ГЕКСАФТОРАЦЕТИЛАЦЕТОНАТ БАРИЯ

Description

Barium hexafluoroacetylacetonate is an organometallic complex of barium with fluorinated beta-diketone, formula Ba(C5HF6O2)2. Belongs to a class of volatile barium coordination compounds used as precursors for gas-phase deposition of thin films.

Basic Attributes

• CAS No.: 314071-48-2
• Chemical formula: Ba(C5HF6O2)2
• Molecular Weight: 551.43
• Exact weight: 551.881394
• DSSTox ID: DTXSID00718693
• PSA specifications: 80.26000
• XLogP3: 3.98900

Physico-chemical characteristics

• Melting point: 250 °C (with decomposition, lit.)

Scope of application

Barium hexafluoroacetylacetonate and its polyester adducts are substantially more volatile than uncomplexed barium sources (vapor pressure on the order of 0.03 mm Hg at 150 °C for polyester adducts), making the compound a convenient precursor for chemical vapor deposition (CVD) and related barium-containing thin film deposition techniques. However, the use of fluorinated barium precursors for the production of barium strontium titanate (BST) is limited: the fluoride ion remaining in the oxide film can act as a charge carrier and worsen the dielectric constant of the resulting material, so non-fluorinated analogues of barium sources are often preferred for such tasks.

Why is the precursor volatile?

The problem with classic barium MOCVD precursors (for example, beta-diketonates without fluorination) is their low volatility and tendency to oligomerize, which causes uneven transfer of the substance into the gas phase. The introduction of fluorinated CF3 substituents into the acetylacetone ligand reduces the polarity and intermolecular interactions of the complex, increasing the vapor pressure and the stability of the vapor flow during evaporation, which is especially important for the uniform deposition of films of complex composition, including barium, strontium and titanium. Additionally, volatility can be increased by forming complex adducts with polyethers (crown ethers, glycols), which saturate the coordination sphere of barium and suppress the oligomerization of molecules in the solid phase.

Safety Information

• WGK Germany: 1
• Hazard class code: 20/22
• Safety instructions: 28
• Tags: Xn
• Precautionary statements: P261; P301+P312+P330
• Hazard statements: H302+H332 - harmful if swallowed and if inhaled

Storage and transportation

Store in a dry, cool, ventilated area in a tightly closed container, protected from moisture - fluorinated beta-diketonate barium complexes are sensitive to hydrolysis and gradually lose volatility when exposed to moist air. When working with powder, use protective gloves and, if dusty, respiratory protection, avoid getting inside. Transport in compliance with the general requirements for the transportation of organometallic compounds of barium; protect the container from mechanical damage and moisture.