Abstract
Syntheses and X-ray crystal structures of four 4-(4-methoxyphenyl)piperazin-1-ium (MeOPP) salts, with 2,2,2-trifluoroacetate, C11H17N2O+·C2F3O2
− (I), 2,3,4,5,6-pentafluorobenzoate, C11H17N2O+·C7F5O2
−·H2O (II), 4-iodobenzoate C11H17N2O+·C7H4IO2
−·H2O (III), and 4-methylbenzoate, C11H17N2O+·C8H7O2
−·H2O (IV) anions are presented. The salts form directly from equimolar quantities of N-(4-methoxyphenyl)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-methoxybenzene 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 interactions between cation and anion arene rings, and III exhibits I...I close contacts.
Publisher
International Union of Crystallography (IUCr)
Subject
Condensed Matter Physics,General Materials Science,General Chemistry