Lithium SelenateCAS #: 15593-52-9

Synonyms 

Dilithium selenate; Selenic acid, dilithium salt; dilithium salt

Compound Formula: LiO4Se 

Molecular Weight: 156.8396 

Appearance: solid 

Melting Point: N/A 

Boiling Point: N/A 

Density: N/A 

Solubility in H2O: N/A 

Exact Mass: 157.928188 

Monoisotopic Mass: 157.928192 Da

Product Introduction: Ammonium Hexafluorophosphate (NH₄PF₆, CAS #: 15593-52-9)

Ammonium hexafluorophosphate, with the chemical formula NH₄PF₆ and CAS number 15593-52-9, is an inorganic salt composed of ammonium cations (NH₄⁺) and hexafluorophosphate anions (PF₆⁻). This white, crystalline compound is valued for its high solubility in polar organic solvents, thermal stability, and versatility in industrial and research applications. While less prominent than its lithium or sodium analogs in battery technologies, NH₄PF₆ plays a critical role in electroplating, ionic liquid synthesis, and as a reagent in analytical chemistry, leveraging its unique ionic properties and compatibility with diverse chemical systems.

Chemical & Physical Properties

NH₄PF₆ exhibits a set of properties that define its utility across applications:

Solubility: Highly soluble in polar organic solvents such as acetonitrile, dimethylformamide (DMF), and propylene carbonate (PC), with solubility exceeding 1 M in many cases. It is also soluble in water (approximately 45 g/100 mL at 20°C), though prolonged exposure to moisture can induce slow hydrolysis.

Thermal Stability: Decomposes at temperatures above 200°C, releasing ammonia (NH₃), phosphorus pentafluoride (PF₅), and hydrogen fluoride (HF). This stability is higher than that of many ammonium salts, making it suitable for moderate-temperature processes.

Hygroscopicity: Moderately hygroscopic, absorbing moisture from the air to form hydrated crystals. This necessitates storage in dry environments to prevent caking and degradation.

Density & Structure: Has a density of 2.18 g/cm³ and a molar mass of 163.0 g/mol, with a cubic crystal structure that contributes to its stability in anhydrous conditions.

Electrochemical Behavior: Exhibits good ionic conductivity in solution, supporting its use as an electrolyte additive and in electroplating baths, where it facilitates ion transport.

Key Applications

Ammonium hexafluorophosphate (CAS 15593-52-9) finds applications across diverse fields, driven by its ionic properties:

Electroplating and Surface Finishing: Used as an additive in electroplating baths for noble metals (e.g., gold, silver, and palladium). The PF₆⁻ anion helps regulate metal ion solubility, improving coating uniformity and adhesion. In gold plating, NH₄PF₆ enhances the brightness and corrosion resistance of the deposited layer, making it valuable for jewelry, electronics, and decorative coatings.

Ionic Liquid Synthesis: Serves as a precursor in the preparation of ammonium-based ionic liquids, which are used as green solvents in chemical synthesis, catalysis, and energy storage. These ionic liquids exhibit low volatility, high thermal stability, and tunable properties, with NH₄PF₆-derived variants finding use in battery electrolytes and gas separation processes.

Analytical Chemistry: Employed as a reagent in ion chromatography for the separation and detection of cations in environmental and biological samples. Its ability to form stable complexes with metal ions makes it useful in spectrophotometric analysis, particularly for quantifying trace metals in solution.

Organic Synthesis: Acts as a fluorinating agent and catalyst in organic reactions, facilitating the formation of carbon-fluorine bonds in pharmaceutical intermediates and agrochemicals. It also promotes certain cyclization reactions, enabling the synthesis of complex heterocyclic compounds.

Research and Development: Used in laboratory studies of electrolyte systems, including ammonium-ion batteries—a emerging technology for grid storage. NH₄PF₆-based electrolytes support ammonium ion transport, though research is ongoing to improve cycle life and stability.

Advantages & Limitations

NH₄PF₆ offers distinct benefits alongside specific considerations:

Ionic Versatility: The ammonium cation provides unique solubility and reactivity compared to alkali metal cations, making it suitable for applications where alkali metals are incompatible (e.g., certain catalytic reactions).

