phenyl rings are perpendicular, subtending a dihedral angle of 89.80 (5)°. In the crystal, strong N-H⋯O hydrogen bonds link the mol-ecules into chains that extend parallel to the a-axis.

5-(4-Fluoro-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.

In the title compound, C28H22FN3OS, four rings are almost coplanar, with the fluorophenyl ring substantially twisted. In the extended structure, aromatic π-π stacking inter-actions between the pyrazole ring and the tolyl ring link the mol-ecules into centrosymmetric dimers.

3-(3-Nitro-phen-yl)-1-[4-(prop-2-yn-yloxy)phen-yl]prop-2-en-1-one.

The structure of the title compound, C18H13NO4, shows that the whole mol-ecule is almost planar but with a dihedral angle between the two phenyl rings of 19.22 (5)°. The mol-ecules are linked by C-H⋯O inter-actions, forming sheets in the (21) plane.

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.