1,4-Dimethyl-piperazine-1,4-diium bis-(hexa-fluoro-phosphate) dihydrate

Area of Science:

• Crystallography
• Solid-state chemistry
• Molecular structure analysis

Background:

• Understanding the packing and interactions in molecular salts is crucial for materials science.
• Hydrated salts present unique challenges and opportunities due to water molecule incorporation.
• Piperazine derivatives are common in various chemical and pharmaceutical applications.

Purpose of the Study:

• To elucidate the crystal structure of the hydrated molecular salt C(6)H(16)N(2) (+)·2PF(6) (-)·2H(2)O.
• To analyze the cation conformation and orientation within the crystal lattice.
• To investigate the hydrogen bonding network involving cations, anions, and water molecules.

Main Methods:

• Single-crystal X-ray diffraction was employed to determine the molecular and crystal structure.
• Analysis of bond lengths, bond angles, and intermolecular interactions (hydrogen bonds).
• Symmetry operations, specifically crystallographic inversion, were used to describe the dication.

Main Results:

• The 1,4-dimethyl-piperazine-1,4-diium dication was confirmed, with both C-N bonds adopting equatorial orientations.
• The crystal structure is characterized by O-H⋯F and N-H⋯O hydrogen bonds, linking the components.
• No direct interactions were observed between the dication and the hexafluorophosphate anions.

Conclusions:

• The crystal structure provides insights into the self-assembly of hydrated molecular salts.
• The equatorial orientation of the C-N bonds influences the overall molecular conformation.
• Hydrogen bonding plays a significant role in stabilizing the crystal lattice, with water molecules acting as key linkers.