BIS(ETHYLCYCLOPENTADIENYL)TUNGSTENDICHLORIDE

Identification

Bis(ethylcyclopentadienyl) tungsten dichloride is a metallocene complex of tungsten(IV) with two ethylcyclopentadienyl rings and two chlorine atoms. English name Bis(ethylcyclopentadienyl)tungstendichloride, CAS 83136-76-9, formula C14H18Cl2W. Synonyms: 1-ethyl-1,3-cyclopentadiene tungsten dichloride; dichlorobis[(1,2,3,4,5)-1-ethyl-2,4-cyclopentadien-1-yl]tungsten.

Basic Attributes

• CAS No.: 83136-76-9
• Chemical formula: C14H18Cl2W
• Molecular Weight: 441.04
• Exact weight: 440.029
• XLogP3: 4.9824

Physico-chemical characteristics

• Melting point: 156–160 °C (lit.)

Substance class and purpose

Tungsten metallocene of the same structural series as the ethylcyclopentadienyl complexes of zirconium, titanium and ruthenium is a heavy transition metal of group 6 in sandwich coordination between two alkyl-substituted cyclopentadienyl rings. The high XLogP3 value (4.9824) reflects the pronounced lipophilicity and solubility of the complex in non-polar organic media.

Applications

• organometallic precursor for chemical vapor deposition (CVD) of thin films of tungsten and tungsten carbide in microelectronics
• precursor for atomic layer deposition (ALD) of tungsten-containing barrier and conductive layers
• catalyst and precursor to tungsten-based catalysts for olefin metathesis and related reactions
• reagent in organometallic synthesis of other tungsten derivatives

Safety Information

• WGK Germany: 3

The source does not provide detailed data on hazard codes, transport markings and precautionary phrases. As a metallocene transition metal chloride complex, the substance should be considered sensitive to moisture and air and should be handled according to the general rules for working with metallocenes - in an inert atmosphere, using skin and eye protection.

Storage and transportation

Store in a hermetically sealed container, in a cool, dry place, under an inert gas, away from sources of moisture. The complex, like related metallocenes of tungsten and zirconium, decomposes upon prolonged contact with atmospheric oxygen with loss of activity as a precursor for precipitation processes.

Additionally

The ethyl group on the ring, compared to unsubstituted or methyl-substituted cyclopentadienyl ligands, increases the solubility of the complex in hydrocarbon solvents and reduces the melting point, which is in demand for liquid-phase dosing of the reagent in industrial CVD and ALD units, where a stable rate of supply of the precursor into the reaction chamber is important.

Related compounds series

In the same series of ethylcyclopentadienyl metallocenes there are analogues with ruthenium and other transition metals - replacing the central atom while maintaining the ligand environment makes it possible to obtain a family of precursors with similar properties for the deposition of films of different elemental compositions without revising the entire technology of reagent synthesis.