The residual persistent plaque burden predicts the restenosis of drug-eluting stents

Bis(piperazine-1,4-diium) pentachloroantimonate (III) monohydrate, has been synthesized and characterized by X-ray diffraction at 293 K, thermogravimetric analysis (TGA), differential thermal analysis (DTA), IR and Raman measurements. It crystallizes in the monoclinic system with space group P21/n. The unit cell dimensions are: a = 9.5409(2) Ǻ, b = 14.1455(1) Ǻ, c = 10.0525(7) Ǻ, β = 99.113(8)°, with Z = 4. The molecule of this compound consists of piperazine-1,4-diium cation, [SbCl5]2− anions and water molecules. The distorted [SbCl5]2− square pyramids sharing two common Cl atoms are held together making bioctahedra of the form [Sb2Cl10]4−. The compound is stabilized by intermolecular N–H⋯Cl, O–H⋯Cl and N–H⋯O hydrogen bridge bonds. Analysis of dielectric spectroscopy permitted identification of a phase transitions at: 70 K. At 372 K dehydration takes place, while at 509 K the process of decomposition starts [24]. The 1H NMR measurements were performed in a broad temperature range. The data are interpreted in terms of different dynamics of piperazine cation and crystallization water in different environments.