Cerium Iodide, Cerous Iodide, Cerium (III) Iodide, 7790-87-6

CERIUM IODIDE (CERIUM(III) IODIDE) 

Chemical Name: Cerium(III) Iodide / Cerium Triiodide
CAS Number: 7790-87-6
EC Number: 232-228-3
UN Number: 3077 (Environmentally hazardous substance)

1. PRODUCT IDENTIFICATION AND CHEMICAL IDENTITY

CHEMICAL STRUCTURE AND DESCRIPTION:

Cerium Iodide (CeI₃) is an inorganic compound composed of cerium in the +3 oxidation state and iodine. It is the iodide salt of cerium, appearing as a yellow to brownish-yellow crystalline solid . The compound adopts the plutonium(III) bromide (PuBr₃) crystal structure, containing 8-coordinate bicapped trigonal prismatic Ce³⁺ ions . Cerium iodide is highly hygroscopic and readily absorbs moisture from air, turning brown due to the liberation of iodine upon exposure . It is soluble in water, acetone, and polar organic solvents .

2. PHYSICAL AND CHEMICAL PROPERTIES

Cerium Iodide is a highly hygroscopic, yellow to brownish-yellow crystalline solid with a melting point of approximately 750-770°C . It is soluble in water, acetone, and other polar solvents. Due to its extreme sensitivity to air and moisture, it decomposes upon exposure, turning brown due to iodine liberation . The compound must be handled under inert atmosphere and stored in airtight containers.

3. SOLUBILITY PROFILE

Cerium Iodide is soluble in water and various organic solvents including acetone, tetrahydrofuran (THF), acetonitrile, and diethyl ether . In organic solvents, it forms solvated complexes that exhibit luminescent properties . Its solubility in aprotic organic solvents makes it valuable for organocerium chemistry applications.

4. CHEMICAL PROPERTIES AND REACTIONS

Cerium Iodide is a highly reactive Lewis acid that forms organocerium reagents when reacted with organolithium compounds. These reagents exhibit reduced basicity and enhanced nucleophilicity toward carbonyl groups, making them valuable in organic synthesis . The compound is extremely hygroscopic and decomposes in air, releasing iodine and turning brown . It exhibits solvoluminescence in organic solvents, with violet or blue emissions under UV irradiation, which can be used for trace water detection .

Key Chemical Reactions:

Organocerium Reagent Formation:
CeI₃ + RLi → RCeI₂ + LiI (forms reagents with reduced basicity)

Reaction with Air/Moisture:
CeI₃ + H₂O → CeOI + 2HI (decomposition in moist air, iodine liberation)

Direct Synthesis:
2Ce + 3I₂ → 2CeI₃ (at elevated temperatures) 

5. SPECIFICATIONS (TECHNICAL AND HIGH PURITY)

Cerium Iodide is available in various grades from technical (≥ 99%) to ultra-high purity (≥ 99.999%) . Ultra-dry grades with water content <100 ppm are essential for moisture-sensitive applications . High purity grades (99.9% and above) are preferred for research, optical, and organometallic applications where trace impurities and moisture significantly affect performance.

6. APPLICATIONS AND INDUSTRIAL USES

6.1. Organometallic and Organic Synthesis (Most Important Application)

Cerium Iodide is primarily used as a precursor for organocerium reagents in organic synthesis. When reacted with organolithium compounds, it forms organocerium reagents with reduced basicity and enhanced nucleophilicity toward carbonyl groups, enabling selective transformations . It also promotes aldol reactions and serves as a selective reducing agent in combination with LiAlH₄.

6.2. Electrochemical Energy Storage

Recent research has demonstrated that Cerium Iodide can serve as a bifunctional redox mediator in Li-O₂ batteries, where Ce³⁺ acts as a superoxide radical scavenger and I⁻ acts as a redox mediator, significantly improving cycle life .

6.3. Optical and Luminescence Applications

Cerium Iodide exhibits solvoluminescence in organic solvents, emitting violet or blue light under UV irradiation. This property can be utilized as a convenient luminescent sensor for detecting trace water in organic solvents with a detection limit of 0.1% (v/v) .

