Cesium Carbonate: Properties, Applications, And Synthesis

Introduction

Cesium carbonate (Cs2CO3) is an inorganic compound used in chemistry, materials science and various industrial processes. It appears as a white, hygroscopic powder. It dissolves readily in water and organic solvents. Owing to its strong basicity and solubility, cesium carbonate is employed as a catalyst, as a reagent in organic synthesis and as an additive in multiple electronic and optical applications.

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Chemical and Physical Properties

Cesium carbonate has the molecular formula Cs2CO3 and a molar mass of 325.82 g/mol. It is a white, hygroscopic powder that absorbs moisture from the air. It dissolves easily in water and forms a strongly basic solution, thereby meeting the requirements for reactions that need a strong base. The compound has a melting point of approximately 610 °C and decomposes on further heating.

Main Characteristics:

• Molecular Formula: Cs2CO3
• Molar Mass: 325.82 g/mol
• Appearance: White, hygroscopic powder
• Solubility: Highly soluble in water, methanol and other polar solvents
• Basicity: Strong base with a pKa value appropriate for deprotonation reactions
• Decomposition: Decomposes at elevated temperatures with the release of CO2

Synthesis of Cesium Carbonate

Cesium carbonate can be synthesised using various methods, including direct reactions and precipitation techniques:

1. Reaction of Cesium Hydroxide with Carbon Dioxide:
• CsOH + CO2 → Cs2CO3 + H2O
• In this procedure, carbon dioxide gas is bubbled through a cesium hydroxide solution, thereby causing the precipitation of cesium carbonate.
2. Reaction of Cesium Salts with Alkaline Carbonates:
• CsCl + Na2CO3 → Cs2CO3 + NaCl
• In this method, cesium chloride reacts with sodium carbonate followed by purification steps to yield pure cesium carbonate.

Applications of Cesium Carbonate

Due to its strong basicity, solubility and catalytic properties, cesium carbonate is applied in various fields, including organic synthesis, electronics and pharmaceutical research.

1. Organic Synthesis

Cesium carbonate is widely used as a base in organic chemistry for reactions that require a non-nucleophilic, strong base. Its primary roles include:

• Catalyst in Coupling Reactions: It is utilised in palladium-catalysed cross-coupling reactions such as Suzuki, Heck and Sonogashira reactions. These reactions are essential for the synthesis of complex organic molecules in pharmaceutical and materials science research.
• N-Alkylation and O-Alkylation Reactions: Cesium carbonate facilitates the alkylation of amines, alcohols and phenols; this yields ethers and secondary amines.
• Cyclisation Reactions: It promotes intramolecular cyclisation reactions that form heterocyclic and macrocyclic compounds.

2. Electronic and Optical Applications

Cesium carbonate is employed in advanced materials research, particularly in the manufacture of optoelectronic devices.

• Organic Light-Emitting Diodes (OLEDs): Cs2CO3 is used as the electron injection layer (EIL) in OLEDs, thereby enhancing electron transport and efficiency.
• Perovskite Solar Cells: It is incorporated as an additive in perovskite solar cells to improve efficiency and stability.
• Thin-Film Transistors: Cesium carbonate is applied as a dopant or interfacial layer in thin-film transistor technologies, thereby supporting charge transport.

3. Pharmaceutical Industry

• Synthesis of Pharmaceuticals: Cesium carbonate is used in pharmaceutical research for the development of new drug molecules. It is particularly appropriate for reactions that require selective deprotonation or nucleophilic substitutions.
• Peptide Coupling Reactions: In certain peptide bond formations, the use of cesium carbonate increases yield and selectivity.

4. Polymer Chemistry

• Polymer Functionalisation: Cs2CO3 is used to modify polymer surfaces and structures. This process enhances conductivity, thermal stability and mechanical performance.
• Catalyst for Polymerisation Reactions: Cs2CO3 functions as a catalyst in polymerisation processes, thereby facilitating the formation of high-performance polymers.

Safety and Handling

Although cesium carbonate is generally considered safe for use in laboratory and industrial settings, certain precautions should be observed:

• Hygroscopic Nature: It absorbs moisture from the air and should be stored in airtight containers to prevent degradation.
• Strong Alkalinity: It is a strong base and may cause skin or eye irritation. Appropriate personal protective equipment (PPE) such as gloves, safety goggles and a laboratory coat should be worn.
• Environmental Aspects: When disposing of cesium carbonate, local regulations must be followed to avoid contamination of water sources and ecosystems.

Overview Table for Cesium Carbonate

Conclusion

Cesium carbonate is a versatile compound with significant applications in organic synthesis, electronics, pharmaceuticals and materials science. Its strong basicity, high solubility and catalytic properties render it a useful reagent in various chemical transformations.

Stanford Advanced Materials (SAM) supplies high-purity cesium carbonate (Cs2CO3) for a range of applications, including organic synthesis, electronics and pharmaceuticals. Its solubility and basicity support performance in catalytic and optoelectronic applications. Choose Stanford Advanced Materials if you require a product that meets your specific requirements.

Reference:

[1] Cesium Carbonate. (09/01/2025). In Wikipedia. https://en.wikipedia.org/wiki/Caesium_carbonate