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.
|Number of pages||6|
|Journal||Acta Crystallographica Section E: Crystallographic Communications|
|Issue number||Pt 4|
|State||Published - Mar 23 2023|
Bibliographical noteFunding Information:
One of the authors (V) is grateful to the DST–PURSE Project, Vijnana Bhavana, UOM for providing research facilities. HSY thanks UGC for a BSR Faculty fellowship for three years.
© 2023 International Union of Crystallography. All rights reserved.
- crystal structure
- hydrogen bonding
- iodine–iodine close contacts
- piperazinium salt
ASJC Scopus subject areas
- Chemistry (all)
- Materials Science (all)
- Condensed Matter Physics