Lithium Bicarbonate
[CAS# 5006-97-3]

Identification

• Classification: Food additive >> Nutrition supplements >> Inorganic salts
• Name: Lithium Bicarbonate
• Synonyms: lithium hydrogen carbonate
• Molecular Formula: CHLiO₃
• Molecular Weight: 67.96
• CAS Registry Number: 5006-97-3
• EC Number: 233-818-3
• SMILES: [Li+].C(=O)(O)[O-]

Discovory and Applicatios

Lithium bicarbonate is an inorganic compound with the empirical formula LiHCO₃. It is the lithium salt of bicarbonic acid and exists as a white, crystalline solid under specific conditions. Lithium bicarbonate is considered chemically unstable under ambient temperature and pressure, and it is typically encountered only in aqueous solution or under special laboratory conditions. Unlike more stable alkali metal bicarbonates such as sodium or potassium bicarbonate, lithium bicarbonate readily decomposes into lithium carbonate (Li₂CO₃), carbon dioxide (CO₂), and water (H₂O).

The discovery and understanding of lithium bicarbonate are closely tied to the study of lithium salts and their chemical equilibria in aqueous media. In the 19th century, lithium compounds were of interest due to their unique properties and relatively light atomic mass. Early studies on lithium salts included investigations into their formation, solubility, and reactivity, particularly in comparison to other group 1 alkali metals. Lithium bicarbonate was identified as a transient intermediate during the dissolution of carbon dioxide in aqueous lithium carbonate solutions.

Due to its instability in solid form, lithium bicarbonate has no direct commercial or industrial applications as an isolated compound. However, its formation and decomposition play a role in processes involving lithium carbonate and carbon dioxide under aqueous conditions. In water, when carbon dioxide is bubbled through a lithium carbonate solution, lithium bicarbonate may briefly form in solution before converting back to lithium carbonate upon warming or with the removal of CO₂. This reversible equilibrium is of importance in understanding the solubility and reactivity of lithium salts in various environmental and industrial processes.

In the pharmaceutical and medical fields, lithium compounds, particularly lithium carbonate and lithium citrate, are well known for their use in the treatment of bipolar disorder and other psychiatric conditions. Although lithium bicarbonate itself is not used therapeutically, its chemical behavior is relevant to the formulation and stability of lithium-containing drug preparations. In buffered solutions, the equilibrium between carbonate, bicarbonate, and CO₂ influences the pH and solubility characteristics of lithium drugs.

Analytically, lithium bicarbonate solutions have been studied in the context of solution thermodynamics and carbonate chemistry. Researchers have examined the equilibria involving bicarbonate and carbonate ions in lithium systems to better understand ion pairing, solubility products, and the thermodynamic properties of lithium salts. These studies are relevant to various scientific and engineering disciplines, including geochemistry, where lithium-bearing mineral waters and brines may contain bicarbonate species under certain conditions.

In recent years, interest in lithium chemistry has surged due to the demand for lithium in battery technology. While lithium bicarbonate does not play a role in lithium-ion batteries directly, understanding the full range of lithium salts and their behavior in aqueous and non-aqueous media contributes to broader research in energy storage and electrochemistry.

In summary, lithium bicarbonate is a chemically transient species primarily observed in aqueous solution under specific conditions. It does not have direct practical applications as a stable compound but remains of scientific interest due to its role in lithium carbonate equilibria and carbonate system chemistry. Its presence and reactivity contribute to the broader understanding of lithium's chemical properties, particularly in aqueous environments and in the context of lithium salt formulation.

References

2005. Hypothalamic-pituitary-adrenal Axis and Bipolar Disorder. The Psychiatric clinics of North America, 28, 2.
DOI: 10.1016/j.psc.2005.01.005

2005. Magnetic Resonance Findings in Bipolar Disorder. The Psychiatric clinics of North America, 28, 2.
DOI: 10.1016/j.psc.2005.01.006

2005. Treatment of Bipolar Depression. The Psychiatric clinics of North America, 28, 2.
DOI: 10.1016/j.psc.2005.02.003