6.4. Materials Science and Ceramics

6.5. Research and Laboratory Applications

7. ALTERNATIVE / EQUIVALENT PRODUCTS

8. SECTOR SUITABILITY TABLE

9. COMMON NAMES

• Cerium salt

• Cerium triiodide

• White iodide crystal

• Cerium iodide powder

• Cerous iodide

• Rare earth iodide

10. PRODUCTION PROCESS

Reaction Equations:

Direct Synthesis:
2Ce + 3I₂ → 2CeI₃ (400-650°C) 

Mercury(II) Iodide Method:
2Ce + 3HgI₂ → 2CeI₃ + 3Hg 

Solution Method:
CeO₂ + 6HI → CeI₃ + I₂ + 3H₂O (with NH₄I, heated in vacuo) 

Production Types: Technical, high purity, and ultra-dry grades

Major Producing Countries: China, India, United States, Japan

Commercial Purity: Ranges from 99% to 99.999%

11. SAFETY AND TOXICOLOGY

SPECIAL WARNINGS: Cerium Iodide is a hazardous material that may cause skin and eye irritation, allergic skin reactions, and respiratory sensitization. It is classified as a reproductive toxicant (H360) that may damage fertility or the unborn child . Due to its extreme hygroscopicity, it decomposes upon moisture exposure, releasing iodine. The compound must be handled with appropriate personal protective equipment (gloves, safety goggles, dust mask) under inert atmosphere. Store locked up and dispose in accordance with regulations .

12. TRANSPORT INFORMATION

Cerium Iodide is classified as an environmentally hazardous substance under UN 3077. Release into the environment must be prevented during transport. Due to its sensitivity to moisture, shipping must be in airtight ampules or sealed containers under inert atmosphere.

13. REGULATORY INFORMATION

Cerium Iodide is registered in all major industrial markets. KKDİK registration is required for use in Turkey. It is classified under customs tariff code 2846.90.00.00.19. Due to its hazardous classification, proper import/export documentation and safety declarations are required.

14. STORAGE AND HANDLING

Handling Notes:

• CRITICAL: This compound is extremely hygroscopic and must be handled under inert atmosphere 

• Use a glove bag or dry box for all handling operations 

• Use airtight, moisture-proof containers after opening

• Avoid skin and eye contact (use protective gloves and safety goggles)

• Avoid dust formation and inhalation

• Store under nitrogen or argon 

• Use in well-ventilated areas or under fume hood

• Avoid exposure to moisture and air

15. FIRE-FIGHTING MEASURES

Cerium Iodide is not a flammable substance. In case of fire, protective clothing and SCBA must be used. Thermal decomposition may release toxic iodine fumes and cerium oxides.

16. ACCIDENTAL RELEASE MEASURES

In case of spillage, appropriate personal protective equipment must be worn. Handle under inert atmosphere to prevent decomposition. Clean up using dry methods. Environmental release must be prevented as it is classified as UN 3077.

17. FIRST AID MEASURES

Special Notes:

• Cerium iodide is classified as a reproductive toxicant (H360) 

• May cause sensitization by inhalation and skin contact 

• Medical personnel should be informed about iodide salt exposure

• In case of ingestion, do not induce vomiting due to possible aspiration risk

18. RAW MATERIALS AND DOWNSTREAM PRODUCTS

18.1. Raw Materials (Upstream)

18.2. Downstream Products

19. QUALITY CONTROL PARAMETERS

20. SUMMARY AND CRITICAL WARNINGS

SUMMARY:

Cerium Iodide (CeI₃, CAS 7790-87-6) is a yellow to brownish-yellow, highly hygroscopic crystalline solid. It is the iodide salt of cerium in the +3 oxidation state with a molecular weight of 520.83 g/mol. The compound has a melting point of approximately 750-770°C, is soluble in water and polar organic solvents (acetone, THF, acetonitrile), and adopts the PuBr₃ crystal structure. It is extremely sensitive to air and moisture, decomposing upon exposure with liberation of iodine.

