Trisodium citrate, Na3(C6H5O7).

Area of Science:

• Inorganic Chemistry
• Crystallography
• Materials Science

Background:

• Trisodium citrate is a widely used food additive and chelating agent.
• Understanding its crystal structure is crucial for its applications and stability.
• Previous structural data may be incomplete or lack atomic-level detail.

Purpose of the Study:

• To elucidate the detailed crystal structure of anhydrous trisodium citrate.
• To investigate the coordination environment of sodium cations within the crystal lattice.
• To characterize the hydrogen bonding network and overall framework architecture.

Main Methods:

• Synchrotron X-ray powder diffraction for data collection.
• Density Functional Theory (DFT) for structural optimization.
• Analysis of coordination polyhedra and intermolecular interactions.

Main Results:

• The crystal structure features two independent five-coordinate and one six-coordinate sodium cations.
• Sodium polyhedra ([NaO5] and [NaO6]) form a three-dimensional framework through shared edges and corners.
• Channels parallel to the a and b axes accommodate citrate anions, with specific intra- and intermolecular hydrogen bonds identified.

Conclusions:

• The study provides a precise atomic-level description of anhydrous trisodium citrate.
• The determined structure explains the stability and packing of the compound.
• This detailed structural insight can inform future applications and modifications of trisodium citrate.