Structural, Hirshfeld surface and spectroscopic studies of the noncentrosymmetric 1-ethylpiperazinediium pentachloroantimonate (III) monohydrate

1-Ethylpiperazinediium pentachloroantimonate (III) monohydrate, C6H16N2SbCl5 center dot H2O, has been synthesized by the reaction of antimony trioxide (Sb2O3) and 1-ethylpiperazine in an aqueous solution of hydrochloric acid. The structure crystallizes in orthorhombic system, in the non-centrosymmetric space group Pca2(1) and consists of isolated [C6H16N2](2+) cations, square pyramidal [SbCl5](2-) anions and lattice water molecules. O-H center dot center dot center dot Cl hydrogen bonds link the [SbCl5](2-) anions and water molecules to form double chains stretching along the [101] direction. The chains in turn are linked to the organic cations via N-H center dot center dot center dot Cl, C-H center dot center dot center dot Cl, C-H center dot center dot center dot O and N-H center dot center dot center dot O hydrogen bonds to form a three-dimensional network. This structure presents an example of a general square pyramidal complex ion containing a stereo-chemically active lone pair of electrons. Solid state C-13 and N-15 CP-MAS NMR spectra are in agreement with the X-ray structure, and vibrational absorption bands were identified by infrared spectroscopy. DFT calculations allowed the attribution of the NMR peaks and IR absorption bands. The interactions variability of the two independent cations and ten chloride atoms is analyzed via Hirshfeld surface analysis. (C) 2016 Elsevier Masson SAS. All rights reserved.