Structure of dipotassium hydrogen citrate

Area of Science:

• Crystallography
• Inorganic Chemistry
• Structural Chemistry

Background:

• Dipotassium hydrogen 2-hydroxy-1,2,3-propanetricarboxylate, a salt of citric acid, is commonly used in various applications.
• Understanding its solid-state structure is crucial for predicting its chemical behavior and properties.

Purpose of the Study:

• To determine the crystal structure of dipotassium hydrogen 2-hydroxy-1,2,3-propanetricarboxylate.
• To elucidate the ionization state and hydrogen bonding network within the crystal lattice.
• To characterize the coordination environment of potassium ions.

Main Methods:

• Single-crystal X-ray diffraction was employed to analyze the crystal structure.
• Structural data was refined to obtain precise atomic coordinates and bond parameters.

Main Results:

• The crystal structure determination confirmed ionization at the central and one terminal carboxyl group of the citrate molecule.
• Citrate ions participate in both intramolecular and intermolecular hydrogen bonds, forming a complex network.
• Each potassium (K) ion is coordinated by eight oxygen atoms from multiple citrate ions, with metal-oxygen distances ranging from 2.706 to 3.136 Å.

Conclusions:

• The crystal structure provides detailed insights into the ionic and hydrogen bonding arrangements in dipotassium hydrogen citrate.
• The coordination number of eight for potassium ions highlights its complex interactions within the crystal lattice.
• This structural information is fundamental for understanding the chemical and physical properties of this compound.