HAFNIUM TETRACHLORIDE Hafnium(IV) chloride, 99%
Hafnium(IV) chloride is the inorganic compound with the formula HfCl4. This colourless solid is the precursor to most hafnium organometallic compounds.
Chemical formula:HfCl4
Molar mass:320.302 g/mol
Appearance:white crystalline solid
Density:3.89 g/cm3
Melting point:432 °C (810 °F; 705 K)
Application
Hafnium tetrachloride is the precursor to highly active catalysts for the Ziegler-Natta polymerization of alkenes, especially propylene. Typical catalysts are derived from tetrabenzylhafnium.
HfCl4 is an effective Lewis acid for various applications in organic synthesis. For example, ferrocene is alkylated with allyldimethylchlorosilane more efficiently using hafnium chloride relative to aluminium trichloride. The greater size of Hf may diminish HfCl4's tendency to complex to ferrocene.
HfCl4 increases the rate and control of 1,3-dipolar cycloadditions. It was found to yield better results than other Lewis acids when used with aryl and aliphatic aldoximes, allowing specific exo-isomer formation.