Cost-Effectiveness: More affordable than lithium or sodium hexafluorophosphates, with production costs leveraging the abundance of ammonium compounds, supporting its use in large-scale processes like electroplating.

Stability in Organic Media: Maintains stability in a wide range of organic solvents, enabling its use in non-aqueous reactions where water-sensitive reagents are involved.

Limitations: Hygroscopicity requires careful storage and handling to prevent hydrolysis, which generates toxic HF. Its decomposition at high temperatures restricts use in extreme-heat applications, and the release of ammonia during decomposition necessitates proper ventilation.

Synthesis & Quality Control

NH₄PF₆ is produced through metathesis reactions to ensure high purity:

Reaction of Ammonium Fluoride with Phosphorus Pentafluoride: Ammonium fluoride (NH₄F) reacts with PF₅ in anhydrous hydrogen fluoride (HF) solvent: NH₄F + PF₅ → NH₄PF₆. The product is isolated via crystallization and dried under vacuum to remove residual HF.

Neutralization Route: In aqueous systems, ammonium hydroxide (NH₄OH) reacts with hydrofluoric acid (HF) and phosphoric acid (H₃PO₄), followed by precipitation: H₃PO₄ + 6HF + NH₄OH → NH₄PF₆ + 4H₂O.

Quality control includes:

Ion chromatography to verify PF₆⁻ content (typically 99.0–99.5% purity for industrial grades).

X-ray diffraction (XRD) to detect crystalline impurities like NH₄F or (NH₄)₃PO₄.

Moisture analysis (Karl Fischer) to ensure <0.1% water, critical for preventing hydrolysis in organic solvent applications.

Safety & Handling

Proper handling of NH₄PF₆ is essential due to its fluoride content and potential for ammonia release:

Toxicity: Inhalation or ingestion can cause fluoride poisoning, with symptoms including respiratory irritation, nausea, and bone damage. Hydrolysis releases HF, a corrosive gas that causes severe burns to skin and eyes. Decomposition at high temperatures releases ammonia, which is irritating to the respiratory system.

Handling: Wear chemical-resistant gloves (nitrile or PTFE), goggles, and a dust mask when working with powders. Use in well-ventilated fume hoods to avoid exposure to HF and ammonia.

Storage: Keep in airtight, moisture-proof containers in a cool, dry area, separate from strong acids, bases, and oxidizing agents.

Disposal: Dispose of waste as hazardous material in accordance with local regulations for fluoride and ammonium compounds. Neutralize spills with calcium carbonate to form insoluble CaF₂ before cleanup.

Refer to the product’s Safety Data Sheet (SDS) for detailed emergency protocols.

Packaging & Availability

NH₄PF₆ is available in forms tailored to industrial and research needs:

Crystalline Powder: Packaged in 1kg–25kg HDPE bottles or drums with moisture-proof liners for industrial use.

High-Purity Grades: 99.9% purity variants in 100g–5kg containers for laboratory and electronics applications, with ultra-low metal impurities (<10 ppm).

Solution Form: Pre-dissolved in organic solvents (e.g., 0.5 M in acetonitrile) in 1L–20L containers for immediate use in electroplating and synthesis.

Global production is concentrated in regions with robust chemical manufacturing sectors, including China, Europe, and the United States. Suppliers offer flexible quantities to meet the needs of both small-scale research and large-scale industrial operations.

For technical specifications, pricing, or custom formulations, contact our team specializing in fluorinated salts for industrial and research applications.

Health & Safety Information 

Signal Word: N/A 

Hazard Statements: N/A 

Hazard Codes: N/A 

Risk Codes: N/A 

Safety Statements: N/A 

Transport Information: N/A

Chemical Identifiers 

Linear Formula: LiSeO4 

Pubchem CID: 167311 

MDL Number: N/A 

EC No.: 239-668-5 

IUPAC Name: dilithium selenate 

Beilstein/Reaxys No.: N/A 

SMILES: [Li+].[Li+].[O-][Se]([O-])(=O)=O 

InchI Identifier: InChI=1S/2Li.H2O4Se/c;;1-5(2,3)4/h;;(H2,1,2,3,4)/q2*+1;/p-2 

InchI Key: JXTNYTBZEWFKNR-UHFFFAOYSA-L

Packing of Standard Packing: 

Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 735 gallon liquid totes Special package is available on request.