Triethyl Phosphite (CAS No: 122-52-1) is a versatile organophosphorus compound widely used as a reagent, solvent, and intermediate in organic synthesis. Known for its reducing and complexing abilities, this compound plays an important role in chemical manufacturing, pharmaceutical synthesis, and polymer chemistry.
In this article, we explore the analytical methods, purity standards, and characterization techniques that ensure Triethyl Phosphite meets the highest quality requirements for industrial and laboratory applications.
Chemical Name: Triethyl Phosphite
CAS Number: 122-52-1
Molecular Formula: C₆H₁₅O₃P
Molecular Weight: 166.16 g/mol
Synonyms: Phosphorous acid triethyl ester, Ethyl phosphite
Appearance: Colorless to pale yellow liquid with a characteristic odor
Triethyl Phosphite is primarily used as a ligand in coordination chemistry, a reducing agent in organic synthesis, and a starting material for phosphonate and phosphine derivatives.
Property |
Value |
|---|---|
CAS No. |
122-52-1 |
Molecular Formula |
C₆H₁₅O₃P |
Molecular Weight |
166.16 g/mol |
Boiling Point |
156–158°C |
Density |
0.971 g/cm³ at 25°C |
Refractive Index |
1.405–1.408 |
Flash Point |
49°C (closed cup) |
Solubility |
Miscible with most organic solvents (alcohols, ethers, benzene, chloroform) |
To ensure product quality and purity, several analytical methods are employed for Triethyl Phosphite characterization:
Gas Chromatography is the primary method used to determine the purity and impurity profile of Triethyl Phosphite.
Detection: Flame Ionization Detector (FID)
Result: Typical purity ≥ 98–99%
¹H NMR and ³¹P NMR are used to confirm structural identity.
The presence of a sharp ³¹P resonance at characteristic chemical shifts confirms the phosphite functional group.
Infrared analysis identifies characteristic functional groups such as P–O–C and P=O bonds.
Key absorption peaks appear near 1050–1020 cm⁻¹ (P–O stretching).
Used to verify molecular weight and confirm molecular fragmentation patterns typical of Triethyl Phosphite.
Determines carbon, hydrogen, and phosphorus composition to ensure chemical formula consistency.
High-purity Triethyl Phosphite is crucial for reliable reactions and consistent product quality.
Specification |
Typical Value |
|---|---|
Purity (GC) |
≥ 98.0% |
Acid Value |
≤ 0.1 mg KOH/g |
Moisture (Karl Fischer) |
≤ 0.05% |
Appearance |
Clear, colorless liquid |
Odor |
Mild ester-like smell |
For sensitive applications, extra-pure or analytical-grade Triethyl Phosphite is used, ensuring minimal oxidation or hydrolysis products.
Comprehensive characterization confirms the molecular identity and stability of Triethyl Phosphite.
Spectroscopic Characterization: NMR (¹H, ¹³C, ³¹P) confirms the ethoxy groups and phosphorus environment.
Thermal Analysis (TGA/DSC): Determines decomposition onset and thermal stability.
Chromatographic Profiling: Confirms single-component consistency and absence of by-products.
These analyses ensure the compound meets research-grade or industrial-grade specifications.
Although Triethyl Phosphite is relatively stable, it is sensitive to oxidation and moisture.
To maintain its purity and performance:
Storage: Keep in airtight containers under an inert gas (nitrogen or argon).
Temperature: Store at room temperature (15–25°C) in a dry place.
Avoid: Exposure to air, light, or water.
Safety: Use gloves and safety goggles. Work in a well-ventilated area or fume hood.
GHS Classification:
Hazards: Irritant, flammable liquid
Precautions: Avoid inhalation and contact with skin or eyes.
Triethyl Phosphite (CAS No: 122-52-1) is an essential reagent in many fields:
Used in Michaelis–Arbuzov reactions to synthesize phosphonates.
Functions as a reducing agent for converting nitro compounds or halides.
Serves as an intermediate in API synthesis.
Used for the formation of phosphorus-containing drug derivatives.
Employed as a stabilizer and antioxidant in polymer production.
Acts as a flame retardant additive in certain materials.
Functions as a ligand for transition metal complexes due to its lone pair on phosphorus.
Triethyl Phosphite (CAS No: 122-52-1) remains a fundamental reagent across multiple scientific disciplines. Its well-defined analytical profile, high purity, and versatile reactivity make it indispensable in research and industrial chemistry.
Through precise analytical methods, strict purity control, and proper characterization, Triethyl Phosphite continues to serve as a reliable cornerstone for advanced synthesis and innovation.