Its most important application is as a precursor for organocerium reagents in organic synthesis, where it reacts with organolithiums to form reagents with reduced basicity and enhanced nucleophilicity . It also serves as a Lewis acid catalyst for aldol reactions and as a selective reducing agent in combination with LiAlH₄ . Emerging applications include use as a bifunctional redox mediator in Li-O₂ batteries to improve cycling performance  and as a luminescent sensor for trace water detection in organic solvents .

The compound is classified as a hazardous material with GHS H315 (skin irritation), H319 (eye irritation), H317 (allergic skin reaction), H334 (respiratory sensitization), and H360 (reproductive toxicity) . It is also classified as an environmentally hazardous substance under UN 3077. Due to its extreme hygroscopicity, it must be handled and stored under inert atmosphere (nitrogen/argon) in airtight containers .

Key Properties:

Major Application Areas:

Key Safety Points:

• HAZARDOUS: GHS07 and GHS08 classification

• SKIN/EYE IRRITANT: H315, H319 

• SENSITIZER: H317, H334 

• REPRODUCTIVE TOXICANT: H360 

• EXTREMELY HYGROSCOPIC: Must be stored under inert atmosphere 

• ENVIRONMENTALLY HAZARDOUS: UN 3077

• PROTECTIVE EQUIPMENT: Gloves, safety goggles, dust mask, protective clothing 

• STORAGE: Inert atmosphere, airtight, locked up 

CRITICAL WARNINGS:

1. EXTREME HYGROSCOPICITY: Cerium Iodide is extremely hygroscopic and turns brown when exposed to air due to iodine liberation . It must be stored under nitrogen or argon and handled in a glove bag or dry box .

2. REPRODUCTIVE TOXICANT: The compound is classified as a reproductive toxicant that may damage fertility or the unborn child (H360) . Strict handling precautions must be followed.

3. ORGANOCERIUM REAGENT PRECURSOR: Cerium Iodide is the preferred precursor for organocerium reagents in organic synthesis. These reagents exhibit reduced basicity and enhanced nucleophilicity toward carbonyl groups, enabling selective transformations .

4. SENSITIZATION HAZARD: May cause sensitization by inhalation and skin contact (H334, H317) . Avoid inhalation of dust and skin contact.

5. Li-O₂ BATTERY APPLICATION: Recent research demonstrates that CeI₃ can serve as a bifunctional redox mediator in Li-O₂ batteries, where Ce³⁺ acts as a superoxide radical scavenger and I⁻ acts as a redox mediator, significantly improving cycle life .

6. LUMINESCENT SENSOR: Commercial CeI₃ exhibits solvoluminescence in organic solvents and can be used as a convenient luminescent sensor for detecting trace water in organic solvents with a detection limit of 0.1% (v/v) .

7. HANDLING UNDER INERT ATMOSPHERE: All handling operations must be performed under inert atmosphere (nitrogen or argon) using a glove bag or dry box. Containers must be opened only in dry environments and resealed immediately .

8. CUSTOMS CLASSIFICATION: The correct customs tariff code is 2846.90.00.00.19. Correct classification is essential for international trade, with potential country-specific restrictions for rare earth compounds.

9. STORAGE SHELF LIFE: Due to its extreme sensitivity to moisture, shelf life is limited. Ultra-dry grades with water content <100 ppm are available for moisture-sensitive applications .

10. WASTE DISPOSAL: Dispose of contents and container in accordance with local, regional, national, and international regulations. Store locked up and handle as hazardous waste .

Important Disclaimer: This Technical Data Sheet (TDS) is for informational purposes only. The information provided is based on available data and is believed to be accurate. However, the user is solely responsible for determining the suitability of the product for their specific applications and for complying with all applicable regulations and safety requirements. For complete safety, handling, storage, and regulatory compliance information, always refer to the official Safety Data Sheet (SDS/MSDS) provided by the manufacturer/supplier. Users are responsible for testing the product in their own processes and applications. All local, national, and international regulations must be followed when working with Cerium Iodide. Due to its extreme hygroscopicity and hazardous classification, a detailed risk assessment and handling procedure must be established prior to use.