Ammonium Cerium Nitrate, Ceric Ammonium Nitrate, Diammonium Cerium Nitrate, CAN, 16774‑21‑3

Ammonium Cerium Nitrate, Ceric Ammonium Nitrate, Diammonium Cerium Nitrate, CAN, 16774‑21‑3

AMMONIUM CERIUM(IV) NITRATE (CAN) 

Chemical Name: Ammonium Cerium(IV) Nitrate / Ceric Ammonium Nitrate / Diammonium Cerium Nitrate
CAS Number: 16774-21-3
EC Number: 240-827-6
HS Code: 283429

1. PRODUCT IDENTIFICATION AND CHEMICAL IDENTITY

2. CHEMICAL STRUCTURE AND EXPLANATION

Chemical Structure and Bonding:

Ammonium Cerium(IV) Nitrate (CAN) is a complex ionic compound composed of two Ammonium (NH₄⁺) cations, one Cerium (Ce⁴⁺) cation, and six Nitrate (NO₃⁻) anions. Cerium is in the +4 oxidation state (tetravalent) in this compound. This is the highest oxidation state of cerium and imparts strong oxidizing properties to the compound. The characteristic orange-red color arises from the charge transfer complex formed between Ce⁴⁺ ions and nitrate ligands.

Molecular Formula Representation:

(NH₄)₂Ce(NO₃)₆

This formula indicates the following structure:

• 2 Ammonium ions (NH₄⁺): Outer sphere cations.

• 1 Cerium ion (Ce⁴⁺): Central metal atom.

• 6 Nitrate groups (NO₃⁻): Ligands coordinated to the cerium ion (two ionic, four coordinative).

Crystal Structure and Ionic Arrangement:

In the crystal structure, the Ce⁴⁺ ion is coordinated by nitrate groups (typically 12-coordinate). Nitrate ligands are arranged around the cerium center, while ammonium ions serve as charge-balancing cations in the crystal lattice. This structure imparts high solubility and strong oxidizing properties to the compound.

Simplified Ionic Representation:

        NH₄⁺   NH₄⁺   NO₃⁻
          \     |     /
           [Ce(NO₃)₆]²⁻
          /     |     \
        NO₃⁻   NO₃⁻   NO₃⁻

(An ionic crystal lattice composed of 2 NH₄⁺ ions and 1 [Ce(NO₃)₆]²⁻ complex anion)

Structural Properties:

Thermal Decomposition:

CAN decomposes sequentially upon heating:

(NH₄)₂Ce(NO₃)₆ → CeO₂ + 2 N₂O + 4 HNO₃ (approximately 100-150°C)

At higher temperatures, it converts to cerium oxide (CeO₂) and nitrogen oxides (NOx).

3. PHYSICAL AND CHEMICAL PROPERTIES

Important Physical Notes:

• CAN has a characteristic orange-red color due to the charge transfer complex between Ce⁴⁺ ions and nitrate ligands.

• It is highly hygroscopic and rapidly absorbs moisture from the air, requiring special packaging and storage conditions. Moisture absorption can cause color change and product degradation.

• It has high solubility in water and polar organic solvents (methanol, acetonitrile), making it suitable for various applications.

• It is a strong oxidizing agent; contact with organic materials presents a fire and explosion hazard.

• High purity grades (≥ 98.5%) are available in analytical reagent quality.

4. CHEMICAL PROPERTIES AND REACTIONS

Important Reactions:

1. Use as an Oxidizing Agent in Organic Synthesis:

CAN is widely used as a single electron transfer (SET) oxidizer in organic synthesis. For example, oxidation of alcohols to carbonyls:

RCH₂OH + 2 (NH₄)₂Ce(NO₃)₆ → RCHO + 2 (NH₄)₂Ce(NO₃)₅ + 2 HNO₃

2. Thermal Decomposition:

(NH₄)₂Ce(NO₃)₆ → CeO₂ + 2 N₂O + 4 HNO₃

3. Reaction with Reducing Agents:

CAN reacts with reducing agents such as iron(II):

(NH₄)₂Ce(NO₃)₆ + Fe(NO₃)₂ → (NH₄)₂Ce(NO₃)₅ + Fe(NO₃)₃

4. Hydrolysis in Water:

In aqueous solutions, Ce⁴⁺ ions hydrolyze:

Ce⁴⁺ + H₂O ⇌ Ce(OH)³⁺ + H⁺

5. APPLICATIONS AND INDUSTRIAL USES

5.1. Organic Synthesis (Most Important Application)

CAN is a versatile and powerful oxidizing agent in organic synthesis. It operates via a single electron transfer (SET) mechanism and enables selective oxidation of various functional groups.

5.2. Polymerization and Fine Chemicals

5.3. Analytical Chemistry

5.4. Electronics and Photolithography

5.5. Metal Surface Treatment

6. SECTORAL SUITABILITY TABLE

7. SAFETY AND TOXICOLOGY

Safety Precautions:

• Keep away from heat, sparks, and open flames.

• Store separately from combustible materials.

• Avoid dust formation.

• Work in well-ventilated areas.

• Use protective gloves, safety goggles, and dust mask.

• Wash hands thoroughly after handling.

• In case of eye contact, rinse with plenty of water for at least 15 minutes and seek medical attention.

