Synthesis, properties and supramolecular structure of piperazinediium thiosulfate monohydrate

Abstract

Aqueous reaction of ammonium thiosulfate with piperazine (pip) results in the formation of the title compound (pipH(2))[S2O3].H2O 1 (pipH(2) = piperazinediium) in good yield. 1 was characterized by elemental analysis, IR. Raman and MAR spectra, X-ray powder pattern and its structure was determined.On heating at 100 degrees C, 1 transforms to anhydrous piperazinediium thiosulfate 2, which can be rehydrated to the monohydrate on exposure to moisture. The structure of 1 consists of two crystallographically independent piperazinediium (pipH(2))(2+) cations located on inversion centers, a thiosulfate anion and a lattice water. The organic cations, thiosulfate anion and lattice water are linked by six varieties of hydrogen bond namely O-H...O, O-H...S, N-H...O, N-H...S, C-H...O and C-H...S, leading to the formation of alternating layers of (pipH(2))(2+) cations and water linked thiosulfate chains. A comparative study of several compounds charge balanced by the piperazinediium cation is described.