Abstract
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 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 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.
Funder
National Science Foundation, Directorate for Mathematical and Physical Sciences
Publisher
International Union of Crystallography (IUCr)
Subject
Condensed Matter Physics,General Materials Science,General Chemistry