The crystal packing is characterized by an alternation of organic
and inorganic molecules (Fig. 2). The organic cations are joined to
[SbCl5]2 anions through N–H Cl and O–H Cl hydrogen bonds
(Fig. 4) and the hydrogen-bonding influence is clearly visible in
the differences in lengths of the equatorial Sb–Cl bonds (Table 3).
All the piperazine donor groups are involved in hydrogen bonding
formation towards the chlorine atoms, as reported in Table 3, the
NH2 group forming one single and one bifurcated interactions.
The final crystal architecture is characterized by a three-dimensional network of N/O–H Cl interactions (Fig. 2) with a number
of weaker C–H Cl/O hydrogen bonds contributing to its
robustness.