Bis(tetra-methyl-ammonium) oxalate monohydrate.

Area of Science:

• Crystallography
• Crystal Chemistry
• Materials Science

Background:

• Understanding the packing and interactions within crystalline solids is crucial for predicting material properties.
• Hydrated salts, particularly those with organic cations and inorganic anions, exhibit diverse structural motifs.
• The tetramethylammonium cation and oxalate anion are common building blocks in coordination chemistry and crystal engineering.

Purpose of the Study:

• To elucidate the crystal structure of the hydrated salt: 2(tetramethylammonium) oxalate monohydrate.
• To analyze the symmetry elements and atomic positions within the crystal lattice.
• To investigate the intermolecular interactions, specifically hydrogen bonding, that govern the crystal packing.

Main Methods:

• Single-crystal X-ray diffraction was employed to determine the three-dimensional crystal structure.
• Analysis of crystallographic data included identification of symmetry operations and atomic coordinates.
• Hydrogen bonding networks were identified and characterized using geometric parameters.

Main Results:

• The crystal structure reveals two independent tetramethylammonium cations, one oxalate anion, and one water molecule per asymmetric unit.
• All molecular components (cations, anion, water) occupy special positions with crystallographic site symmetry (m).
• Anion-water hydrogen bonding (O-H⋯O) results in the formation of a one-dimensional chain extending along the b-axis.

Conclusions:

• The crystal structure of 2(tetramethylammonium) oxalate monohydrate has been successfully determined.
• The presence of site symmetry influences the orientation and interactions of the molecular units.
• The observed hydrogen bonding network dictates the supramolecular architecture, forming a characteristic chain structure.