• Avoid contact with organic materials at all times.

8. STORAGE AND HANDLING

9. TRANSPORT AND REGULATORY INFORMATION

10. QUALITY AND PURITY

11. RAW MATERIALS AND DOWNSTREAM PRODUCTS

11.1. Raw Materials (Upstream)

11.2. Downstream Products

12. FIRST AID MEASURES

13. FIREFIGHTING MEASURES

14. ACCIDENTAL RELEASE MEASURES

15. SUMMARY AND CRITICAL WARNINGS

SUMMARY:

Ammonium Cerium(IV) Nitrate (CAN) ((NH₄)₂Ce(NO₃)₆, CAS 16774-21-3) is a strong oxidizing salt composed of two Ammonium (NH₄⁺) cations and one [Ce(NO₃)₆]²⁻ complex anion. It appears as an orange-red crystalline solid, is highly soluble in water and polar organic solvents, and is hygroscopic (moisture-absorbing). The characteristic orange-red color arises from the charge transfer complex between Ce⁴⁺ ions and nitrate ligands.

Its most critical application is as a powerful and selective oxidizing agent in organic synthesis. CAN is widely used for oxidation of alcohols, aromatic nitration, oxidative cleavage, and radical reactions. It is also used in polymerization, analytical chemistry (cerimetry), photolithography, and specialty material production.

Under GHS classification, it is an oxidizer, harmful, and irritant (H272, H302, H315, H319). Due to its strong oxidizing properties, it must be kept away from organic and reducing substances. Due to its hygroscopic nature, it must be stored in a cool, dry environment in tightly closed packaging. Appropriate Personal Protective Equipment (PPE) must be used during handling to avoid inhalation of dust and contact with skin/eyes.

Key Properties:

CRITICAL WARNINGS:

1. Strong Oxidizing Property: CAN is a strong oxidizing agent. Contact with organic materials, reducing agents, and combustible materials must be strictly avoided. May intensify fire (H272). Therefore, it must be stored separately and away from combustible and reducing materials. Contact with organic solvents presents a fire and explosion risk.

2. Hygroscopic Property and Moisture Sensitivity: Highly hygroscopic and rapidly absorbs moisture from the air. Storage and weighing operations must not be performed in humid environments. After opening, the container must be quickly resealed and storage under an inert atmosphere (nitrogen, argon) is preferred. Moisture absorption compromises weighing accuracy and chemical stoichiometry. Color change (fading or browning) indicates product degradation.

3. Light Sensitivity: Color change (photochemical reduction) may occur upon exposure to light. It should be stored in dark-colored containers or protected from light.

4. Thermal Instability: Melts and decomposes at 107-108°C. Thermal decomposition releases toxic nitrogen oxides (NO, NO₂) and ammonia. Thermal processes should be conducted in well-ventilated areas or under fume hoods.

5. Structure and Purity: High purity (≥ 98.5%) is critical for organic synthesis and analytical applications. Ce³⁺ impurities reduce oxidizing power and negatively affect reaction selectivity.

6. Dust Control: The powder form can irritate the lungs if inhaled. Dust control measures must be implemented in the work area (closed systems, local exhaust ventilation) and appropriate respiratory protection (dust mask or N95/FFP2) must be used.

7. Aqueous Solution Acidity: Aqueous solutions are acidic due to hydrolysis. Appropriate protective equipment should be used when working with acidic solutions, and base solutions should be available for neutralization.

8. Environmental Precautions: As a water-soluble salt, release into the environment (particularly water sources) must be prevented. Cerium compounds may exhibit toxic effects in aquatic environments. Waste solutions must not be discharged into sewers and must be disposed of according to local regulations.

9. Regulatory Compliance: Registration and notification requirements under REACH and KKDİK must be observed. It is classified as Class 5.1 (Oxidizing substance) under ADR/IMDG/IATA, requiring special labeling and documentation during transport. Use in food, cosmetics, and textile sectors is strictly prohibited.

10. Special Warning for Organic Synthesis Applications: CAN is used as a single electron transfer (SET) oxidizer in organic synthesis. Reaction conditions (temperature, solvent, equivalents) must be carefully controlled. Excessive heating or rapid addition can cause uncontrolled reactions and fire/explosion hazards. An inert atmosphere (nitrogen, argon) should always be preferred when working with CAN.

11. Special Warning for Photolithography Applications: CAN solutions used as photoresist developers in the semiconductor industry should be prepared fresh and their stability regularly checked. Aged solutions lose oxidizing power and adversely affect process performance.

12. Storage Warning: After opening the package, the remaining product should be immediately transferred to a moisture-proof container. It must be stored separately from combustible, reducing, and organic materials. For long-term storage, storage under an inert atmosphere (nitrogen, argon) is recommended.

13. Preparation of CAN Solutions: When preparing CAN solutions, acidic water (dilute HNO₃) improves stability. In alkaline or neutral environments, CAN decomposes rapidly and forms Ce(OH)₄ precipitate.

14. Waste Disposal: CAN-containing wastes should be disposed of after reduction to Ce³⁺ using reducing agents (e.g., sodium thiosulfate, iron(II) salts). This neutralizes the oxidizing properties of the waste. Waste disposal must always be carried out in accordance with local regulations.

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 Ammonium Cerium(IV) Nitrate (CAN).