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-cyclohexyl-3-hydroxy-3-phenylpropyl)piperidin-1-ium] 4-nitrobenzoate, C20H32NO+·C7H4NO4− (I), trihexyphenidylium 4-hydroxybenzoate, C20H32NO+·C7H5O− (II), trihexyphenidylium 4-bromobenzoate, C20H32NO+·C7H4BrO2− (III), and trihexyphenidylium thiophene-2-carboxylate hemihydrate, 2C20H32NO+·2C5H3O2S−·H2O (IV), conducted 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 thiophene-2-carboxylate anions. Structure II is a non-merohedric twin by a twofold rotation about [403]. The main supramolecular motifs in I, II, and III are similar R22(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 molecule 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 interactions are observed, plus C—H...Br close contacts for III

The synthesis, crystal structure and spectroscopic analysis of (E)-3-(4-chlorophenyl)-1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)prop-2-en-1-one

The synthesis, crystal structure and spectroscopic analysis of (E)-1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3-(4-chlorophenyl)prop-2-en-1-one (C17H13ClO3), a substituted chalcone, are described. The overall geometry of the molecule 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 molecule of 8.31 (9)°. In the crystal, only weak interactions 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-chlorobenzophenone oxime at 90 K

The synthesis and crystal structure of a monoclinic polymorph of 2-amino-5-chlorobenzophenone oxime, C13H11ClN2O, are presented. The molecular 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

Syntheses, crystal structures and Hirshfeld surface analyses of four molecular salts of amitriptynol

The syntheses and crystal structures of four salts of amitriptynol (C20H25NO) with different carboxylic acids are described. The salts formed directly from solutions of amitriptyline (which first hydrolysed to amitriptynol) and the corresponding acid in acetonitrile to form amitriptynolium [systematic name: (3-{2-hydroxytricyclo[9.4.0.03,8]pentadeca-1(11),3,5,7,12,14-hexaen-2-yl}propyl)dimethylazanium] 4-methoxybenzoate monohydrate, C20H26NO+·C8H7O3−·H2O, (I), amitriptynolium 3,4-dimethoxybenzoate trihydrate, C20H26NO+·C9H9O4−·3H2O, (II), amitriptynolium 2-chlorobenzoate, C20H26NO+·C7H4ClO2−, (III), and amitriptynolium thiophene-2-carboxylate monohydrate, C20H26NO+·C5H3O2S−·H2O, (IV). Compound (III) crystallizes with two cations, two anions and six water molecules in the asymmetric unit. The different conformations of the amitriptynolium cations are determined by the torsion angles in the dimethylamino-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

Synthesis, crystal structure and Hirshfeld surface analysis of N-(4-fluorophenyl)-N-isopropyl-2-(methylsulfonyl)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 methylsulfonyl substituent relative to the amide group is 106.91 (11)°. In the crystal, inversion-related molecules 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 quantify the various types of intermolecular contacts, which are dominated by H atoms

Synthesis and crystal structure studies of 5-(trifluoromethyl)-1,3,4-thiadiazol-2(3H)-one at 180 K

The synthesis and crystal structure of C3HF3N2OS, systematic name 5-(trifluoromethyl)-1,3,4-thiadiazol-2(3H)-one (5-TMD-2-one), a compound containing the pharmacologically important heterocycle 1,3,4-thiadiazole, is presented. The asymmetric unit comprises six independent molecules (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 molecules form hydrogen-bonded dimers that in turn combine with inversion-related copies to form tetrameric constructs. Similar tetramers, but lacking inversion symmetry, are formed by the remaining four molecules. The tetramers are linked into tape-like motifs by S...O and O...O close contacts. The environments of each symmetry-independent molecule 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